Volume ,2023 Issue 5
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- Water circulation response and water demand situation change under “DoubleCarbon” strategy
- Research progress and the prospect of a complex relationshipbetween water-energy-carbon emission
- Carbon dioxide emission equivalent analysis method of water resource behaviorsand its application
- Innovation and design of incremental water rights conversion mode in water diversion project intake area
- Ecological regulation of algae in Middle Route of South-to-North Water Diversion Project
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- Practice and countermeasures of the great protection of the Yangtze River
- Driving effect evolution and spatial differentiation of water use change in China
- Simulation of pipeline network drainage at urban community scales based on SWMM:A case study in Fuzhou City
- Interaction mechanism between urbanization and ecological security in nine provinces of the Yellow River basin
- Urban waterlogging simulation and rainwater pipe network system evaluation based on SWMM and SCS method
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Abstract:
Agricultural?water?consumption?accounts?for?over?70%?of?the?world's?water?consumption.?For?a?long time,?promoting?water-saving?irrigation?technology?and?improving?agricultural?water?efficiency?have?been?regarded as?effective?methods?to?reduce?agricultural?water?consumption?and?alleviate?regional?water?scarcity.?However,?an increasing?number?of?studies?have?shown?that?with?the?application?of?water-saving?technology?and?the?improvement of?water-saving?levels,?the?shortage?of?water?resources?worldwide?has?become?even?more?severe,?resulting?in?the paradox?of?irrigation?efficiency.?The?emergence?of?the?paradox?of?irrigation?efficiency?results?from?various?factors such?as?hydrology,?economy,?society,?institutions,?and?management,?and?the?expansion?of?irrigation?area?is?an important?reason?for?the?paradox.?Revealing?the?mechanism?of?the?paradox?of?irrigation?efficiency?is?the?basis?for improving?water?and?land?resources?management?in?the?river?basins.?Tarim?River?basin?is?located?in?an?inland?arid area?with?scarce?water?resources,?and?the?natural?ecology?is?very?fragile.?In?the?recent?comprehensive?management of?the?Tarim?River?basin,?nearly?half?of?the?investment?was?spent?on?water-saving?renovation?in?irrigation?areas. However, ?the ?expected ?results ?were ?not ?achieved. ?The ?expansion ?of ?irrigation ?area ?resulted ?in ?the ?widespread phenomenon?of?"reclaiming?land?while?controlling"?and?"saving?water?while?consuming?water".?Under?the?condition of?a?certain?amount?of?total?water?resources,?there?is?a?game?competition?relationship?between?natural?and?artificial systems?regarding?water?consumption.?Therefore,?it?is?urgent?to?explore?the?evolution?of?water?consumption?with water ?use ?efficiency ?in ?water-saving ?development ?between ?natural ?oasis ?ecosystems ?and ?artificial ?oasis ?socio- economic?systems. ??????The?Tarim?River?basin,?the?most?apparent?contradiction?in?water?and?land?resources,?was?taken?as?an?example. The?rapid?development?of?water-saving?technology?from?1990?to?2020?was?selected?as?the?study?time.?Under?the conditions?of?consistent?water?resources,?social?economy,?and?water-saving?levels?in?the?basin,?two?cases?was?set?up, i.e.,?the?actual?case?with?irrigation?area?expansion?and?the?ideal?case?with?irrigated?area?maintenance.?The?basin’s water?consumption?and?water?use?efficiency?varying?with?the?development?of?water-saving?irrigation?were?analyzed and?compared?with?the?two?cases. ??????The?results?show?that?in?the?past?30?years,?the?irrigation?water?use?efficiency?of?the?basin?has?increased?from?0.28 to?0.55,?the?gross?irrigation?quota?has?been?reduced?by?twice,?and?the?water-saving?level?has?been?significantly improved.?In?the?actual?case,?3.6?billion?m3?of?net?water?savings?have?been?used?to?expand?irrigation?area,?resulting in?more?than?doubling?of?irrigation?area?and?water?consumption.?The?area?ratio?of?artificial?and?natural?oases?has changed?from?40∶60?to?55∶45,?and?the?water?consumption?ratio?has?changed?from?4∶6?to?6∶4.?The?proportion of?oasis?water?consumption?to?water?resources?has?increased?from?72%?to?91%,?resulting?in?a?severe?paradox?of irrigation?efficiency.?In?the?ideal?case,?the?irrigation?water?consumption?is?reduced,?the?area?and?water?consumption ratio?of?artificial?and?natural?oases?are?maintained?at?around?4∶6,?and?the?proportion?of?oasis?water?consumption?to water?resources?is?70%,?resulting?in?an?actual?water?saving?of?2.4?billion?m3,?avoiding?the?occurrence?of?the?paradox of?irrigation?efficiency. ??????The?emergence?of?the?paradox?of?irrigation?efficiency?is?the?complete?result?of?factors?such?as?great?water conditions,?water-saving?development,?planting?structure?adjustment,?and?irrigation?area?expansion.?In?the?past?30 years,?the?expansion?of?the?irrigation?area?has?played?a?leading?role?in?the?emergence?of?the?paradox?of?irrigation efficiency?in?the?Tarim?River?basin.?In?order?to?avoid?the?occurrence?of?the?paradox?of?irrigation?efficiency,?it?is necessary?to?manage?water?resources?strictly,?adhere?to?the?principle?of?"water?settling?land",?and?promote?the balanced?development?of?soil?and?water?resources?in?arid?inland?river?basins.
Agricultural?water?consumption?accounts?for?over?70%?of?the?world's?water?consumption.?For?a?long time,?promoting?water-saving?irrigation?technology?and?improving?agricultural?water?efficiency?have?been?regarded as?effective?methods?to?reduce?agricultural?water?consumption?and?alleviate?regional?water?scarcity.?However,?an increasing?number?of?studies?have?shown?that?with?the?application?of?water-saving?technology?and?the?improvement of?water-saving?levels,?the?shortage?of?water?resources?worldwide?has?become?even?more?severe,?resulting?in?the paradox?of?irrigation?efficiency.?The?emergence?of?the?paradox?of?irrigation?efficiency?results?from?various?factors such?as?hydrology,?economy,?society,?institutions,?and?management,?and?the?expansion?of?irrigation?area?is?an important?reason?for?the?paradox.?Revealing?the?mechanism?of?the?paradox?of?irrigation?efficiency?is?the?basis?for improving?water?and?land?resources?management?in?the?river?basins.?Tarim?River?basin?is?located?in?an?inland?arid area?with?scarce?water?resources,?and?the?natural?ecology?is?very?fragile.?In?the?recent?comprehensive?management of?the?Tarim?River?basin,?nearly?half?of?the?investment?was?spent?on?water-saving?renovation?in?irrigation?areas. However, ?the ?expected ?results ?were ?not ?achieved. ?The ?expansion ?of ?irrigation ?area ?resulted ?in ?the ?widespread phenomenon?of?"reclaiming?land?while?controlling"?and?"saving?water?while?consuming?water".?Under?the?condition of?a?certain?amount?of?total?water?resources,?there?is?a?game?competition?relationship?between?natural?and?artificial systems?regarding?water?consumption.?Therefore,?it?is?urgent?to?explore?the?evolution?of?water?consumption?with water ?use ?efficiency ?in ?water-saving ?development ?between ?natural ?oasis ?ecosystems ?and ?artificial ?oasis ?socio- economic?systems. ??????The?Tarim?River?basin,?the?most?apparent?contradiction?in?water?and?land?resources,?was?taken?as?an?example. The?rapid?development?of?water-saving?technology?from?1990?to?2020?was?selected?as?the?study?time.?Under?the conditions?of?consistent?water?resources,?social?economy,?and?water-saving?levels?in?the?basin,?two?cases?was?set?up, i.e.,?the?actual?case?with?irrigation?area?expansion?and?the?ideal?case?with?irrigated?area?maintenance.?The?basin’s water?consumption?and?water?use?efficiency?varying?with?the?development?of?water-saving?irrigation?were?analyzed and?compared?with?the?two?cases. ??????The?results?show?that?in?the?past?30?years,?the?irrigation?water?use?efficiency?of?the?basin?has?increased?from?0.28 to?0.55,?the?gross?irrigation?quota?has?been?reduced?by?twice,?and?the?water-saving?level?has?been?significantly improved.?In?the?actual?case,?3.6?billion?m3?of?net?water?savings?have?been?used?to?expand?irrigation?area,?resulting in?more?than?doubling?of?irrigation?area?and?water?consumption.?The?area?ratio?of?artificial?and?natural?oases?has changed?from?40∶60?to?55∶45,?and?the?water?consumption?ratio?has?changed?from?4∶6?to?6∶4.?The?proportion of?oasis?water?consumption?to?water?resources?has?increased?from?72%?to?91%,?resulting?in?a?severe?paradox?of irrigation?efficiency.?In?the?ideal?case,?the?irrigation?water?consumption?is?reduced,?the?area?and?water?consumption ratio?of?artificial?and?natural?oases?are?maintained?at?around?4∶6,?and?the?proportion?of?oasis?water?consumption?to water?resources?is?70%,?resulting?in?an?actual?water?saving?of?2.4?billion?m3,?avoiding?the?occurrence?of?the?paradox of?irrigation?efficiency. ??????The?emergence?of?the?paradox?of?irrigation?efficiency?is?the?complete?result?of?factors?such?as?great?water conditions,?water-saving?development,?planting?structure?adjustment,?and?irrigation?area?expansion.?In?the?past?30 years,?the?expansion?of?the?irrigation?area?has?played?a?leading?role?in?the?emergence?of?the?paradox?of?irrigation efficiency?in?the?Tarim?River?basin.?In?order?to?avoid?the?occurrence?of?the?paradox?of?irrigation?efficiency,?it?is necessary?to?manage?water?resources?strictly,?adhere?to?the?principle?of?"water?settling?land",?and?promote?the balanced?development?of?soil?and?water?resources?in?arid?inland?river?basins.
Abstract:
Rainfall?is?a?direct?factor?in?the?formation?of?flood,?and?the?combination?of?accurate?rainfall?forecast?data in?the?long?forecast?period?and?hydrological?model?is?the?key?to?improve?the?accuracy?of?flood?forecast?and?increase the?forecast?period,?which?can?strive?for?a?longer?emergency?response?time?for?flood?control?and?disaster?reduction. Rainfall?forecast?data?mainly?come?from?meteorological?radar,?satellite?cloud?image?and?numerical?weather?forecast products.?Although?the?meteorological?observation?technology?and?equipment?have?made?great?progress?in?the?past few?decades,?due?to?the?chaos?of?atmospheric?system,?the?error?of?atmospheric?initial?data?and?the?error?of?model,?the rainfall ?forecast ?products ?inevitably ?have ?large ?errors ?and ?limitations, ?and ?need ?to ?be ?effectively ?corrected ?to improve?its?accuracy?and?reliability.?The?research?took?12?stations?in?Chaobai?River?basin?as?the?research?object,?the forecast?precipitation?data?of?12?stations?in?different?forecast?periods?in?the?next?12?hours?were?selected.?Rainfall error?correction?models?based?on?support?vector?machine,?random?forest?and?multilayer?perceptron?in?different forecast?periods?were?constructed.?The?model?input?is?the?rainfall?forecast?data?of?the?corresponding?grid?of?the station?and?its?surrounding?8?grids,?and?the?model?parameters?are?estimated?by?Bayesian?optimization?technology. The?root?mean?square?error?and?deterministic?coefficient?indexes?were?used?to?evaluate?the?correction?effect?of?each model?on?precipitation?forecast?in?different?forecast?periods.?The?results?showed?that?the?prediction?accuracy?of uncorrected ?original ?forecast ?was ?poor ?in ?different ?forecast ?periods. ?Each ?error ?correction ?model ?has ?a ?good correction?effect?on?rainfall?in?different?forecast?periods.?After?correction?by?support?vector?machine?model,?random forest?model?and?multilayer?perceptron?model,?the?average?root?mean?square?error?decreases?by?54.2%,?50.0%?and 20.8%,?respectively.?During?the?validation?period,?the?reduction?was?42.9%,?33.3%?and?14.3%,?respectively.?The average?certainty?coefficient?also?increased?significantly?in?both?the?rate?period?and?the?validation?period.?Among?the three?error?correction?models,?support?vector?machine?model?is?the?best,?followed?by?random?forest?model.?Based?on support?vector?machine,?random?forest?and?multi-layer?perceptron?model,?combined?with?Bayesian?optimization technology,?the?error?correction?models?of?forecast?rainfall?data?in?different?forecast?periods?were?constructed?to correct?and?analyze?the?forecast?rainfall?data?of?12?stations?in?the?Chaobai?River?basin?in?12?different?forecast periods.?The?root?mean?square?error?and?deterministic?coefficient?were?used.?The?correction?effect?is?good?and?the accuracy?of?rainfall?forecast?is?improved,?and?it?can?be?used?as?a?reference?for?the?numerical?rainfall?correction?of other?watershed?stations.
Rainfall?is?a?direct?factor?in?the?formation?of?flood,?and?the?combination?of?accurate?rainfall?forecast?data in?the?long?forecast?period?and?hydrological?model?is?the?key?to?improve?the?accuracy?of?flood?forecast?and?increase the?forecast?period,?which?can?strive?for?a?longer?emergency?response?time?for?flood?control?and?disaster?reduction. Rainfall?forecast?data?mainly?come?from?meteorological?radar,?satellite?cloud?image?and?numerical?weather?forecast products.?Although?the?meteorological?observation?technology?and?equipment?have?made?great?progress?in?the?past few?decades,?due?to?the?chaos?of?atmospheric?system,?the?error?of?atmospheric?initial?data?and?the?error?of?model,?the rainfall ?forecast ?products ?inevitably ?have ?large ?errors ?and ?limitations, ?and ?need ?to ?be ?effectively ?corrected ?to improve?its?accuracy?and?reliability.?The?research?took?12?stations?in?Chaobai?River?basin?as?the?research?object,?the forecast?precipitation?data?of?12?stations?in?different?forecast?periods?in?the?next?12?hours?were?selected.?Rainfall error?correction?models?based?on?support?vector?machine,?random?forest?and?multilayer?perceptron?in?different forecast?periods?were?constructed.?The?model?input?is?the?rainfall?forecast?data?of?the?corresponding?grid?of?the station?and?its?surrounding?8?grids,?and?the?model?parameters?are?estimated?by?Bayesian?optimization?technology. The?root?mean?square?error?and?deterministic?coefficient?indexes?were?used?to?evaluate?the?correction?effect?of?each model?on?precipitation?forecast?in?different?forecast?periods.?The?results?showed?that?the?prediction?accuracy?of uncorrected ?original ?forecast ?was ?poor ?in ?different ?forecast ?periods. ?Each ?error ?correction ?model ?has ?a ?good correction?effect?on?rainfall?in?different?forecast?periods.?After?correction?by?support?vector?machine?model,?random forest?model?and?multilayer?perceptron?model,?the?average?root?mean?square?error?decreases?by?54.2%,?50.0%?and 20.8%,?respectively.?During?the?validation?period,?the?reduction?was?42.9%,?33.3%?and?14.3%,?respectively.?The average?certainty?coefficient?also?increased?significantly?in?both?the?rate?period?and?the?validation?period.?Among?the three?error?correction?models,?support?vector?machine?model?is?the?best,?followed?by?random?forest?model.?Based?on support?vector?machine,?random?forest?and?multi-layer?perceptron?model,?combined?with?Bayesian?optimization technology,?the?error?correction?models?of?forecast?rainfall?data?in?different?forecast?periods?were?constructed?to correct?and?analyze?the?forecast?rainfall?data?of?12?stations?in?the?Chaobai?River?basin?in?12?different?forecast periods.?The?root?mean?square?error?and?deterministic?coefficient?were?used.?The?correction?effect?is?good?and?the accuracy?of?rainfall?forecast?is?improved,?and?it?can?be?used?as?a?reference?for?the?numerical?rainfall?correction?of other?watershed?stations.
Abstract:
In?the?context?of?global?climate?change,?excessive?deforestation,?urban?construction?and?irrational?use?of water?resources?have?been?carried?out?by?human?beings?for?a?long?time,?and?the?phenomena?of?water?resource shortage, ?water ?environment ?pollution, ?water ?ecology ?deterioration ?and ?river ?closure ?have ?become ?increasingly prominent.?The?original?ecosystems?in?many?river?basins?were?destroyed?and?the?ecosystem?service?functions?were reduced.?Water?conservation?capacity?has?important?service?functions?such?as?regulating?runoff,?purifying?water quality,?and?regulating?and?storing?flood?water.?As?a?first-level?tributary?of?the?Yellow?River,?the?Qinhe?River?is?an important ?part ?of ?the ?ecosystem ?along ?the ?river. ?However, ?due ?to ?the ?influence ?of ?climate ?change ?and ?human activities?in?recent?years,?the?land?use?change?of?the?Qinhe?River?basin?is?significant,?and?the?inter-annual?variation characteristics ?of ?water ?conservation ?function ?are ?gradually ?complicated. ?Therefore, ?exploring ?the ?water conservation?capacity?of?Qinhe?River?basin?in?the?changing?environment?can?provide?scientific?reference?value?for ecological?protection?and?high-quality?development?strategy?of?the?Yellow?River?basin. ??????SWAT?model?was?constructed,?and?the?land?use?data?set?of?the?Qinhe?River?basin?in?2030?was?predicted?based on?the?CA-Markov?model?to?analyze?and?predict?the?temporal?and?spatial?changes?of?water?conservation?capacity?in the?Qinhe?River?basin.?Combined?with?CMIP6?meteorological?data,?the?hydrological?factors?of?the?river?basin simulated?by?the?SWAT?model?were?obtained?according?to?the?principle?of?water?balance.?The?temporal?and?spatial changes?in?water?conservation?in?the?past?and?future?years?were?calculated.?In?addition,?by?calculating?the?ratio?of water?conservation?and?precipitation,?the?index?of?water?conservation?rate?was?introduced?to?further?quantify?the water?conservation?capacity?of?the?basin?for?storing?precipitation?and?supplying?water. ??????The ?results ?show ?that ?the ?average ?annual ?water ?conservation ?is ?49 ?mm ?and ?the ?average ?annual ?water conservation ?rate ?is ?8%?in ?the ?Qinhe ?River ?basin. ?From ?2010 ?to ?2016, ?water ?conservation ?showed ?a ?trend ?of fluctuation ?and ?increase, ?and ?the ?water ?conservation ?is ?consistent ?with ?the ?inter-annual ?variation ?trend ?of precipitation.?The?spatial?distribution?characteristics?of?water?conservation?and?water?conservation?rate?in?2010, 2015,?and?2025?are?similar,?showing?a?trend?of?increasing?from?upstream?to?downstream?and?decreasing?from?west to?east.?However,?the?spatial?distribution?characteristics?of?water?conservation?and?water?conservation?rate?in?2030 are?different?from?other?years,?and?the?overall?trend?is?decreasing?from?the?upstream?to?the?downstream,?and?the water?conservation?and?water?conservation?rate?are?negative?in?the?downstream?multi-section?basins. ??????The?analysis?showed?that?the?spatial?distribution?of?water?conservation?rate?and?water?conservation?in?the?basin has?a?good?consistency,?and?there?are?negative?values?in?the?sub-basins,?indicating?that?the?water?conservation capacity?of?the?basin?is?low,?the?ecological?environment?is?damaged?to?a?high?degree,?and?the?ecological?water consumption?in?the?river?is?insufficient,?which?is?in?line?with?the?actual?situation?that?the?relevant?river?reaches?were cut?off.
In?the?context?of?global?climate?change,?excessive?deforestation,?urban?construction?and?irrational?use?of water?resources?have?been?carried?out?by?human?beings?for?a?long?time,?and?the?phenomena?of?water?resource shortage, ?water ?environment ?pollution, ?water ?ecology ?deterioration ?and ?river ?closure ?have ?become ?increasingly prominent.?The?original?ecosystems?in?many?river?basins?were?destroyed?and?the?ecosystem?service?functions?were reduced.?Water?conservation?capacity?has?important?service?functions?such?as?regulating?runoff,?purifying?water quality,?and?regulating?and?storing?flood?water.?As?a?first-level?tributary?of?the?Yellow?River,?the?Qinhe?River?is?an important ?part ?of ?the ?ecosystem ?along ?the ?river. ?However, ?due ?to ?the ?influence ?of ?climate ?change ?and ?human activities?in?recent?years,?the?land?use?change?of?the?Qinhe?River?basin?is?significant,?and?the?inter-annual?variation characteristics ?of ?water ?conservation ?function ?are ?gradually ?complicated. ?Therefore, ?exploring ?the ?water conservation?capacity?of?Qinhe?River?basin?in?the?changing?environment?can?provide?scientific?reference?value?for ecological?protection?and?high-quality?development?strategy?of?the?Yellow?River?basin. ??????SWAT?model?was?constructed,?and?the?land?use?data?set?of?the?Qinhe?River?basin?in?2030?was?predicted?based on?the?CA-Markov?model?to?analyze?and?predict?the?temporal?and?spatial?changes?of?water?conservation?capacity?in the?Qinhe?River?basin.?Combined?with?CMIP6?meteorological?data,?the?hydrological?factors?of?the?river?basin simulated?by?the?SWAT?model?were?obtained?according?to?the?principle?of?water?balance.?The?temporal?and?spatial changes?in?water?conservation?in?the?past?and?future?years?were?calculated.?In?addition,?by?calculating?the?ratio?of water?conservation?and?precipitation,?the?index?of?water?conservation?rate?was?introduced?to?further?quantify?the water?conservation?capacity?of?the?basin?for?storing?precipitation?and?supplying?water. ??????The ?results ?show ?that ?the ?average ?annual ?water ?conservation ?is ?49 ?mm ?and ?the ?average ?annual ?water conservation ?rate ?is ?8%?in ?the ?Qinhe ?River ?basin. ?From ?2010 ?to ?2016, ?water ?conservation ?showed ?a ?trend ?of fluctuation ?and ?increase, ?and ?the ?water ?conservation ?is ?consistent ?with ?the ?inter-annual ?variation ?trend ?of precipitation.?The?spatial?distribution?characteristics?of?water?conservation?and?water?conservation?rate?in?2010, 2015,?and?2025?are?similar,?showing?a?trend?of?increasing?from?upstream?to?downstream?and?decreasing?from?west to?east.?However,?the?spatial?distribution?characteristics?of?water?conservation?and?water?conservation?rate?in?2030 are?different?from?other?years,?and?the?overall?trend?is?decreasing?from?the?upstream?to?the?downstream,?and?the water?conservation?and?water?conservation?rate?are?negative?in?the?downstream?multi-section?basins. ??????The?analysis?showed?that?the?spatial?distribution?of?water?conservation?rate?and?water?conservation?in?the?basin has?a?good?consistency,?and?there?are?negative?values?in?the?sub-basins,?indicating?that?the?water?conservation capacity?of?the?basin?is?low,?the?ecological?environment?is?damaged?to?a?high?degree,?and?the?ecological?water consumption?in?the?river?is?insufficient,?which?is?in?line?with?the?actual?situation?that?the?relevant?river?reaches?were cut?off.
Abstract:
Hebei?Province?is?an?important?ecological?barrier?in?northern?China?and?an?important?support?for?the coordinated?development?of?Beijing,?Tianjin?and?Hebei.?However,?its?water?resources?problem?was?prominent,?the per?capita?possession?was?low,?the?spatial?and?temporal?distribution?was?uneven,?and?the?contradiction?between supply?and?demand?of?water?resources?was?increasing.?With?the?continuous?development?of?social?economy,?the intensity?and?pressure?of?water?resources?development?and?utilization?were?increasing?year?by?year,?and?the?problem of?water?ecological?environment?was?becoming?more?and?more?serious.?In?order?to?objectively?and?effectively evaluate?the?water?resources?security?degree?of?Hebei?Province,?ensure?that?the?natural?circulation?system?of?water resources ?can ?meet ?the ?natural ?guarantee ?function ?of ?national ?or ?regional ?development ?needs ?without ?being destroyed?or?threatened?by?people. ??????Based ?on ?the ?DPSIR ?model, ?the ?evaluation ?system ?of ?water ?resources ?security ?degree ?was ?preliminarily constructed.?By?collecting?relevant?data?of?Hebei?Province,?the?correlation?analysis?and?screening?of?the?primary evaluation?indexes?were?carried?out?to?determine?the?evaluation?system?of?water?resources?security?degree.?The TOPSIS?model?combined?with?the?variation?coefficient?method?and?the?rank?sum?ratio?method?was?introduced?to comprehensively ?evaluate ?the ?water ?resources ?security ?degree ?of ?Hebei ?Province ?from ?2001 ?to ?2020, ?and ?the evaluation?results?were?diagnosed?with?obstacle?factors. ??????The?results?showed?that?the?relative?closeness?of?water?resources?security?degree?in?Hebei?Province?increased from?0.217?to?0.745?from?2001?to?2020,?from?extremely?low?to?high,?and?reached?a?medium?level?as?a?whole.?From 2001?to?2007,?the?level?of?water?resources?security?degree?was?grade?V.?From?2008?to?2010,?the?level?of?water resources?security?degree?reached?grade?IV.From?2011?to?2012,?the?level?of?water?resources?security?reached?grade III.From?the?end?of?2014,?the?progress?has?been?increasing?year?by?year,?which?was?closely?related?to?the?increase?of the?proportion?of?cross-basin?water?supply?in?the?response?subsystem.?From?the?weight?calculation?results,?it?was concluded?that?the?response?subsystem?was?the?main?subsystem?affecting?the?water?resources?security?degree?of Hebei ?Province, ?and ?the ?obstacle ?degree ?of ?the ?proportion ?index ?of ?inter-basin ?water ?supply ?was ?the ?highest, indicating ?that ?the ?proportion ?of ?inter-basin ?water ?supply ?was ?the ?primary ?obstacle ?factor ?affecting ?the ?water resources?security?degree. ??????In?order?to?further?improve?the?situation?of?water?resources?security?degree?in?Hebei?Province,?it?was?necessary to?optimize?the?allocation?of?water?resources?and?alleviate?the?pressure?of?water?resources.?The?biological?treatment and?physical?and?chemical?treatment?technology,?are?adopted,?the?process?flow,?is?optimize?the?economic?structure and?industrial?structure,?are?adjusted,?and?improve?labor?productivity?is?improved?;?it?was?necessary?to?advocate residents?to?improve?their?lifestyles?and?reduce?the?use?of?cleaners?and?detergents?containing?chemical?substances.?At the?same?time,?it?was?necessary?to?improve?the?efficiency?of?water?resources?utilization?and?promote?the?circular economy ?model. ?The ?DPSIR-game ?theory ?combined ?weighting ?TOPSIS ?model ?had ?good ?objectivity ?and applicability ?for ?the ?evaluation ?of ?water ?resources ?security ?evolution, ?and ?was ?of ?great ?significance ?to ?the development ?of ?economy, ?society ?and ?ecological ?environment ?in ?the ?region. ?The ?research ?results ?provided ?a reference?for?the?rational?development,?utilization?and?management?of?water?resources?in?Hebei?Province?in?the future.
Hebei?Province?is?an?important?ecological?barrier?in?northern?China?and?an?important?support?for?the coordinated?development?of?Beijing,?Tianjin?and?Hebei.?However,?its?water?resources?problem?was?prominent,?the per?capita?possession?was?low,?the?spatial?and?temporal?distribution?was?uneven,?and?the?contradiction?between supply?and?demand?of?water?resources?was?increasing.?With?the?continuous?development?of?social?economy,?the intensity?and?pressure?of?water?resources?development?and?utilization?were?increasing?year?by?year,?and?the?problem of?water?ecological?environment?was?becoming?more?and?more?serious.?In?order?to?objectively?and?effectively evaluate?the?water?resources?security?degree?of?Hebei?Province,?ensure?that?the?natural?circulation?system?of?water resources ?can ?meet ?the ?natural ?guarantee ?function ?of ?national ?or ?regional ?development ?needs ?without ?being destroyed?or?threatened?by?people. ??????Based ?on ?the ?DPSIR ?model, ?the ?evaluation ?system ?of ?water ?resources ?security ?degree ?was ?preliminarily constructed.?By?collecting?relevant?data?of?Hebei?Province,?the?correlation?analysis?and?screening?of?the?primary evaluation?indexes?were?carried?out?to?determine?the?evaluation?system?of?water?resources?security?degree.?The TOPSIS?model?combined?with?the?variation?coefficient?method?and?the?rank?sum?ratio?method?was?introduced?to comprehensively ?evaluate ?the ?water ?resources ?security ?degree ?of ?Hebei ?Province ?from ?2001 ?to ?2020, ?and ?the evaluation?results?were?diagnosed?with?obstacle?factors. ??????The?results?showed?that?the?relative?closeness?of?water?resources?security?degree?in?Hebei?Province?increased from?0.217?to?0.745?from?2001?to?2020,?from?extremely?low?to?high,?and?reached?a?medium?level?as?a?whole.?From 2001?to?2007,?the?level?of?water?resources?security?degree?was?grade?V.?From?2008?to?2010,?the?level?of?water resources?security?degree?reached?grade?IV.From?2011?to?2012,?the?level?of?water?resources?security?reached?grade III.From?the?end?of?2014,?the?progress?has?been?increasing?year?by?year,?which?was?closely?related?to?the?increase?of the?proportion?of?cross-basin?water?supply?in?the?response?subsystem.?From?the?weight?calculation?results,?it?was concluded?that?the?response?subsystem?was?the?main?subsystem?affecting?the?water?resources?security?degree?of Hebei ?Province, ?and ?the ?obstacle ?degree ?of ?the ?proportion ?index ?of ?inter-basin ?water ?supply ?was ?the ?highest, indicating ?that ?the ?proportion ?of ?inter-basin ?water ?supply ?was ?the ?primary ?obstacle ?factor ?affecting ?the ?water resources?security?degree. ??????In?order?to?further?improve?the?situation?of?water?resources?security?degree?in?Hebei?Province,?it?was?necessary to?optimize?the?allocation?of?water?resources?and?alleviate?the?pressure?of?water?resources.?The?biological?treatment and?physical?and?chemical?treatment?technology,?are?adopted,?the?process?flow,?is?optimize?the?economic?structure and?industrial?structure,?are?adjusted,?and?improve?labor?productivity?is?improved?;?it?was?necessary?to?advocate residents?to?improve?their?lifestyles?and?reduce?the?use?of?cleaners?and?detergents?containing?chemical?substances.?At the?same?time,?it?was?necessary?to?improve?the?efficiency?of?water?resources?utilization?and?promote?the?circular economy ?model. ?The ?DPSIR-game ?theory ?combined ?weighting ?TOPSIS ?model ?had ?good ?objectivity ?and applicability ?for ?the ?evaluation ?of ?water ?resources ?security ?evolution, ?and ?was ?of ?great ?significance ?to ?the development ?of ?economy, ?society ?and ?ecological ?environment ?in ?the ?region. ?The ?research ?results ?provided ?a reference?for?the?rational?development,?utilization?and?management?of?water?resources?in?Hebei?Province?in?the future.
Abstract:
Flood?forecasting?and?prediction?are?integral?components?of?non-structural?flood?management?measures. Methods ?for ?flood ?forecasting ?and ?prediction ?can ?generally ?be ?classified ?into ?two ?categories: ?process-driven approaches?(hydrological?models)?and?data-driven?approaches.?Traditionally,?the?focus?has?been?on?process-driven approaches,?but?with?the?accumulation?of?hydrological?data?and?advancements?in?big?data?analytics,?data-driven approaches?have?gained?increasing?attention.?In?particular,?the?application?of?artificial?intelligence?technology?in?the water?industry?has?led?to?the?emergence?of?hydrological?data?mining-based?forecasting?and?prediction?methods?as?a research?hotspot.?Conducting?hydrological?knowledge?mining?and?prediction?based?on?the?principle?of?similarity?has become?an?important?research?direction,?offering?a?new?technical?means?to?uncover?hidden?patterns?within?rainfall, floods,?and?watershed?surface?information.?This?approach?also?promotes?the?automation?and?intelligence?of?water resources ?data ?processing, ?assisting ?in ?improving ?the ?accuracy ?of ?flood ?forecasting ?and ?prediction, ?thereby facilitating?the?modernization?and?precision?of?the?water?industry. ??????In?theory,?the?longer?the?series?of?hydrological?data,?the?more?torrential?rain-induced?flood?knowledge?can?be extracted.?However,?hydrological?data?series?in?a?changing?environment?often?exhibit?inconsistencies,?which?affect the ?accuracy ?of ?flood ?forecasting ?and ?prediction ?based ?on ?torrential ?rain-induced ?flood ?knowledge. ?Currently, research?on?historical?similar?torrential?rain-induced?flood?knowledge?considering?inconsistencies?in?guiding?real- time?flood?forecasting?is?relatively?limited.?In?this?context,?a?methodology?based?on?the?knowledge?of?torrential?rain- induced?floods?for?real-time?flood?forecasting?and?prediction?is?proposed.?The?proposed?method?focuses?on?historical records?of?typical?torrential?rain-induced?floods?and?extracts?rainfall?feature?indicators,?such?as?the?position?of?the rainstorm?center,?antecedent?precipitation,?total?average?rainfall,?and?rainfall?processes.?Multiple?feature?indicators are?simultaneously?assessed?for?their?similarity?using?criteria?such?as?Euclidean?distance.?By?inferring?historical typical ?floods ?based ?on ?similarity ?knowledge ?and ?incorporating ?the ?"rainfall-peak ?flow" ?or ?"rainfall-runoff" relationship ?before ?and ?after ?the ?change, ?a ?combined ?"peak-flow" ?correction ?approach ?is ?applied ?to ?ensure consistency. ?Real-time ?rolling ?extrapolation ?is ?then ?performed ?to ?estimate ?future ?flood ?processes, ?forming ?a comprehensive?"multi-feature?indicator?extraction-historical?torrential?rain-induced?flood?similarity?determination- real-time?flood?correction?and?extrapolation"?technique. ??????The?application?results?at?the?Mengyin?Station?on?the?Yi?River?demonstrate?the?effectiveness?of?the?proposed methodology.?For?any?given?torrential?rain-induced?flood?event,?the?most?similar?historical?flood?event?can?be accurately?identified?through?multiple?feature?indicators,?ensuring?the?theoretical?correctness?of?the?technique.?By considering?the?most?identified?similar?flood?event?and?applying?suitable?corrections?to?ensure?consistency,?the extrapolation ?and ?prediction ?of ?future ?flood ?processes ?significantly ?improve ?the ?accuracy ?of ?real-time ?flood forecasting?compared?to?the?direct?application?of?similar?flood?processes. ??????In?summary,?the?suggested?methodology,?grounded?in?torrential?rain-induced?flood?knowledge,?introduces?an effective?avenue?for?real-time?flood?forecasting?and?prediction.?By?extracting?multiple?feature?indicators,?evaluating their?similarity,?and?incorporating?correction?and?extrapolation?steps,?it?enables?accurate?identification?of?similar historical ?flood ?events ?and ?enhances ?the ?precision ?of ?real-time ?flood ?forecasting. ?This ?study ?contributes ?to ?the progression?of?flood?management?and?establishes?the?groundwork?for?further?research?aimed?at?enhancing?flood forecasting?accuracy?and?propelling?the?modernization?of?the?water?industry.
Flood?forecasting?and?prediction?are?integral?components?of?non-structural?flood?management?measures. Methods ?for ?flood ?forecasting ?and ?prediction ?can ?generally ?be ?classified ?into ?two ?categories: ?process-driven approaches?(hydrological?models)?and?data-driven?approaches.?Traditionally,?the?focus?has?been?on?process-driven approaches,?but?with?the?accumulation?of?hydrological?data?and?advancements?in?big?data?analytics,?data-driven approaches?have?gained?increasing?attention.?In?particular,?the?application?of?artificial?intelligence?technology?in?the water?industry?has?led?to?the?emergence?of?hydrological?data?mining-based?forecasting?and?prediction?methods?as?a research?hotspot.?Conducting?hydrological?knowledge?mining?and?prediction?based?on?the?principle?of?similarity?has become?an?important?research?direction,?offering?a?new?technical?means?to?uncover?hidden?patterns?within?rainfall, floods,?and?watershed?surface?information.?This?approach?also?promotes?the?automation?and?intelligence?of?water resources ?data ?processing, ?assisting ?in ?improving ?the ?accuracy ?of ?flood ?forecasting ?and ?prediction, ?thereby facilitating?the?modernization?and?precision?of?the?water?industry. ??????In?theory,?the?longer?the?series?of?hydrological?data,?the?more?torrential?rain-induced?flood?knowledge?can?be extracted.?However,?hydrological?data?series?in?a?changing?environment?often?exhibit?inconsistencies,?which?affect the ?accuracy ?of ?flood ?forecasting ?and ?prediction ?based ?on ?torrential ?rain-induced ?flood ?knowledge. ?Currently, research?on?historical?similar?torrential?rain-induced?flood?knowledge?considering?inconsistencies?in?guiding?real- time?flood?forecasting?is?relatively?limited.?In?this?context,?a?methodology?based?on?the?knowledge?of?torrential?rain- induced?floods?for?real-time?flood?forecasting?and?prediction?is?proposed.?The?proposed?method?focuses?on?historical records?of?typical?torrential?rain-induced?floods?and?extracts?rainfall?feature?indicators,?such?as?the?position?of?the rainstorm?center,?antecedent?precipitation,?total?average?rainfall,?and?rainfall?processes.?Multiple?feature?indicators are?simultaneously?assessed?for?their?similarity?using?criteria?such?as?Euclidean?distance.?By?inferring?historical typical ?floods ?based ?on ?similarity ?knowledge ?and ?incorporating ?the ?"rainfall-peak ?flow" ?or ?"rainfall-runoff" relationship ?before ?and ?after ?the ?change, ?a ?combined ?"peak-flow" ?correction ?approach ?is ?applied ?to ?ensure consistency. ?Real-time ?rolling ?extrapolation ?is ?then ?performed ?to ?estimate ?future ?flood ?processes, ?forming ?a comprehensive?"multi-feature?indicator?extraction-historical?torrential?rain-induced?flood?similarity?determination- real-time?flood?correction?and?extrapolation"?technique. ??????The?application?results?at?the?Mengyin?Station?on?the?Yi?River?demonstrate?the?effectiveness?of?the?proposed methodology.?For?any?given?torrential?rain-induced?flood?event,?the?most?similar?historical?flood?event?can?be accurately?identified?through?multiple?feature?indicators,?ensuring?the?theoretical?correctness?of?the?technique.?By considering?the?most?identified?similar?flood?event?and?applying?suitable?corrections?to?ensure?consistency,?the extrapolation ?and ?prediction ?of ?future ?flood ?processes ?significantly ?improve ?the ?accuracy ?of ?real-time ?flood forecasting?compared?to?the?direct?application?of?similar?flood?processes. ??????In?summary,?the?suggested?methodology,?grounded?in?torrential?rain-induced?flood?knowledge,?introduces?an effective?avenue?for?real-time?flood?forecasting?and?prediction.?By?extracting?multiple?feature?indicators,?evaluating their?similarity,?and?incorporating?correction?and?extrapolation?steps,?it?enables?accurate?identification?of?similar historical ?flood ?events ?and ?enhances ?the ?precision ?of ?real-time ?flood ?forecasting. ?This ?study ?contributes ?to ?the progression?of?flood?management?and?establishes?the?groundwork?for?further?research?aimed?at?enhancing?flood forecasting?accuracy?and?propelling?the?modernization?of?the?water?industry.
Abstract:
In ?the ?context ?of ?global ?climate ?change, ?greenhouse ?gas ?emissions ?from ?water ?projects ?are ?received increasing?attention.?The?impoundment?of?water?projects?submerges?soil?and?vegetation,?causing?the?degradation?of the?inner?organic?matter?to?produce?greenhouse?gases?(CO2,?CH4,?N2O)?and?discharge?them?into?the?atmosphere.?The drawdown?area?which?is?repeatedly?flooded?and?exposed?affected?by?the?regulation?of?water?projects?is?also?a?"hot spot"?for?producing?greenhouse?gases,?while?the?organic?carbon?buried?in?the?sediment?of?water?bodies?can?store atmospheric?CO2?thus?forming?carbon?sinks?in?the?short?or?long?term.?The?assessment?of?greenhouse?gas?flux?of water?projects?is?a?research?hotspot,?and?the?existing?monitored?data?can?be?used?for?research. ??????The?middle?and?lower?reaches?of?the?Hanjiang?River?are?important?ecological?and?economic?zones,?and?the development?of?society?has?damaged?the?health?of?the?rivers?in?this?area,?for?example?more?than?ten?algal?bloom outbreaks?have?occurred?so?far,?which?is?not?conducive?to?the?high-quality?development?of?the?basin.?A?rational operation ?of ?water ?projects ?is ?beneficial ?for ?alleviating ?algal ?bloom ?outbreaks ?and ?reducing ?greenhouse ?gas emissions.?In?order?to?effectively?improve?the?ecological?environment?and?ensure?high-quality?development?of?the watershed,?multi-objective?optimization?operation?research?is?always?carried?out?to?explore?the?optimal?operation mode ?of ?water ?projects. ?However, ?most ?of ?the ?existing ?researches ?focused ?on ?ecological ?indicators ?such ?as ecological?water?demand,?ecological?flow?change?degree,?fish?habitat,?and?algal?bloom?prevention?and?control, lacking ?the ?consideration ?of ?greenhouse ?gas ?emissions. ?In ?this ?case ?a ?multi-objective ?optimization ?model ?that comprehensively?considered?power?generation,?algal?bloom?prevention?and?control,?and?greenhouse?gas?emission control?was?established?to?explore?the?optimal?operation?mode?of?water?projects. ??????To ?solve ?the ?multi-objective ?problems, ?more ?and ?more ?researchers ?are ?using ?evolutionary ?optimization algorithms,?among?which?the?non-dominated?sorting?genetic?algorithm?(NSGA-II)?with?elite?strategy?is?the?most representative,?which?can?reduce?the?computational?complexity?of?non-dominated?sorting?methods,?has?advantages such?as?fast?running?speed?and?good?convergence?of?solution?sets,?and?has?been?widely?used?in?the?field?of?multi- objective?optimization?of?reservoir?operation.?Therefore,?the?NSGA-II?algorithm?was?used?to?solve?the?proposed model. ??????The?results?show?that?the?objective?of?greenhouse?gas?emission?control?was?in?a?competitive?relationship?with both?the?objective?of?power?generation?and?algal?bloom?prevention?and?control.?Compared?with?the?conventional operation?scheme,?the?optimal?operation?schemes?can?achieve?improvement?in?some?indicators.?Among?the?three optimal?operation?schemes,?the?compromised?scheme?can?achieve?improvement?of?all?the?indicators,?indicating?the effectiveness?of?the?proposed?model.?The?analysis?of?the?operation?process?during?typical?events?reveals?a?close relationship?between?greenhouse?gas?emissions?and?water?level?fluctuations. ??????Using?the?established?model,?the?net?greenhouse?gas?emissions?of?water?projects?during?the?operation?period were?estimated,?and?an?optimal?operation?scheme?which?can?achieve?better?benefits?compared?to?the?conventional operation?scheme?was?found.?The?results?can?provide?technical?support?for?achieving?the?optimal?operation?of?water projects,?reducing?greenhouse?gas?emissions,?and?repairing?the?ecological?environment?of?rivers.
In ?the ?context ?of ?global ?climate ?change, ?greenhouse ?gas ?emissions ?from ?water ?projects ?are ?received increasing?attention.?The?impoundment?of?water?projects?submerges?soil?and?vegetation,?causing?the?degradation?of the?inner?organic?matter?to?produce?greenhouse?gases?(CO2,?CH4,?N2O)?and?discharge?them?into?the?atmosphere.?The drawdown?area?which?is?repeatedly?flooded?and?exposed?affected?by?the?regulation?of?water?projects?is?also?a?"hot spot"?for?producing?greenhouse?gases,?while?the?organic?carbon?buried?in?the?sediment?of?water?bodies?can?store atmospheric?CO2?thus?forming?carbon?sinks?in?the?short?or?long?term.?The?assessment?of?greenhouse?gas?flux?of water?projects?is?a?research?hotspot,?and?the?existing?monitored?data?can?be?used?for?research. ??????The?middle?and?lower?reaches?of?the?Hanjiang?River?are?important?ecological?and?economic?zones,?and?the development?of?society?has?damaged?the?health?of?the?rivers?in?this?area,?for?example?more?than?ten?algal?bloom outbreaks?have?occurred?so?far,?which?is?not?conducive?to?the?high-quality?development?of?the?basin.?A?rational operation ?of ?water ?projects ?is ?beneficial ?for ?alleviating ?algal ?bloom ?outbreaks ?and ?reducing ?greenhouse ?gas emissions.?In?order?to?effectively?improve?the?ecological?environment?and?ensure?high-quality?development?of?the watershed,?multi-objective?optimization?operation?research?is?always?carried?out?to?explore?the?optimal?operation mode ?of ?water ?projects. ?However, ?most ?of ?the ?existing ?researches ?focused ?on ?ecological ?indicators ?such ?as ecological?water?demand,?ecological?flow?change?degree,?fish?habitat,?and?algal?bloom?prevention?and?control, lacking ?the ?consideration ?of ?greenhouse ?gas ?emissions. ?In ?this ?case ?a ?multi-objective ?optimization ?model ?that comprehensively?considered?power?generation,?algal?bloom?prevention?and?control,?and?greenhouse?gas?emission control?was?established?to?explore?the?optimal?operation?mode?of?water?projects. ??????To ?solve ?the ?multi-objective ?problems, ?more ?and ?more ?researchers ?are ?using ?evolutionary ?optimization algorithms,?among?which?the?non-dominated?sorting?genetic?algorithm?(NSGA-II)?with?elite?strategy?is?the?most representative,?which?can?reduce?the?computational?complexity?of?non-dominated?sorting?methods,?has?advantages such?as?fast?running?speed?and?good?convergence?of?solution?sets,?and?has?been?widely?used?in?the?field?of?multi- objective?optimization?of?reservoir?operation.?Therefore,?the?NSGA-II?algorithm?was?used?to?solve?the?proposed model. ??????The?results?show?that?the?objective?of?greenhouse?gas?emission?control?was?in?a?competitive?relationship?with both?the?objective?of?power?generation?and?algal?bloom?prevention?and?control.?Compared?with?the?conventional operation?scheme,?the?optimal?operation?schemes?can?achieve?improvement?in?some?indicators.?Among?the?three optimal?operation?schemes,?the?compromised?scheme?can?achieve?improvement?of?all?the?indicators,?indicating?the effectiveness?of?the?proposed?model.?The?analysis?of?the?operation?process?during?typical?events?reveals?a?close relationship?between?greenhouse?gas?emissions?and?water?level?fluctuations. ??????Using?the?established?model,?the?net?greenhouse?gas?emissions?of?water?projects?during?the?operation?period were?estimated,?and?an?optimal?operation?scheme?which?can?achieve?better?benefits?compared?to?the?conventional operation?scheme?was?found.?The?results?can?provide?technical?support?for?achieving?the?optimal?operation?of?water projects,?reducing?greenhouse?gas?emissions,?and?repairing?the?ecological?environment?of?rivers.
ZHAO?Lefan
1, 2, 3，YANG?Zhenjing
2, 3，MA?Rong
2, 3，NING?Kai
2, 3，CHEN?Peng
2, 3, 4，WU?Jun
2, 3, 5，LI?Yang
6
Abstract:
As?an?integral?part?of?the?terrestrial?hydrosphere,?lakes?play?an?indispensable?role?in?regional?water?cycle, water?balance?and?water?resources?regulation.?Due?to?the?different?climatic?conditions?and?human?activities,?the causes?of?lake?shrinkage?in?different?time?and?space?are?significantly?different.?The?Hunshandake?Sandy?Land?is located?in?the?eastern?part?of?Inner?Mongolia.?Due?to?its?unique?geographical?pattern?and?climatic?characteristics,?the predecessors?have?carried?out?a?lot?of?research?on?this?area.?However,?most?of?the?previous?studies?focused?on climate?change?and?ecological?stability,?and?only?a?small?amount?of?research?focused?on?lake?area?and?water?volume. And?the?studies?are?mainly?concentrated?before?2015,?and?there?is?a?lack?of?research?on?the?recent?Hunshandake?in the?current?new?state.?In?particular,?there?is?a?lack?of?research?on?the?changes?of?water?balance?factors?based?on?the water ?balance ?model ?and ?the ?quantitative ?analysis ?of ?human ?activities ?and ?climate ?change ?on ?lake ?evolution. Therefore,?it?is?of?great?significance?to?reveal?the?mechanism?of?shrinkage?and?degradation?of?lakes?in?Hunshandake Sandy?Land?of?Inner?Mongolia?Plateau?for?the?protection?and?restoration?of?lakes?in?Hunshandake?Sandy?Land. ??????Based?on?Landsat?TM?/?ETM?+,?the?lake?area?of?Junma?Lake?from?1991?to?2021?was?extracted.?Combined?with DEM?data?and?field?elevation?point?test,?the?water?depth-area-volume?curve?of?Junma?Lake?was?established?to calculate?the?lake?water?volume.?Based?on?the?meteorological?data,?the?water?balance?model?of?Junma?Lake?from 1991 ?to ?2021 ?was ?established. ?The ?variation ?characteristics ?of ?water ?balance ?factors ?such ?as ?precipitation, evaporation?and?runoff?are?quantitatively?analyzed,?the?interaction?between?income?items?and?expenditure?items?and their?impact?on?lake?water?volume?changes?is?analyzed,?the?impact?of?climate?change?and?human?activities?on?lake water?volume?changes?at?different?stages?is?analyzed,?and?the?main?control?factors?of?lake?water?volume?changes?at different?stages?are?determined.?The?research?results?can?provide?basis?and?support?for?regional?lake?evolution?and ecological?protection. ??????The?results?show?that?the?lake?water?volume?decreases?from?1?450?×?104?m3?in?1991?to?380?×?104?m3?in?2021, with?an?average?annual?change?rate?of??34?×?104?m3/a.?The?regional?precipitation,?evaporation?and?groundwater recharge?all?show?a?decreasing?trend,?with?an?average?annual?change?rate?of??10?×?104?m3/a,??7?×?104?m3/a?and??5?× 104?m3/a,?respectively.?Before?2006,?the?lake?recharge?and?discharge?showed?a?weak?negative?equilibrium;?after 2006,?due?to?the?significant?reduction?of?groundwater?recharge,?the?negative?balance?of?lake?water?increased?and?the shrinkage?rate?accelerated. ??????The?results?show?that:?before?2006,?climate?warming?and?drying?was?the?main?factor?leading?to?lake?shrinkage; after?2006,?the?large-scale?exploitation?of?groundwater?resources?affected?the?lake?recharge,?and?human?activities became ?the ?main ?controlling ?factor ?of ?lake ?shrinkage. ?Rational ?development ?and ?utilization ?of ?groundwater resources?and?improvement?of?water?resources?utilization?efficiency?can?alleviate?the?shrinkage?and?degradation?of lake?wetlands?in?Hunshandake?Sandy?Land?to?a?certain?extent.
As?an?integral?part?of?the?terrestrial?hydrosphere,?lakes?play?an?indispensable?role?in?regional?water?cycle, water?balance?and?water?resources?regulation.?Due?to?the?different?climatic?conditions?and?human?activities,?the causes?of?lake?shrinkage?in?different?time?and?space?are?significantly?different.?The?Hunshandake?Sandy?Land?is located?in?the?eastern?part?of?Inner?Mongolia.?Due?to?its?unique?geographical?pattern?and?climatic?characteristics,?the predecessors?have?carried?out?a?lot?of?research?on?this?area.?However,?most?of?the?previous?studies?focused?on climate?change?and?ecological?stability,?and?only?a?small?amount?of?research?focused?on?lake?area?and?water?volume. And?the?studies?are?mainly?concentrated?before?2015,?and?there?is?a?lack?of?research?on?the?recent?Hunshandake?in the?current?new?state.?In?particular,?there?is?a?lack?of?research?on?the?changes?of?water?balance?factors?based?on?the water ?balance ?model ?and ?the ?quantitative ?analysis ?of ?human ?activities ?and ?climate ?change ?on ?lake ?evolution. Therefore,?it?is?of?great?significance?to?reveal?the?mechanism?of?shrinkage?and?degradation?of?lakes?in?Hunshandake Sandy?Land?of?Inner?Mongolia?Plateau?for?the?protection?and?restoration?of?lakes?in?Hunshandake?Sandy?Land. ??????Based?on?Landsat?TM?/?ETM?+,?the?lake?area?of?Junma?Lake?from?1991?to?2021?was?extracted.?Combined?with DEM?data?and?field?elevation?point?test,?the?water?depth-area-volume?curve?of?Junma?Lake?was?established?to calculate?the?lake?water?volume.?Based?on?the?meteorological?data,?the?water?balance?model?of?Junma?Lake?from 1991 ?to ?2021 ?was ?established. ?The ?variation ?characteristics ?of ?water ?balance ?factors ?such ?as ?precipitation, evaporation?and?runoff?are?quantitatively?analyzed,?the?interaction?between?income?items?and?expenditure?items?and their?impact?on?lake?water?volume?changes?is?analyzed,?the?impact?of?climate?change?and?human?activities?on?lake water?volume?changes?at?different?stages?is?analyzed,?and?the?main?control?factors?of?lake?water?volume?changes?at different?stages?are?determined.?The?research?results?can?provide?basis?and?support?for?regional?lake?evolution?and ecological?protection. ??????The?results?show?that?the?lake?water?volume?decreases?from?1?450?×?104?m3?in?1991?to?380?×?104?m3?in?2021, with?an?average?annual?change?rate?of??34?×?104?m3/a.?The?regional?precipitation,?evaporation?and?groundwater recharge?all?show?a?decreasing?trend,?with?an?average?annual?change?rate?of??10?×?104?m3/a,??7?×?104?m3/a?and??5?× 104?m3/a,?respectively.?Before?2006,?the?lake?recharge?and?discharge?showed?a?weak?negative?equilibrium;?after 2006,?due?to?the?significant?reduction?of?groundwater?recharge,?the?negative?balance?of?lake?water?increased?and?the shrinkage?rate?accelerated. ??????The?results?show?that:?before?2006,?climate?warming?and?drying?was?the?main?factor?leading?to?lake?shrinkage; after?2006,?the?large-scale?exploitation?of?groundwater?resources?affected?the?lake?recharge,?and?human?activities became ?the ?main ?controlling ?factor ?of ?lake ?shrinkage. ?Rational ?development ?and ?utilization ?of ?groundwater resources?and?improvement?of?water?resources?utilization?efficiency?can?alleviate?the?shrinkage?and?degradation?of lake?wetlands?in?Hunshandake?Sandy?Land?to?a?certain?extent.
Abstract:
The?construction?of?a?regional?water?network?is?a?crucial?measure?to?address?complex?water?problems such?as?the?uneven?spatial?and?temporal?distribution?of?water?resources,?while?to?achieve?the?goal?of?ecological protection ?and ?high-quality ?development. ?The ?water ?network, ?mainly ?consisting ?of ?water ?transfer ?and ?storage projects,?has?changed?the?pattern?of?water?resources?and?the?eco-hydrological?processes?of?rivers,?and?has?adverse impacts ?on ?the ?ecological ?environment. ?The ?Datong ?River ?basin ?is ?abundant ?in ?water ?resources ?and ?has ?great potential?for?hydropower.?The?three?major?water?transfer?projects?(from?Datong?River?to?Qinwangchuan?basin,?from Datong?River?to?Jinchang?City,?and?from?Datong?River?to?Huangshui?River?basin)?in?this?region?have?made?great contributions?to?the?economic?and?social?development?of?the?Xining-Lanzhou?City?cluster.?Given?that?the?Datong River?basin?includes?environmentally?sensitive?areas?such?as?the?upper?reaches?of?the?Yellow?River?Reserve?and?the Qilian?Mountain?National?Park,?ensuring?ecological?safety?is?important.?Unfortunately,?some?early?projects?failed?to adequately?consider?environmental?protection?requirements?at?the?planning?stage,?resulting?in?significant?changes?in river?hydrology,?including?reduced?river?flows,?deteriorating?water?quality,?and?declining?biodiversity. ??????On?the?basis?of?comprehensive?understanding?of?the?eco-hydrological?conditions,?the?characteristics?of?water transfer?and?hydropower?projects,?and?the?current?situation?of?water?resources?utilization?in?the?Datong?River?basin, three?key?control?sections?(Qingshizui,?Tiantang,?and?Xiangtang)?were?determined.?Nine?widely?used?hydrologically- based?methods?were?employed?to?calculate?12?ecological?flow?processes?at?the?three?sections,?which?were?considered in ?the ?water ?resource ?allocation ?of ?the ?Datong ?River ?basin. ?Furthermore, ?the ?Water-Energy-Ecosystem ?(WEE) Nexus?model,?which?was?developed?based?on?multi-objective?and?nonlinear?programming,?was?used?to?optimize?and compare?the?operations?of?different?water?diversion?and?storage?projects?as?well?as?the?corresponding?ecological flow?guarantee?rate?under?12?different?ecological?flow?processes,?with?the?past?60-year?hydrological?series?as?the model?input. ??????The?following?conclusions?can?be?drawn.?(1)?The?ecological?flows?were?increased?from?upstream?to?downstream along?the?Datong?River?(Qingshizui
The?construction?of?a?regional?water?network?is?a?crucial?measure?to?address?complex?water?problems such?as?the?uneven?spatial?and?temporal?distribution?of?water?resources,?while?to?achieve?the?goal?of?ecological protection ?and ?high-quality ?development. ?The ?water ?network, ?mainly ?consisting ?of ?water ?transfer ?and ?storage projects,?has?changed?the?pattern?of?water?resources?and?the?eco-hydrological?processes?of?rivers,?and?has?adverse impacts ?on ?the ?ecological ?environment. ?The ?Datong ?River ?basin ?is ?abundant ?in ?water ?resources ?and ?has ?great potential?for?hydropower.?The?three?major?water?transfer?projects?(from?Datong?River?to?Qinwangchuan?basin,?from Datong?River?to?Jinchang?City,?and?from?Datong?River?to?Huangshui?River?basin)?in?this?region?have?made?great contributions?to?the?economic?and?social?development?of?the?Xining-Lanzhou?City?cluster.?Given?that?the?Datong River?basin?includes?environmentally?sensitive?areas?such?as?the?upper?reaches?of?the?Yellow?River?Reserve?and?the Qilian?Mountain?National?Park,?ensuring?ecological?safety?is?important.?Unfortunately,?some?early?projects?failed?to adequately?consider?environmental?protection?requirements?at?the?planning?stage,?resulting?in?significant?changes?in river?hydrology,?including?reduced?river?flows,?deteriorating?water?quality,?and?declining?biodiversity. ??????On?the?basis?of?comprehensive?understanding?of?the?eco-hydrological?conditions,?the?characteristics?of?water transfer?and?hydropower?projects,?and?the?current?situation?of?water?resources?utilization?in?the?Datong?River?basin, three?key?control?sections?(Qingshizui,?Tiantang,?and?Xiangtang)?were?determined.?Nine?widely?used?hydrologically- based?methods?were?employed?to?calculate?12?ecological?flow?processes?at?the?three?sections,?which?were?considered in ?the ?water ?resource ?allocation ?of ?the ?Datong ?River ?basin. ?Furthermore, ?the ?Water-Energy-Ecosystem ?(WEE) Nexus?model,?which?was?developed?based?on?multi-objective?and?nonlinear?programming,?was?used?to?optimize?and compare?the?operations?of?different?water?diversion?and?storage?projects?as?well?as?the?corresponding?ecological flow?guarantee?rate?under?12?different?ecological?flow?processes,?with?the?past?60-year?hydrological?series?as?the model?input. ??????The?following?conclusions?can?be?drawn.?(1)?The?ecological?flows?were?increased?from?upstream?to?downstream along?the?Datong?River?(Qingshizui
Abstract:
To?investigate?the?effect?of?low?impact?development?(LID)?facilities?on?alleviating?urban?flood?disaster and?reducing?pollution?load,?four?kinds?of?LID?facilities?were?selected,?including?green?roof,?rainwater?garden, permeable?pavement?and?rainwater?tank.?By?constructing?the?SWMM?model,?the?catchment?surface?was?divided?into different ?partitions ?according ?to ?the ?actual ?terrain ?and ?pipe ?network ?direction. ?The ?influence ?of ?LID ?facility combination?on?runoff?control?and?rainwater?pollution?load?under?the?seven?layout?schemes?was?analyzed,?the?results showed?that?the?LID?facility?combination?could?effectively?reduce?the?runoff?and?rainwater?pollution?load?for?the seven?layout?schemes,?and?the?LID?facility?combination?has?a?better?control?effect?on?the?runoff?in?the?upstream?and midstream?areas.?Under?the?same?design?rainfall?return?period,?the?reduction?effect?of?each?layout?scheme?was?as follows: ?the ?whole ?area ?> ?upstream ?and ?midstream ?areas ?> ?midstream ?and ?downstream ?areas ?> ?upstream ?and downstream ?areas ?> ?downstream ?area ?> ?midstream ?area ?> ?upstream ?area. ?The ?runoff ?reduction ?rate ?in ?the downstream?area?was?5.19%?-?6.82%?higher?than?the?upstream?area,?the?upstream?and?midstream?areas?were?1.87%- 3.62%?higher?than?the?upstream?and?downstream?areas,?and?16.48%-18.97%?higher?than?the?downstream?area.?When the?whole?area?was?deployed,?it?was?29.60%-31.17%?higher?than?the?downstream?area?and?12.20%?-13.12%?higher than ?the ?upstream ?and ?midstream ?areas.Therefore, ?before ?the ?planning ?and ?construction ?of ?sponge ?city, ?it ?was suggested?that:?the?LID?facilities?should?be?set?up?on?demand?in?the?whole?area;?in?the?transformation?of?old residential?areas,?the?LID?facilities?could?be?emphatically?considered?in?the?upstream?and?midstream?areas.
To?investigate?the?effect?of?low?impact?development?(LID)?facilities?on?alleviating?urban?flood?disaster and?reducing?pollution?load,?four?kinds?of?LID?facilities?were?selected,?including?green?roof,?rainwater?garden, permeable?pavement?and?rainwater?tank.?By?constructing?the?SWMM?model,?the?catchment?surface?was?divided?into different ?partitions ?according ?to ?the ?actual ?terrain ?and ?pipe ?network ?direction. ?The ?influence ?of ?LID ?facility combination?on?runoff?control?and?rainwater?pollution?load?under?the?seven?layout?schemes?was?analyzed,?the?results showed?that?the?LID?facility?combination?could?effectively?reduce?the?runoff?and?rainwater?pollution?load?for?the seven?layout?schemes,?and?the?LID?facility?combination?has?a?better?control?effect?on?the?runoff?in?the?upstream?and midstream?areas.?Under?the?same?design?rainfall?return?period,?the?reduction?effect?of?each?layout?scheme?was?as follows: ?the ?whole ?area ?> ?upstream ?and ?midstream ?areas ?> ?midstream ?and ?downstream ?areas ?> ?upstream ?and downstream ?areas ?> ?downstream ?area ?> ?midstream ?area ?> ?upstream ?area. ?The ?runoff ?reduction ?rate ?in ?the downstream?area?was?5.19%?-?6.82%?higher?than?the?upstream?area,?the?upstream?and?midstream?areas?were?1.87%- 3.62%?higher?than?the?upstream?and?downstream?areas,?and?16.48%-18.97%?higher?than?the?downstream?area.?When the?whole?area?was?deployed,?it?was?29.60%-31.17%?higher?than?the?downstream?area?and?12.20%?-13.12%?higher than ?the ?upstream ?and ?midstream ?areas.Therefore, ?before ?the ?planning ?and ?construction ?of ?sponge ?city, ?it ?was suggested?that:?the?LID?facilities?should?be?set?up?on?demand?in?the?whole?area;?in?the?transformation?of?old residential?areas,?the?LID?facilities?could?be?emphatically?considered?in?the?upstream?and?midstream?areas.
Abstract:
The?prediction?of?reservoir?water?level?is?of?great?significance?in?the?daily?operation?and?management?of reservoir,?the?reinforcement?of?dam,?the?mitigation?of?flood?disaster,?and?the?protection?of?people's?life?and?property safety. ?However, ?with ?the ?change ?of ?global ?temperature, ?the ?frequency ?of ?extreme ?weather ?increases ?and ?the uncertainty?of?abnormal?rainfall?increases,?which?lead?to?the?lagging?of?reservoir?level?prediction?methods?relying?on traditional?engineering?hydrology.?Due?to?the?high?practicability?of?deep?learning?algorithms?used?in?various?fields, there?are?a?few?examples?of?domestic?and?foreign?scholars?using?artificial?intelligence?to?predict?water?levels.?In order?to?make?up?for?the?shortcomings?of?single?artificial?intelligence?model,?some?scholars?also?used?the?neural network?model?coupling?method?to?study?water?level?prediction,?and?a?small?number?of?scholars?input?a?single variable?to?predict?water?level.?The?above?research?shows?that?it?is?feasible?to?use?the?coupled?model?for?water?level prediction,?and?the?advantages?of?multiple?models?complement?each?other,?and?the?prediction?accuracy?is?improved to?different?degrees?compared?with?the?previous?single?model. ??????Considering?various?practical?factors,?the?monitoring?data?of?water?level?of?Siling?Reservoir?was?taken?as?an example?and?the?coupling?prediction?model?of?water?level?of?reservoir?was?put?forward?based?on?Embedding?GRU on?the?condition?that?there?was?only?a?single?characteristic?rainfall,?in?order?to?provide?a?reference?for?realizing?the high-precision?prediction?of?water?level?with?single?characteristics.?According?to?the?rainfall?scale?of?the?data?set?and the?largest?rainfall?in?the?history?of?Zhejiang?Province,?the?training?parameter?rainfall?scale?sets?of?the?Embedding stage ?is ?defined ?as ?{500,550,600,650,700,750} ?with ?the ?accuracy ?of ?mm×10 ?1. ?In ?order ?to ?study ?the ?optimal parameter?setting,?the?range?of?feature?dimension?setting?was?extended?to?{2,3,4,5,6}?on?the?premise?of?adopting?the control?variates.?The?ERMS?indicator?was?selected?for?this?experiment.?To?further?validate?the?predictive?performance and?generalization?ability?of?the?Embedding?GRU?model,?an?experiment?was?conducted?based?on?the?total?daily rainfall?to?predict?the?next?day's?reservoir?water?level.?The?comparison?algorithm?is?still?LSTM,?GRU,?and?BiGRU, with?a?total?of?1?826?sets?of?data?with?a?data?volume?of?5?years. ??????Compared?with?other?existing?artificial?intelligence?models?of?reservoir?water?level,?the?prediction?accuracy?is higher?and?the?scope?of?reservoir?is?wider.?In?the?comparative?experiment?of?predicting?the?next?hour's?water?level，the ?prediction ?ability ?of ?the ?four ?models ?was ?excellent, ?and ?they ?could ?fit ?the ?real ?water ?level ?data ?relatively accurately, ?which ?shows ?that ?the ?method ?of ?predicting ?the ?reservoir ?water ?level ?by ?deep ?learning ?algorithm ?is effective?and?feasible.?By?comparing?of?prediction?accuracy?of?four?models，the?experiment?proved?that?GRU algorithm?is?better?than?LSTM?in?prediction?effect,?and?the?embedding?method?can?further?effectively?reduce?the prediction?error?and?improve?the?prediction?accuracy?of?the?model. ??????It?is?the?Embedding?method?that?enlarges?the?features?between?rainfall?and?climate,?coupled?with?lightweight deep ?learning ?algorithm ?GRU ?to ?predict ?reservoir ?water ?level. ?Conclusions ?are ?as ?follows: ?(1) ?The ?prediction accuracy?of?the?Embedding?GRU?model?is?obviously?better?than?that?of?LSTM,?GRU,?BiGRU?and?other?single?deep learning?models.?(2)?Embedding?parameters?in?the?Embedding?GRU?model?shall?be?determined?by?comparative?test according?to?the?actual?data?set.?(3)?The?Embedding-GRU?model?has?excellent?performance?in?predicting?different period?of?multiple?times?within?7?days,?and?has?good?prediction?effect?and?generalization?ability,?which?fully?proves the?effectiveness?of?the?model.
The?prediction?of?reservoir?water?level?is?of?great?significance?in?the?daily?operation?and?management?of reservoir,?the?reinforcement?of?dam,?the?mitigation?of?flood?disaster,?and?the?protection?of?people's?life?and?property safety. ?However, ?with ?the ?change ?of ?global ?temperature, ?the ?frequency ?of ?extreme ?weather ?increases ?and ?the uncertainty?of?abnormal?rainfall?increases,?which?lead?to?the?lagging?of?reservoir?level?prediction?methods?relying?on traditional?engineering?hydrology.?Due?to?the?high?practicability?of?deep?learning?algorithms?used?in?various?fields, there?are?a?few?examples?of?domestic?and?foreign?scholars?using?artificial?intelligence?to?predict?water?levels.?In order?to?make?up?for?the?shortcomings?of?single?artificial?intelligence?model,?some?scholars?also?used?the?neural network?model?coupling?method?to?study?water?level?prediction,?and?a?small?number?of?scholars?input?a?single variable?to?predict?water?level.?The?above?research?shows?that?it?is?feasible?to?use?the?coupled?model?for?water?level prediction,?and?the?advantages?of?multiple?models?complement?each?other,?and?the?prediction?accuracy?is?improved to?different?degrees?compared?with?the?previous?single?model. ??????Considering?various?practical?factors,?the?monitoring?data?of?water?level?of?Siling?Reservoir?was?taken?as?an example?and?the?coupling?prediction?model?of?water?level?of?reservoir?was?put?forward?based?on?Embedding?GRU on?the?condition?that?there?was?only?a?single?characteristic?rainfall,?in?order?to?provide?a?reference?for?realizing?the high-precision?prediction?of?water?level?with?single?characteristics.?According?to?the?rainfall?scale?of?the?data?set?and the?largest?rainfall?in?the?history?of?Zhejiang?Province,?the?training?parameter?rainfall?scale?sets?of?the?Embedding stage ?is ?defined ?as ?{500,550,600,650,700,750} ?with ?the ?accuracy ?of ?mm×10 ?1. ?In ?order ?to ?study ?the ?optimal parameter?setting,?the?range?of?feature?dimension?setting?was?extended?to?{2,3,4,5,6}?on?the?premise?of?adopting?the control?variates.?The?ERMS?indicator?was?selected?for?this?experiment.?To?further?validate?the?predictive?performance and?generalization?ability?of?the?Embedding?GRU?model,?an?experiment?was?conducted?based?on?the?total?daily rainfall?to?predict?the?next?day's?reservoir?water?level.?The?comparison?algorithm?is?still?LSTM,?GRU,?and?BiGRU, with?a?total?of?1?826?sets?of?data?with?a?data?volume?of?5?years. ??????Compared?with?other?existing?artificial?intelligence?models?of?reservoir?water?level,?the?prediction?accuracy?is higher?and?the?scope?of?reservoir?is?wider.?In?the?comparative?experiment?of?predicting?the?next?hour's?water?level，the ?prediction ?ability ?of ?the ?four ?models ?was ?excellent, ?and ?they ?could ?fit ?the ?real ?water ?level ?data ?relatively accurately, ?which ?shows ?that ?the ?method ?of ?predicting ?the ?reservoir ?water ?level ?by ?deep ?learning ?algorithm ?is effective?and?feasible.?By?comparing?of?prediction?accuracy?of?four?models，the?experiment?proved?that?GRU algorithm?is?better?than?LSTM?in?prediction?effect,?and?the?embedding?method?can?further?effectively?reduce?the prediction?error?and?improve?the?prediction?accuracy?of?the?model. ??????It?is?the?Embedding?method?that?enlarges?the?features?between?rainfall?and?climate,?coupled?with?lightweight deep ?learning ?algorithm ?GRU ?to ?predict ?reservoir ?water ?level. ?Conclusions ?are ?as ?follows: ?(1) ?The ?prediction accuracy?of?the?Embedding?GRU?model?is?obviously?better?than?that?of?LSTM,?GRU,?BiGRU?and?other?single?deep learning?models.?(2)?Embedding?parameters?in?the?Embedding?GRU?model?shall?be?determined?by?comparative?test according?to?the?actual?data?set.?(3)?The?Embedding-GRU?model?has?excellent?performance?in?predicting?different period?of?multiple?times?within?7?days,?and?has?good?prediction?effect?and?generalization?ability,?which?fully?proves the?effectiveness?of?the?model.
Abstract:
Landscape?pattern?and?its?changes?are?of?great?importance?to?ecological?processes?and?security?in?basin?or region.?Liangzi?Lake?is?a?typical?well?protected?grassy?shallow?lake?in?China.?It?plays?important?roles?of?flood storage,?water?supply,?gene?pool,?freshwater?products?supply?and?so?on.?However,?due?to?continuous?reclamations for?farmlands?and?urbanization,?problems?related?to?water?area?shrinkage,?ecological?functional?degeneration?and landscape?fragmentation?are?raising?continuously.?Exploring?the?dynamic?changes?of?water?landscape?and?its?driving factors?from?the?perspective?of?landscape?pattern?in?whole?basin?would?obtain?in-deep?understanding?of?landscape characteristics?and?provide?scientific?references?of?Liangzi?Lake?protection?from?basin-wide?perspective. ??????The?methods?of?spatial?analysis,?landscape?metrics?analysis?and?biostatistical?analysis?are?applied?in?this?paper. Taking?water?landscape?as?the?research?object,?transition?matrix?analysis?is?used?to?describe?transitions?between water?area?and?other?types?of?land?use?during?study?phase.?Aggregation?feature?and?outlier?distribution?of?water?area are?studied?through?spatial?autocorrelation?analysis.?Landscape?metrics?analysis?is?used?to?express?the?features?of area, ?shape, ?aggregation ?and ?connectivity ?quantitively, ?while ?redundancy ?analysis ?is ?employed ?to ?seek ?for ?the driving?forces?of?dynamics?changes. ??????From ?2000 ?to ?2020, ?farmland ?area ?remained ?unchanged ?basically, ?while ?water ?area ?showed ?21%?decrease because?of?water?coverage?being?reclaimed?for?use?as?farmlands.?Urban?area?increased?by?more?than?4?times?by means?of?farmlands?transferred?into.?Water?area?clustered?spatially?with?a?weakening?trend.?The?distribution?of?High value?aggregation?and?Low?value?aggregation?in?water?area?got?more?fragmented,?and?the?area?of?Not?Significant type?increased?by?40%?in?last?decade.?PLAND?and?LPI?of?water?area?had?trend?of?increasing?followed?by?trend?of decreasing.?PD?dropped?gradually?with?an?obvious?decline?of?LSI.?There?were?significant?differences?between?upper and?lower?basin?-?PLAND?and?LPI?of?water?area?in?upper?area?were?about?16%?and?14%?respectively,?while?PLAND and?LPI?in?lower?area?decreased?by?more?than?40%?and?60%?respectively.?Shape?of?water?area?in?lower?area?was more?complicated?than?in?upper?area,?and?LSI?of?upper?and?lower?area?declined?by?32%?and?51%?respectively. Aggregation ?and ?connectivity ?in ?upper ?area ?were ?better ?than ?those ?in ?lower ?area. ?Variation ?partitioning ?of redundancy?analysis?shows?the?54.7%?changes?of?water?landscape?are?a?result?of?natural?and?artificial?factors,?of these ?influences, ?24.2%?of ?the ?changes ?coming ?from ?precipitation ?and ?temperature, ?while ?51.6%?coming ?from contribution?of?human?activities,?the?overlapping?part?is?21.0%. ??????From ?2000 ?to ?2020, ?surface ?area ?of ?water ?in ?Liangzi ?Lake ?has ?decreased ?by ?21%?because ?of ?agricultural reclamation ?directly, ?which ?then ?being ?reclaimed ?for ?urbanized ?purposes, ?leading ?to ?4-time ?area ?increases ?of artificial ?surfaces. ?Farmland ?area ?remains ?unchanged, ?water ?area ?decreased ?attributed ?to ?urbanized ?purposes indirectly.?There?is?a?steady?water?area?aggregation?in?whole?basin,?while?the?relevance?of?water?area?in?local?region are?becoming?decreased?or?disappeared.?Micro-water?body?are?disappearing?with?the?tendency?of?decreasing?of complexity?and?irregularity.?Water?area?distribution?tends?to?be?fragmented,?however?significant?differences?present between?upper?and?lower?basin?areas.?There?are?not?much?changes?of?spatial?distribution?of?water?landscape?in?upper basin?area,?but?in?lower?basin?area,?water?area?reduced?by?nearly?half.?Shoreline?tends?to?be?normalized?and?unified with?an?obvious?obstruction?and?cut?of?water?body.?54.7%?of?the?changes?of?water?landscape?are?the?result?of precipitation,?temperature,?population,?GDP?and?area?ratio?of?farmland?and?artificial?surface.?Human?activities?are the?main?factors,?whose?explanatory?power?are?twice?of?natural?factors.?Population?and?farmland?area?rate?make more?contributions?to?the?water?landscape?area,?meanwhile?GDP?and?urbanization?process?have?more?effects?on shape?complexity?and?connectivity.
Landscape?pattern?and?its?changes?are?of?great?importance?to?ecological?processes?and?security?in?basin?or region.?Liangzi?Lake?is?a?typical?well?protected?grassy?shallow?lake?in?China.?It?plays?important?roles?of?flood storage,?water?supply,?gene?pool,?freshwater?products?supply?and?so?on.?However,?due?to?continuous?reclamations for?farmlands?and?urbanization,?problems?related?to?water?area?shrinkage,?ecological?functional?degeneration?and landscape?fragmentation?are?raising?continuously.?Exploring?the?dynamic?changes?of?water?landscape?and?its?driving factors?from?the?perspective?of?landscape?pattern?in?whole?basin?would?obtain?in-deep?understanding?of?landscape characteristics?and?provide?scientific?references?of?Liangzi?Lake?protection?from?basin-wide?perspective. ??????The?methods?of?spatial?analysis,?landscape?metrics?analysis?and?biostatistical?analysis?are?applied?in?this?paper. Taking?water?landscape?as?the?research?object,?transition?matrix?analysis?is?used?to?describe?transitions?between water?area?and?other?types?of?land?use?during?study?phase.?Aggregation?feature?and?outlier?distribution?of?water?area are?studied?through?spatial?autocorrelation?analysis.?Landscape?metrics?analysis?is?used?to?express?the?features?of area, ?shape, ?aggregation ?and ?connectivity ?quantitively, ?while ?redundancy ?analysis ?is ?employed ?to ?seek ?for ?the driving?forces?of?dynamics?changes. ??????From ?2000 ?to ?2020, ?farmland ?area ?remained ?unchanged ?basically, ?while ?water ?area ?showed ?21%?decrease because?of?water?coverage?being?reclaimed?for?use?as?farmlands.?Urban?area?increased?by?more?than?4?times?by means?of?farmlands?transferred?into.?Water?area?clustered?spatially?with?a?weakening?trend.?The?distribution?of?High value?aggregation?and?Low?value?aggregation?in?water?area?got?more?fragmented,?and?the?area?of?Not?Significant type?increased?by?40%?in?last?decade.?PLAND?and?LPI?of?water?area?had?trend?of?increasing?followed?by?trend?of decreasing.?PD?dropped?gradually?with?an?obvious?decline?of?LSI.?There?were?significant?differences?between?upper and?lower?basin?-?PLAND?and?LPI?of?water?area?in?upper?area?were?about?16%?and?14%?respectively,?while?PLAND and?LPI?in?lower?area?decreased?by?more?than?40%?and?60%?respectively.?Shape?of?water?area?in?lower?area?was more?complicated?than?in?upper?area,?and?LSI?of?upper?and?lower?area?declined?by?32%?and?51%?respectively. Aggregation ?and ?connectivity ?in ?upper ?area ?were ?better ?than ?those ?in ?lower ?area. ?Variation ?partitioning ?of redundancy?analysis?shows?the?54.7%?changes?of?water?landscape?are?a?result?of?natural?and?artificial?factors,?of these ?influences, ?24.2%?of ?the ?changes ?coming ?from ?precipitation ?and ?temperature, ?while ?51.6%?coming ?from contribution?of?human?activities,?the?overlapping?part?is?21.0%. ??????From ?2000 ?to ?2020, ?surface ?area ?of ?water ?in ?Liangzi ?Lake ?has ?decreased ?by ?21%?because ?of ?agricultural reclamation ?directly, ?which ?then ?being ?reclaimed ?for ?urbanized ?purposes, ?leading ?to ?4-time ?area ?increases ?of artificial ?surfaces. ?Farmland ?area ?remains ?unchanged, ?water ?area ?decreased ?attributed ?to ?urbanized ?purposes indirectly.?There?is?a?steady?water?area?aggregation?in?whole?basin,?while?the?relevance?of?water?area?in?local?region are?becoming?decreased?or?disappeared.?Micro-water?body?are?disappearing?with?the?tendency?of?decreasing?of complexity?and?irregularity.?Water?area?distribution?tends?to?be?fragmented,?however?significant?differences?present between?upper?and?lower?basin?areas.?There?are?not?much?changes?of?spatial?distribution?of?water?landscape?in?upper basin?area,?but?in?lower?basin?area,?water?area?reduced?by?nearly?half.?Shoreline?tends?to?be?normalized?and?unified with?an?obvious?obstruction?and?cut?of?water?body.?54.7%?of?the?changes?of?water?landscape?are?the?result?of precipitation,?temperature,?population,?GDP?and?area?ratio?of?farmland?and?artificial?surface.?Human?activities?are the?main?factors,?whose?explanatory?power?are?twice?of?natural?factors.?Population?and?farmland?area?rate?make more?contributions?to?the?water?landscape?area,?meanwhile?GDP?and?urbanization?process?have?more?effects?on shape?complexity?and?connectivity.
Abstract:
Since ?2000, ?large-scale ?comprehensive ?control ?of ?soil ?and ?water ?loss ?has ?been ?carried ?out ?in ?the mountainous ?areas ?of ?Hebei ?Province. ?Through ?measures ?such ?as ?enclosure ?protection, ?afforestation ?and ?grass planting, ?and ?return ?of ?farmland ?to ?forest, ?the ?ecological ?environment ?in ?the ?mountainous ?areas ?has ?been significantly?improved,?especially?the?vegetation?coverage?in?the?mountainous?areas?has?been?significantly?increased. However, ?the ?current ?research ?has ?not ?systematically ?analyzed ?the ?vegetation ?evolution ?law ?and ?causes ?in ?the mountainous?areas?of?Hebei?Province.?It?was?difficult?to?scientifically?evaluate?the?comprehensive?control?of?soil?and water ?loss ?in ?mountainous ?areas ?of ?Hebei ?Province. ?When ?analyzing ?the ?causes ?of ?vegetation ?evolution, ?the traditional ?multiple ?linear ?regression ?method ?usually ?adopts ?the ?climate ?variables ?and ?vegetation ?variables corresponding?to?each?month,?and?fails?to?consider?the?"time-lag?effect"?of?climate?factors,?which?may?lead?to underestimating?the?contribution?of?climate?factors. ??????The?evolution?of?NDVI?in?mountainous?areas?of?Hebei?Province?was?systematically?studied?from?the?aspects?of vegetation?types,?vegetation?phenology?and?time?delay?effect?of?climate?factors.?On?this?basis,?a?multiple?linear regression?model?was?established?considering?the?time?delay?effect?of?climate,?which?is?expected?to?answer?the?cause of?NDVI?evolution?more?accurately.?With?precipitation?P,?temperature?T?and?potential?evapotranspiration?PET?as independent ?variables ?and ?vegetation ?NDVI ?as ?dependent ?variables, ?a ?multiple ?linear ?regression ?model ?was constructed ?to ?improve ?the ?traditional ?residual ?analysis ?method, ?and ?the ?effects ?of ?climate ?change ?and ?human activities?on?vegetation?NDVI?changes?were?stripped?away. ??????The?results?showed?that?NDVI?in?mountainous?areas?of?Hebei?showed?a?continuous?growth?trend?from?2001?to 2022,?with?an?average?growth?rate?of?0.0037/a.?The?growth?rates?of?woodland,?shrub?and?grassland?were?0.003?5/a, 0.004?0/a?and?0.003?8/a,?respectively.?Using?the?Mann-Kendall?trend?test?method?to?analyze?the?significance?of NDVI?change,?it?was?found?that?78%?of?the?regions?showed?a?very?significant?increase?trend,?11%?showed?a significant?increase?trend,?and?only?less?than?2%?showed?a?significant?decrease?or?an?extremely?significant?decrease trend,?indicating?that?the?vegetation?recovery?effect?of?the?whole?Hebei?mountain?region?after?2001?was?remarkable. Due?to?the?influence?of?climate?change,?the?growth?period?of?vegetation?in?mountainous?areas?of?Hebei?Province became?longer,?and?the?start?time?of?the?growing?season?was?advanced?by?9?days?on?average,?while?the?end?time?of the?growing?season?was?advanced?by?only?1?day.?SOS?in?Bashang?Plateau,?Yanshan?District?and?Taihang?Mountain area?advanced?by?6?d,?11?d?and?8?d,?and?EOS?advanced?by?2?d,?1?d?and?1?d,?respectively,?meaning?that?the?whole growing?season?increased?by?4?d,?10?d?and?7?d,?respectively.?The?influence?of?precipitation?on?vegetation?NDVI mainly ?occurs ?in ?the ?same ?month, ?while ?the ?influence ?of ?air ?temperature ?and ?potential ?evapotranspiration ?on vegetation?NDVI?has?a?one-month?lag.?After?considering?the?time-lag?effect?of?climate,?the?contribution?of?climate change?and?human?activities?to?the?evolution?of?NDVI?in?mountainous?areas?of?Hebei?is?39%?and?61%,?respectively. After?considering?the?delay?effect?of?climate?factors,?the?coefficient?of?determination?R2?of?multiple?linear?regression increases?from?0.80?to?0.87,?the?root?mean?square?error?decreases?from?0.086?to?0.071,?and?the?average?absolute?error decreases?from?0.108?to?0.090.?The?performance?of?the?improved?regression?model?is?better?than?that?of?the?original model. ??????Since?2000,?the?main?contribution?of?NDVI?growth?in?mountainous?areas?of?Hebei?Province?has?been?artificial vegetation?restoration,?but?at?the?same?time,?the?lengthening?of?growing?season?caused?by?climate?change?is?also?an important?reason.?Studying?and?identifying?the?impact?of?climate?change?and?human?activities?has?important?guiding significance?for?further?rational?and?efficient?soil?and?water?conservation?in?mountainous?areas.
Since ?2000, ?large-scale ?comprehensive ?control ?of ?soil ?and ?water ?loss ?has ?been ?carried ?out ?in ?the mountainous ?areas ?of ?Hebei ?Province. ?Through ?measures ?such ?as ?enclosure ?protection, ?afforestation ?and ?grass planting, ?and ?return ?of ?farmland ?to ?forest, ?the ?ecological ?environment ?in ?the ?mountainous ?areas ?has ?been significantly?improved,?especially?the?vegetation?coverage?in?the?mountainous?areas?has?been?significantly?increased. However, ?the ?current ?research ?has ?not ?systematically ?analyzed ?the ?vegetation ?evolution ?law ?and ?causes ?in ?the mountainous?areas?of?Hebei?Province.?It?was?difficult?to?scientifically?evaluate?the?comprehensive?control?of?soil?and water ?loss ?in ?mountainous ?areas ?of ?Hebei ?Province. ?When ?analyzing ?the ?causes ?of ?vegetation ?evolution, ?the traditional ?multiple ?linear ?regression ?method ?usually ?adopts ?the ?climate ?variables ?and ?vegetation ?variables corresponding?to?each?month,?and?fails?to?consider?the?"time-lag?effect"?of?climate?factors,?which?may?lead?to underestimating?the?contribution?of?climate?factors. ??????The?evolution?of?NDVI?in?mountainous?areas?of?Hebei?Province?was?systematically?studied?from?the?aspects?of vegetation?types,?vegetation?phenology?and?time?delay?effect?of?climate?factors.?On?this?basis,?a?multiple?linear regression?model?was?established?considering?the?time?delay?effect?of?climate,?which?is?expected?to?answer?the?cause of?NDVI?evolution?more?accurately.?With?precipitation?P,?temperature?T?and?potential?evapotranspiration?PET?as independent ?variables ?and ?vegetation ?NDVI ?as ?dependent ?variables, ?a ?multiple ?linear ?regression ?model ?was constructed ?to ?improve ?the ?traditional ?residual ?analysis ?method, ?and ?the ?effects ?of ?climate ?change ?and ?human activities?on?vegetation?NDVI?changes?were?stripped?away. ??????The?results?showed?that?NDVI?in?mountainous?areas?of?Hebei?showed?a?continuous?growth?trend?from?2001?to 2022,?with?an?average?growth?rate?of?0.0037/a.?The?growth?rates?of?woodland,?shrub?and?grassland?were?0.003?5/a, 0.004?0/a?and?0.003?8/a,?respectively.?Using?the?Mann-Kendall?trend?test?method?to?analyze?the?significance?of NDVI?change,?it?was?found?that?78%?of?the?regions?showed?a?very?significant?increase?trend,?11%?showed?a significant?increase?trend,?and?only?less?than?2%?showed?a?significant?decrease?or?an?extremely?significant?decrease trend,?indicating?that?the?vegetation?recovery?effect?of?the?whole?Hebei?mountain?region?after?2001?was?remarkable. Due?to?the?influence?of?climate?change,?the?growth?period?of?vegetation?in?mountainous?areas?of?Hebei?Province became?longer,?and?the?start?time?of?the?growing?season?was?advanced?by?9?days?on?average,?while?the?end?time?of the?growing?season?was?advanced?by?only?1?day.?SOS?in?Bashang?Plateau,?Yanshan?District?and?Taihang?Mountain area?advanced?by?6?d,?11?d?and?8?d,?and?EOS?advanced?by?2?d,?1?d?and?1?d,?respectively,?meaning?that?the?whole growing?season?increased?by?4?d,?10?d?and?7?d,?respectively.?The?influence?of?precipitation?on?vegetation?NDVI mainly ?occurs ?in ?the ?same ?month, ?while ?the ?influence ?of ?air ?temperature ?and ?potential ?evapotranspiration ?on vegetation?NDVI?has?a?one-month?lag.?After?considering?the?time-lag?effect?of?climate,?the?contribution?of?climate change?and?human?activities?to?the?evolution?of?NDVI?in?mountainous?areas?of?Hebei?is?39%?and?61%,?respectively. After?considering?the?delay?effect?of?climate?factors,?the?coefficient?of?determination?R2?of?multiple?linear?regression increases?from?0.80?to?0.87,?the?root?mean?square?error?decreases?from?0.086?to?0.071,?and?the?average?absolute?error decreases?from?0.108?to?0.090.?The?performance?of?the?improved?regression?model?is?better?than?that?of?the?original model. ??????Since?2000,?the?main?contribution?of?NDVI?growth?in?mountainous?areas?of?Hebei?Province?has?been?artificial vegetation?restoration,?but?at?the?same?time,?the?lengthening?of?growing?season?caused?by?climate?change?is?also?an important?reason.?Studying?and?identifying?the?impact?of?climate?change?and?human?activities?has?important?guiding significance?for?further?rational?and?efficient?soil?and?water?conservation?in?mountainous?areas.
Abstract:
Beidagang?Reservoir?has?the?function?of?water?supply?in?the?utilization?of?water?resources.?The?reservoir can?provide?local?residents?with?drinking?water?and?irrigation?water.?There?is?a?problem?of?salting?in?the?water quality?in?the?Beidagang?Reservoir.?The?salting?law?and?mechanism?of?Beidagang?Reservoir?were?mainly?studied, and ?the ?microbial ?community ?structure ?was ?less ?studied. ?Salinization ?of ?water ?quality ?may ?lead ?to ?significant changes?in?microbial?community?composition?and?diversity.?The?reservoir?mainly?focuses?on?the?exploration?of?the diversity ?of ?microbial ?communities. ?There ?is ?a ?lack ?of ?comparative ?studies ?of ?reservoirs ?between ?different microorganisms ?at ?different ?water ?depths. ?The ?microbial ?communities ?of ?coastal ?reservoirs ?have ?been ?poorly studied.?Microorganisms?are?sensitive?indicators?of?salinity.?The?spatial?distribution?characteristics?of?microbial community?composition?under?salinization?of?water?quality?in?reservoirs?are?still?unclear.?It?is?of?great?significance to?study?the?community?distribution?of?microorganisms?in?salty?reservoirs.?It?can?not?only?understand?the?structural composition?of?microbial?communities?and?the?relationship?between?salinity,?but?also?provide?a?theoretical?basis?for bioremediation?of?high?salt?water?treatment.?It?provides?basic?data?and?scientific?basis?for?Beidagang?Reservoir?to play?the?function?of?water?supply?and?water?resource?utilization.?In ?order ?to ?explore ?the ?salinization ?and ?the ?spatial ?distribution ?characteristics ?of ?microbial ?communities, Beidagang?Reservoir?was?chosen?as?our?research?area.?The?water?samples?from?the?surface,?middle?and?bottom layers ?of ?Beidagang ?Reservoir ?were ?collected ?in ?December ?2021. ?The ?composition ?and ?diversity ?of ?microbial communities?at?different?depths?and?upstream?and?downstream?of?Beidagang?Reservoir?were?analyzed?by?high- throughput?sequencing?technology?to?understand?the?spatial?distribution?characteristics?of?the?microbial?community composition ?structure ?of ?Beidagang ?Reservoir. ?The ?relationship ?between ?dissolved ?total ?solids ?and ?microbial communities?was?explored.?The?influence?of?reservoir?salty?water?on?microbial?community?structure?was?explored. ??????The?results?show?that?there?are?differences?in?the?surface,?middle?and?bottom?layers?of?dissolved?total?solids (TDS)?mass?concentration?in?Beidagang?Reservoir,?and?the?downstream?is?higher?than?that?in?the?upstream.?The main ?dominant ?phylums ?of ?microorganisms ?are?Proteobacteria,?Bacteroidetes?and?Actinobacteria, ?and ?the abundance?of?Proteobacteria?is?more?than?50%.?The?dominant?genera?are?Clade_III?undetermined?genus?(1.10%- 72.72%)?and?Flavobacterium?(0.32%-20.09%),?the?abundance?of?upstream?Clade_III?undetermined?genera?is?higher than?that?of?the?downstream,?and?the?abundance?of?surface?Flavobacterium?is?higher?than?that?of?the?middle?and bottom ?layers. ?There ?were ?significant ?differences ?between ?the ?microbial ?community ?composition ?of ?the ?upper surface ?layer ?and ?the ?middle ?and ?bottom ?microbial ?community ?composition, ?while ?the ?downstream ?microbial community?composition?at?different?depths?was?not?significant,?and?the?composition?of?the?middle?and?bottom microbial?communities?was?similar.?The?Chao1?and?Shannon?indices?showed?that?the?surface?3?000?mg/L),?which?may?inhibit?their?growth. ??????This?study?can?provide?a?theoretical?basis?for?bioremediation?of?salty?water?in?reservoirs.?Therefore,?the?role?of salt-tolerant?microorganisms?on?water?purification?can?be?studied?in?depth.
Beidagang?Reservoir?has?the?function?of?water?supply?in?the?utilization?of?water?resources.?The?reservoir can?provide?local?residents?with?drinking?water?and?irrigation?water.?There?is?a?problem?of?salting?in?the?water quality?in?the?Beidagang?Reservoir.?The?salting?law?and?mechanism?of?Beidagang?Reservoir?were?mainly?studied, and ?the ?microbial ?community ?structure ?was ?less ?studied. ?Salinization ?of ?water ?quality ?may ?lead ?to ?significant changes?in?microbial?community?composition?and?diversity.?The?reservoir?mainly?focuses?on?the?exploration?of?the diversity ?of ?microbial ?communities. ?There ?is ?a ?lack ?of ?comparative ?studies ?of ?reservoirs ?between ?different microorganisms ?at ?different ?water ?depths. ?The ?microbial ?communities ?of ?coastal ?reservoirs ?have ?been ?poorly studied.?Microorganisms?are?sensitive?indicators?of?salinity.?The?spatial?distribution?characteristics?of?microbial community?composition?under?salinization?of?water?quality?in?reservoirs?are?still?unclear.?It?is?of?great?significance to?study?the?community?distribution?of?microorganisms?in?salty?reservoirs.?It?can?not?only?understand?the?structural composition?of?microbial?communities?and?the?relationship?between?salinity,?but?also?provide?a?theoretical?basis?for bioremediation?of?high?salt?water?treatment.?It?provides?basic?data?and?scientific?basis?for?Beidagang?Reservoir?to play?the?function?of?water?supply?and?water?resource?utilization.?In ?order ?to ?explore ?the ?salinization ?and ?the ?spatial ?distribution ?characteristics ?of ?microbial ?communities, Beidagang?Reservoir?was?chosen?as?our?research?area.?The?water?samples?from?the?surface,?middle?and?bottom layers ?of ?Beidagang ?Reservoir ?were ?collected ?in ?December ?2021. ?The ?composition ?and ?diversity ?of ?microbial communities?at?different?depths?and?upstream?and?downstream?of?Beidagang?Reservoir?were?analyzed?by?high- throughput?sequencing?technology?to?understand?the?spatial?distribution?characteristics?of?the?microbial?community composition ?structure ?of ?Beidagang ?Reservoir. ?The ?relationship ?between ?dissolved ?total ?solids ?and ?microbial communities?was?explored.?The?influence?of?reservoir?salty?water?on?microbial?community?structure?was?explored. ??????The?results?show?that?there?are?differences?in?the?surface,?middle?and?bottom?layers?of?dissolved?total?solids (TDS)?mass?concentration?in?Beidagang?Reservoir,?and?the?downstream?is?higher?than?that?in?the?upstream.?The main ?dominant ?phylums ?of ?microorganisms ?are?Proteobacteria,?Bacteroidetes?and?Actinobacteria, ?and ?the abundance?of?Proteobacteria?is?more?than?50%.?The?dominant?genera?are?Clade_III?undetermined?genus?(1.10%- 72.72%)?and?Flavobacterium?(0.32%-20.09%),?the?abundance?of?upstream?Clade_III?undetermined?genera?is?higher than?that?of?the?downstream,?and?the?abundance?of?surface?Flavobacterium?is?higher?than?that?of?the?middle?and bottom ?layers. ?There ?were ?significant ?differences ?between ?the ?microbial ?community ?composition ?of ?the ?upper surface ?layer ?and ?the ?middle ?and ?bottom ?microbial ?community ?composition, ?while ?the ?downstream ?microbial community?composition?at?different?depths?was?not?significant,?and?the?composition?of?the?middle?and?bottom microbial?communities?was?similar.?The?Chao1?and?Shannon?indices?showed?that?the?surface?3?000?mg/L),?which?may?inhibit?their?growth. ??????This?study?can?provide?a?theoretical?basis?for?bioremediation?of?salty?water?in?reservoirs.?Therefore,?the?role?of salt-tolerant?microorganisms?on?water?purification?can?be?studied?in?depth.
Abstract:
The?change?of?regional?land?use?affects?carbon?emission?and?carbon?sequestration?processes,?which?in turn?causes?changes?in?the?carbon?cycle?and?carbon?storage?in?terrestrial?ecosystems.?Based?on?the?China?land?cover dataset,?the?carbon?storage?and?sequestration?module?of?the?integrated?valuation?of?ecosystem?services?and?trade-offs model?was?used?to?estimate?the?carbon?storage?and?changes?in?terrestrial?ecosystems?from?1990?to?2020?in?the?Haihe River?basin.?The?patch-generating?land?use?simulation?model?was?combined?to?predict?future?land?use?and?carbon storage.?The?integrated?valuation?of?ecosystem?services?and?trade-offs?model?could?quantify?regional?carbon?storage based?on?regional?carbon?density.?The?carbon?storage?and?sequestration?module?mainly?depended?on?land?cover types ?and ?a ?basic ?carbon ?pool ?model. ?The ?basic ?carbon ?pool ?model ?divided ?carbon ?storage ?into ?four ?types: aboveground?biomass?carbon,?belowground?biomass?carbon,?soil?carbon,?and?dead?organic?matter?carbon.?The?patch- generating?land?use?simulation?model?is?a?cellular?automata?model?based?on?raster?data?that?could?simulate?land?use changes?at?the?patch?scale.?It?integrated?the?land?expansion?analysis?strategy?and?a?cellular?automata?model?based?on multiple?random?patch?seeds,?which?could?be?used?to?explore?the?driving?factors?of?land?expansion?and?predict?the patch-level?evolution?of?land?use?landscapes.?Additionally,?geodetector?was?utilized?to?quantitatively?explain?the driving?mechanisms?of?carbon?storage?in?the?Haihe?River?basin.?Geodetector?is?a?method?for?detecting?spatial variations ?of ?geographic ?features ?and ?revealing ?their ?driving ?factors. ?This ?method ?allows ?for ?direct ?correlation analysis ?between ?the ?dependent ?variable ?and ?the ?independent ?variables ?without ?considering ?collinearity ?among factors. ??????The?results?showed?that:?(1)?the?carbon?storage?decreased?by?a?total?of?4.98%?from?1990?to?2020,?with?the?year 2003?as?the?turning?point.?Carbon?storage?exhibited?a?fluctuating?declining?trend,?followed?by?a?decrease?in?the magnitude?of?fluctuations,?fluctuating?around?2.05?billion?tons.?(2)?The?spatial?distribution?of?carbon?density?in?the basin?exhibited?significant?heterogeneity.?High?carbon?density?values?were?mainly?concentrated?in?the?eastern?and northern?forested?areas?of?the?basin,?while?low?values?were?primarily?distributed?in?cities?and?the?Bohai?Bay?region. (3)?In?2030,?apart?from?the?scenario?of?rapid?urban?development,?other?scenarios?show?varying?degrees?of?carbon stock?increase.?The?scenario?with?the?highest?increase?is?the?ecological?conservation?scenario,?which?has?a?carbon stock ?of ?0.77 ?million ?tons ?higher ?than ?the?scenario ?of ?rapid ?urban ?development. ?This ?indicates ?that?ecological improvement?is?beneficial?for?carbon?sequestration?in?regional?terrestrial?ecosystems.?In?the?scenario?of?rapid?urban development,?the?expansion?of?impervious?surfaces?encroached?upon?cropland,?leading?to?a?significant?reduction?in carbon?storage?in?the?eastern?plain?area?of?the?Haihe?River?basin.?(4)?Natural?factors?had?a?higher?explanatory?power than?socio-economic?factors,?and?the?interaction?between?population?density,?DEM,?and?other?climatic?factors?has the?strongest?explanatory?power?for?changes?in?carbon?stock.?The?results?will?provide?certain?theoretical?support?for land?regulation?and?future?low-carbon?development?in?the?Haihe?River?basin?and?also?serve?as?a?reference?for?better implementation?of?the?carbon?peaking?and?carbon?neutrality?goals.
The?change?of?regional?land?use?affects?carbon?emission?and?carbon?sequestration?processes,?which?in turn?causes?changes?in?the?carbon?cycle?and?carbon?storage?in?terrestrial?ecosystems.?Based?on?the?China?land?cover dataset,?the?carbon?storage?and?sequestration?module?of?the?integrated?valuation?of?ecosystem?services?and?trade-offs model?was?used?to?estimate?the?carbon?storage?and?changes?in?terrestrial?ecosystems?from?1990?to?2020?in?the?Haihe River?basin.?The?patch-generating?land?use?simulation?model?was?combined?to?predict?future?land?use?and?carbon storage.?The?integrated?valuation?of?ecosystem?services?and?trade-offs?model?could?quantify?regional?carbon?storage based?on?regional?carbon?density.?The?carbon?storage?and?sequestration?module?mainly?depended?on?land?cover types ?and ?a ?basic ?carbon ?pool ?model. ?The ?basic ?carbon ?pool ?model ?divided ?carbon ?storage ?into ?four ?types: aboveground?biomass?carbon,?belowground?biomass?carbon,?soil?carbon,?and?dead?organic?matter?carbon.?The?patch- generating?land?use?simulation?model?is?a?cellular?automata?model?based?on?raster?data?that?could?simulate?land?use changes?at?the?patch?scale.?It?integrated?the?land?expansion?analysis?strategy?and?a?cellular?automata?model?based?on multiple?random?patch?seeds,?which?could?be?used?to?explore?the?driving?factors?of?land?expansion?and?predict?the patch-level?evolution?of?land?use?landscapes.?Additionally,?geodetector?was?utilized?to?quantitatively?explain?the driving?mechanisms?of?carbon?storage?in?the?Haihe?River?basin.?Geodetector?is?a?method?for?detecting?spatial variations ?of ?geographic ?features ?and ?revealing ?their ?driving ?factors. ?This ?method ?allows ?for ?direct ?correlation analysis ?between ?the ?dependent ?variable ?and ?the ?independent ?variables ?without ?considering ?collinearity ?among factors. ??????The?results?showed?that:?(1)?the?carbon?storage?decreased?by?a?total?of?4.98%?from?1990?to?2020,?with?the?year 2003?as?the?turning?point.?Carbon?storage?exhibited?a?fluctuating?declining?trend,?followed?by?a?decrease?in?the magnitude?of?fluctuations,?fluctuating?around?2.05?billion?tons.?(2)?The?spatial?distribution?of?carbon?density?in?the basin?exhibited?significant?heterogeneity.?High?carbon?density?values?were?mainly?concentrated?in?the?eastern?and northern?forested?areas?of?the?basin,?while?low?values?were?primarily?distributed?in?cities?and?the?Bohai?Bay?region. (3)?In?2030,?apart?from?the?scenario?of?rapid?urban?development,?other?scenarios?show?varying?degrees?of?carbon stock?increase.?The?scenario?with?the?highest?increase?is?the?ecological?conservation?scenario,?which?has?a?carbon stock ?of ?0.77 ?million ?tons ?higher ?than ?the?scenario ?of ?rapid ?urban ?development. ?This ?indicates ?that?ecological improvement?is?beneficial?for?carbon?sequestration?in?regional?terrestrial?ecosystems.?In?the?scenario?of?rapid?urban development,?the?expansion?of?impervious?surfaces?encroached?upon?cropland,?leading?to?a?significant?reduction?in carbon?storage?in?the?eastern?plain?area?of?the?Haihe?River?basin.?(4)?Natural?factors?had?a?higher?explanatory?power than?socio-economic?factors,?and?the?interaction?between?population?density,?DEM,?and?other?climatic?factors?has the?strongest?explanatory?power?for?changes?in?carbon?stock.?The?results?will?provide?certain?theoretical?support?for land?regulation?and?future?low-carbon?development?in?the?Haihe?River?basin?and?also?serve?as?a?reference?for?better implementation?of?the?carbon?peaking?and?carbon?neutrality?goals.
Abstract:
The?inter-basin?water?diversion?projects?transfer?the?water?resources?from?basins?with?abundant?water?to that?with?scarce?water,?which?aims?to?address?the?problem?of?uneven?spatial?and?temporal?distribution?of?water resources.?The?Yangtze-to-Huaihe?River?Water?Diversion?Project?is?a?major?strategic?water?resource?allocation project?across?Yangtze?River?and?Huaihe?River?basins.?The?middle?and?lower?reaches?of?the?Yangtze?River?and?the Huaihe?River?basin?are?located?in?the?eastern?monsoon?region?of?China.?The?drought?disasters?occur?frequently?in these?regions?with?the?influence?of?monsoon?climate.?Due?to?the?temporal?fluctuation?and?spatial?variability?of regional?water?supply,?the?water?source?and?the?water?destination?regions?of?the?project?are?prone?to?the?risk?of concurrent ?droughts. ?The ?simultaneous ?occurrence ?of ?drought ?events ?across ?the ?water ?source ?and ?the ?water destination?regions?or?other?conditions?that?are?not?conducive?to?water?transfer?would?have?a?significant?impact?on the?normal?scheduling?operation?and?efficiency?of?the?project.?In?addition,?with?the?effects?of?climate?change?and human?activities,?the?global?water?cycle?will?be?further?intensified.?Compound?extreme?events?such?as?drought,?high temperature?and?heat?waves?on?a?global?scale?will?be?increasing,?which?have?a?serious?impact?on?regional?water resources ?management, ?ecosystem ?and ?sustainable ?socio-economic ?development. ?Therefore, ?it ?is ?of ?great significance?to?explore?the?risk?of?concurrent?drought?in?the?water?source?and?the?water?destination?regions?of?the Yangtze-to-Huaihe ?River ?Water ?Diversion ?Project ?under ?climate ?change ?to ?provide ?scientific ?support ?for ?the operation?of?project?scheduling?and?sustainable?utilization?of?water?resources. ??????The?risk?of?concurrent?drought?probability?between?the?water?source?and?destination?regions?of?Yangtze-to- Huaihe?River?Water?Diversion?Project?was?investigated.?The?meteorological?observation?and?the?Coupled?Model Intercomparison?Project?Phase?6?(CMIP6)?climate?model?dataset?of?precipitation?were?integrated?for?both?historical and?future?assessment.?Precipitation?from?nine?CMIP6?dataset?with?three?scenarios?was?first?bias-corrected?using?a quantile?mapping?approach.?The?Standardized?Precipitation?Evapotranspiration?Index?(SPEI)?with?a?time?scale?of?6 and ?12 ?months ?was ?calculated ?by ?monthly ?precipitation ?and ?temperature ?to ?describe ?drought ?condition. ?The appropriate?marginal?distribution?was?selected?to?fit?the?SPEI?sequence.?The?Copula?theory?was?then?applied?to construct?the?joint?distribution?of?drought?index?in?the?water?source?and?destination?regions.?The?drought?evolution patterns?and?drought?encounter?risks?from?1960?to?2020?were?evaluated.?And?further?analysis?of?the?future?changes in?drought?encounter?risks?under?different?scenarios?based?on?CMIP6?data?was?carried?out. ??????The?results?showed?that?the?frequency?of?drought?occurrence?in?the?water?source?and?destination?regions?from 1960?to?2020?was?27.32%?and?29.78%?respectively.?In?the?future?scenarios,?there?would?be?a?significant?increase?in the?frequency?of?drought?occurrence?in?both?regions,?especially?in?the?high?emission?scenario?where?the?frequency?of severe?drought?occurrence?increases?by?more?than?10%.?The?probability?of?simultaneous?drought?occurrence?in?the non-flood?season?of?the?water?source?and?destination?regions?was?5.49%?higher?compared?to?the?flood?season.?The frequency?of?drought?encounters?during?the?flood?season?and?throughout?the?year?was?expected?to?significantly increase,?while?the?frequency?of?non-flood?season?drought?encounters?was?slightly?reduced.?In?the?medium?to?high emission?scenarios?(SSP2-4.5?and?SSP5-8.5),?the?frequency?of?long-term?drought?encounters?was?relatively?higher. ??????The?SPEI?could?well?capture?the?regional?drought?conditions?in?both?the?water?source?and?destination?regions. The?joint?distribution?of?SPEI?by?the?Clayton?Copula?function?was?capable?to?characterize?the?concurrent?drought between?the?water?source?and?destination?regions.?The?probability?of?concurrent?drought?in?the?two?regions?during the?non-flood?season?was?relatively?higher?than?that?in?the?flood?season.?In?the?future?scenarios,?there?would?be?a significant?increase?in?the?frequency?of?drought?occurrence?in?both?regions.?And?the?frequency?of?drought?encounters was?also?projected?to?increase?in?the?future.?Therefore,?it?is?urgent?to?formulate?adaptive?strategies?to?ensure?the normal?operation?management?of?water?transfer?projects?and?the?sustainable?utilization?of?water?resources.
The?inter-basin?water?diversion?projects?transfer?the?water?resources?from?basins?with?abundant?water?to that?with?scarce?water,?which?aims?to?address?the?problem?of?uneven?spatial?and?temporal?distribution?of?water resources.?The?Yangtze-to-Huaihe?River?Water?Diversion?Project?is?a?major?strategic?water?resource?allocation project?across?Yangtze?River?and?Huaihe?River?basins.?The?middle?and?lower?reaches?of?the?Yangtze?River?and?the Huaihe?River?basin?are?located?in?the?eastern?monsoon?region?of?China.?The?drought?disasters?occur?frequently?in these?regions?with?the?influence?of?monsoon?climate.?Due?to?the?temporal?fluctuation?and?spatial?variability?of regional?water?supply,?the?water?source?and?the?water?destination?regions?of?the?project?are?prone?to?the?risk?of concurrent ?droughts. ?The ?simultaneous ?occurrence ?of ?drought ?events ?across ?the ?water ?source ?and ?the ?water destination?regions?or?other?conditions?that?are?not?conducive?to?water?transfer?would?have?a?significant?impact?on the?normal?scheduling?operation?and?efficiency?of?the?project.?In?addition,?with?the?effects?of?climate?change?and human?activities,?the?global?water?cycle?will?be?further?intensified.?Compound?extreme?events?such?as?drought,?high temperature?and?heat?waves?on?a?global?scale?will?be?increasing,?which?have?a?serious?impact?on?regional?water resources ?management, ?ecosystem ?and ?sustainable ?socio-economic ?development. ?Therefore, ?it ?is ?of ?great significance?to?explore?the?risk?of?concurrent?drought?in?the?water?source?and?the?water?destination?regions?of?the Yangtze-to-Huaihe ?River ?Water ?Diversion ?Project ?under ?climate ?change ?to ?provide ?scientific ?support ?for ?the operation?of?project?scheduling?and?sustainable?utilization?of?water?resources. ??????The?risk?of?concurrent?drought?probability?between?the?water?source?and?destination?regions?of?Yangtze-to- Huaihe?River?Water?Diversion?Project?was?investigated.?The?meteorological?observation?and?the?Coupled?Model Intercomparison?Project?Phase?6?(CMIP6)?climate?model?dataset?of?precipitation?were?integrated?for?both?historical and?future?assessment.?Precipitation?from?nine?CMIP6?dataset?with?three?scenarios?was?first?bias-corrected?using?a quantile?mapping?approach.?The?Standardized?Precipitation?Evapotranspiration?Index?(SPEI)?with?a?time?scale?of?6 and ?12 ?months ?was ?calculated ?by ?monthly ?precipitation ?and ?temperature ?to ?describe ?drought ?condition. ?The appropriate?marginal?distribution?was?selected?to?fit?the?SPEI?sequence.?The?Copula?theory?was?then?applied?to construct?the?joint?distribution?of?drought?index?in?the?water?source?and?destination?regions.?The?drought?evolution patterns?and?drought?encounter?risks?from?1960?to?2020?were?evaluated.?And?further?analysis?of?the?future?changes in?drought?encounter?risks?under?different?scenarios?based?on?CMIP6?data?was?carried?out. ??????The?results?showed?that?the?frequency?of?drought?occurrence?in?the?water?source?and?destination?regions?from 1960?to?2020?was?27.32%?and?29.78%?respectively.?In?the?future?scenarios,?there?would?be?a?significant?increase?in the?frequency?of?drought?occurrence?in?both?regions,?especially?in?the?high?emission?scenario?where?the?frequency?of severe?drought?occurrence?increases?by?more?than?10%.?The?probability?of?simultaneous?drought?occurrence?in?the non-flood?season?of?the?water?source?and?destination?regions?was?5.49%?higher?compared?to?the?flood?season.?The frequency?of?drought?encounters?during?the?flood?season?and?throughout?the?year?was?expected?to?significantly increase,?while?the?frequency?of?non-flood?season?drought?encounters?was?slightly?reduced.?In?the?medium?to?high emission?scenarios?(SSP2-4.5?and?SSP5-8.5),?the?frequency?of?long-term?drought?encounters?was?relatively?higher. ??????The?SPEI?could?well?capture?the?regional?drought?conditions?in?both?the?water?source?and?destination?regions. The?joint?distribution?of?SPEI?by?the?Clayton?Copula?function?was?capable?to?characterize?the?concurrent?drought between?the?water?source?and?destination?regions.?The?probability?of?concurrent?drought?in?the?two?regions?during the?non-flood?season?was?relatively?higher?than?that?in?the?flood?season.?In?the?future?scenarios,?there?would?be?a significant?increase?in?the?frequency?of?drought?occurrence?in?both?regions.?And?the?frequency?of?drought?encounters was?also?projected?to?increase?in?the?future.?Therefore,?it?is?urgent?to?formulate?adaptive?strategies?to?ensure?the normal?operation?management?of?water?transfer?projects?and?the?sustainable?utilization?of?water?resources.
Abstract:
Total?length?of?the?Yangtze-to-Huaihe?Water?Transfer?Project?is?723?km,?more?than?100?km?of?the?river section?is?distributed?with?weak?and?medium?expansive?soil,?and?the?maximum?excavation?depth?of?the?canal?is?46 m.?The?stability?of?the?expansive?soil?section?is?one?of?the?key?technical?problems?of?the?project.?In?the?preliminary design?stage,?the?treatment?measures?of?over?digging,?replacing?and?filling?cement-modified?soil?were?proposed?for the?expanded?land?section,?but?some?ecological?and?environmental?problems?were?generated,?such?as?the?cement modified?soil?is?easy?to?be?alkali,?and?makes?it?difficult?for?plants?to?grow.?Moreover,?slope?overcutting?would produce?a?large?amount?of?waste?soil?which?is?adverse?to?the?ecological?environment.?Whether?simplified?treatment measures?can?be?applied?to?some?weak?expansion?channels?with?slope?heights?less?than?10?m?is?a?question?that?needs to?be?addressed.?Under?the?principle?of?ecological?priority?and?technological?innovation,?the?researchers?carried?out systematic ?research ?work ?using ?field ?experiments, ?indoor ?unit ?tests, ?and ?numerical ?analysis. ?The ?ecological restoration ?scheme ?using ?surface ?cultivated ?soil ?and ?grass ?was ?put ?forward ?through ?field ?sampling ?tests ?and numerical?analysis?for?the?low?river?embankment?in?the?weak?expansive?soil?around?Chaohu?Lake.?An?ecological substrate?was?developed?to?solve?the?problems?such?as?soil?alkali?plate?and?plant?growth?difficulty?in?the?medium expansive?cement-modified?soil?replacement?layer.?The?field?pilot?test?proved?that?the?ecological?substrate?is?a?new kind?of?ecological?slope?planting?material.?An?ecologically?friendly?expansive?soil?slope?protection?structure?is proposed?using?unsaturated?soil?theory?based?on?the?characteristics?of?a?large?difference?in?permeability?coefficient between?sand?and?clay.?This?structure?can?better?solve?the?dual?protection?requirements?of?expansive?soil?slopes?to prevent?rainfall?infiltration?and?water?evaporation.?At?the?same?time,?it?can?also?use?the?compression?effect?of?the sand?layer?to?restrain?the?expansion?and?deformation?of?soil?layer. ??????The?field?pilot?test?and?application?results?show?that?the?ecological?substrate?developed?can?adapt?to?the?planting needs ?of ?cement-modified ?soil ?so ?that ?the ?slope ?can ?achieve ?a ?good ?greening ?effect. ?The ?double-layer ?slope protection?structure?can?better?solve?the?dual?protection?requirements?of?the?expansive?soil?slope?to?prevent?rainfall infiltration?and?water?evaporation.?The?expansion?and?deformation?of?the?soil?layer?can?also?be?controlled?by?the compression?effect?of?the?sand?layer. ??????The?research?results?provide?technical?support?for?the?engineering?design?and?late?operation?management?of?the project,?effectively?solving?the?technical?problems?related?to?the?expansion?land?section?of?the?project,?and?provide?a basis ?for ?the ?design ?and ?optimization ?of ?related ?river ?slope. ?Together, ?breakthroughs ?have ?been ?made ?in ?the engineering?application?of?unsaturated?soil?theory?and?the?ecological?treatment?of?expansive?soil?slopes.
Total?length?of?the?Yangtze-to-Huaihe?Water?Transfer?Project?is?723?km,?more?than?100?km?of?the?river section?is?distributed?with?weak?and?medium?expansive?soil,?and?the?maximum?excavation?depth?of?the?canal?is?46 m.?The?stability?of?the?expansive?soil?section?is?one?of?the?key?technical?problems?of?the?project.?In?the?preliminary design?stage,?the?treatment?measures?of?over?digging,?replacing?and?filling?cement-modified?soil?were?proposed?for the?expanded?land?section,?but?some?ecological?and?environmental?problems?were?generated,?such?as?the?cement modified?soil?is?easy?to?be?alkali,?and?makes?it?difficult?for?plants?to?grow.?Moreover,?slope?overcutting?would produce?a?large?amount?of?waste?soil?which?is?adverse?to?the?ecological?environment.?Whether?simplified?treatment measures?can?be?applied?to?some?weak?expansion?channels?with?slope?heights?less?than?10?m?is?a?question?that?needs to?be?addressed.?Under?the?principle?of?ecological?priority?and?technological?innovation,?the?researchers?carried?out systematic ?research ?work ?using ?field ?experiments, ?indoor ?unit ?tests, ?and ?numerical ?analysis. ?The ?ecological restoration ?scheme ?using ?surface ?cultivated ?soil ?and ?grass ?was ?put ?forward ?through ?field ?sampling ?tests ?and numerical?analysis?for?the?low?river?embankment?in?the?weak?expansive?soil?around?Chaohu?Lake.?An?ecological substrate?was?developed?to?solve?the?problems?such?as?soil?alkali?plate?and?plant?growth?difficulty?in?the?medium expansive?cement-modified?soil?replacement?layer.?The?field?pilot?test?proved?that?the?ecological?substrate?is?a?new kind?of?ecological?slope?planting?material.?An?ecologically?friendly?expansive?soil?slope?protection?structure?is proposed?using?unsaturated?soil?theory?based?on?the?characteristics?of?a?large?difference?in?permeability?coefficient between?sand?and?clay.?This?structure?can?better?solve?the?dual?protection?requirements?of?expansive?soil?slopes?to prevent?rainfall?infiltration?and?water?evaporation.?At?the?same?time,?it?can?also?use?the?compression?effect?of?the sand?layer?to?restrain?the?expansion?and?deformation?of?soil?layer. ??????The?field?pilot?test?and?application?results?show?that?the?ecological?substrate?developed?can?adapt?to?the?planting needs ?of ?cement-modified ?soil ?so ?that ?the ?slope ?can ?achieve ?a ?good ?greening ?effect. ?The ?double-layer ?slope protection?structure?can?better?solve?the?dual?protection?requirements?of?the?expansive?soil?slope?to?prevent?rainfall infiltration?and?water?evaporation.?The?expansion?and?deformation?of?the?soil?layer?can?also?be?controlled?by?the compression?effect?of?the?sand?layer. ??????The?research?results?provide?technical?support?for?the?engineering?design?and?late?operation?management?of?the project,?effectively?solving?the?technical?problems?related?to?the?expansion?land?section?of?the?project,?and?provide?a basis ?for ?the ?design ?and ?optimization ?of ?related ?river ?slope. ?Together, ?breakthroughs ?have ?been ?made ?in ?the engineering?application?of?unsaturated?soil?theory?and?the?ecological?treatment?of?expansive?soil?slopes.
Abstract:
The?main?canal?of?the?Middle?Route?of?the?South-to-North?Water?Transfers?Project?is?separated?by?gates into?series?channel?pools.?In?case?of?emergencies?and?other?situations,?the?synchronous?operation?technology?of?gates is?often?adopted?to?rapidly?reduce?the?water?flow?in?a?large?range.?Rapid?closing?of?the?gates?at?both?ends?of?the?canal pool?will?cause?continuous?oscillation?of?the?water?level?and?flow?in?the?canal?pool,?and?affect?the?efficiency?and effect?of?the?gate?feedback?control.?If?the?gate?is?not?properly?controlled,?the?water?is?easy?to?overflow.?It?is?of?great significance?to?deeply?understand?the?hydraulic?response?characteristics?of?synchronous?closing?of?gate?and?the influence?law?of?related?factors?for?guiding?the?control?of?gate?scientifically?and?ensuring?the?operation?safety?of?the project. ??????Based?on?Saint-Venant?equation?group,?a?one-dimensional?unsteady?gradually?varied?flow?model?for?the?main canal?of?the?Middle?Route?of?the?South-to-North?Water?Transfers?Project?was?constructed.?Taking?the?canal?pool between ?Diaohe ?aqueduct ?gate ?and ?Tuanhe ?aqueduct ?gate ?as ?the ?research ?object, ?the ?hydraulic ?response ?of synchronous?closing?of?the?gate?was?simulated,?and?the?hydraulic?response?characteristics?such?as?peak?water?level, time?spent?to?reach?the?peak?water?level,?frequency?and?amplitude?of?hydraulic?oscillation?before?the?gate?were analyzed.?By?changing?the?control?mode?of?gate?and?the?operating?conditions?of?canal,?the?influences?of?gate?closing duration, ?gate ?closing ?amplitude, ?operating ?water ?level, ?water ?delivery ?flow ?and ?canal ?roughness ?on ?hydraulic response?characteristics?were?analyzed?and?summarized. ??????Simulation?results?showed?that?the?rise?process?of?hydraulic?oscillation?was?fast,?but?the?fall?process?was?slow. The?amplitude?of?the?wave?was?approximately?logarithmic?function?attenuation?with?time,?and?the?time?interval?of the?adjacent?wave?peaks?and?valleys?gradually?tended?to?be?consistent.?The?peak?height?of?backwater?and?amplitude of?hydraulic?oscillation?in?front?of?the?gate?can?be?reduced?approximately?linearly?by?slowly?closing?and?decreasing closing?amplitude.?The?decreasing?amplitude?was?a?zonal?distribution?function?with?gate?closing?time.?With?the increase?of?operating?water?level,?the?peak?value?of?rising?water?in?front?of?the?gate?decreased?linearly.?The?time taken ?to ?reach ?the ?peak ?and ?the ?amplitude ?of ?hydraulic ?oscillation ?had ?no ?obvious ?change, ?but ?the ?oscillation frequency?increased?slightly.?With?the?increase?of?the?water?flow,?the?peak?value?of?backwater?in?front?of?the?gate increased?linearly.?The?time?taken?to?reach?the?peak?had?no?obvious?change?in?the?frequency?of?hydraulic?oscillation, but?the?amplitude?decreased?obviously?and?the?attenuation?became?faster.?With?the?increase?of?roughness,?the?peak of?backwater?before?the?gate?increased?linearly,?the?time?taken?to?reach?the?peak,?and?the?frequency?and?amplitude?of hydraulic?oscillation?had?no?obvious?change. ??????The?hydraulic?response?is?determined?by?the?difference?of?the?movement?characteristics?between?the?increasing wave?and?the?decreasing?wave,?as?well?as?the?difference?while?traveling?downstream?and?upstream,?and?the?energy dissipation?along?the?travel.?The?amplitude?of?hydraulic?oscillation?is?sensitive?to?the?closing?speed?and?closing amplitude?of?the?gate.?The?value?deviation?of?roughness?can?be?ignored?when?estimating?peak?backwater?before?the gate.
The?main?canal?of?the?Middle?Route?of?the?South-to-North?Water?Transfers?Project?is?separated?by?gates into?series?channel?pools.?In?case?of?emergencies?and?other?situations,?the?synchronous?operation?technology?of?gates is?often?adopted?to?rapidly?reduce?the?water?flow?in?a?large?range.?Rapid?closing?of?the?gates?at?both?ends?of?the?canal pool?will?cause?continuous?oscillation?of?the?water?level?and?flow?in?the?canal?pool,?and?affect?the?efficiency?and effect?of?the?gate?feedback?control.?If?the?gate?is?not?properly?controlled,?the?water?is?easy?to?overflow.?It?is?of?great significance?to?deeply?understand?the?hydraulic?response?characteristics?of?synchronous?closing?of?gate?and?the influence?law?of?related?factors?for?guiding?the?control?of?gate?scientifically?and?ensuring?the?operation?safety?of?the project. ??????Based?on?Saint-Venant?equation?group,?a?one-dimensional?unsteady?gradually?varied?flow?model?for?the?main canal?of?the?Middle?Route?of?the?South-to-North?Water?Transfers?Project?was?constructed.?Taking?the?canal?pool between ?Diaohe ?aqueduct ?gate ?and ?Tuanhe ?aqueduct ?gate ?as ?the ?research ?object, ?the ?hydraulic ?response ?of synchronous?closing?of?the?gate?was?simulated,?and?the?hydraulic?response?characteristics?such?as?peak?water?level, time?spent?to?reach?the?peak?water?level,?frequency?and?amplitude?of?hydraulic?oscillation?before?the?gate?were analyzed.?By?changing?the?control?mode?of?gate?and?the?operating?conditions?of?canal,?the?influences?of?gate?closing duration, ?gate ?closing ?amplitude, ?operating ?water ?level, ?water ?delivery ?flow ?and ?canal ?roughness ?on ?hydraulic response?characteristics?were?analyzed?and?summarized. ??????Simulation?results?showed?that?the?rise?process?of?hydraulic?oscillation?was?fast,?but?the?fall?process?was?slow. The?amplitude?of?the?wave?was?approximately?logarithmic?function?attenuation?with?time,?and?the?time?interval?of the?adjacent?wave?peaks?and?valleys?gradually?tended?to?be?consistent.?The?peak?height?of?backwater?and?amplitude of?hydraulic?oscillation?in?front?of?the?gate?can?be?reduced?approximately?linearly?by?slowly?closing?and?decreasing closing?amplitude.?The?decreasing?amplitude?was?a?zonal?distribution?function?with?gate?closing?time.?With?the increase?of?operating?water?level,?the?peak?value?of?rising?water?in?front?of?the?gate?decreased?linearly.?The?time taken ?to ?reach ?the ?peak ?and ?the ?amplitude ?of ?hydraulic ?oscillation ?had ?no ?obvious ?change, ?but ?the ?oscillation frequency?increased?slightly.?With?the?increase?of?the?water?flow,?the?peak?value?of?backwater?in?front?of?the?gate increased?linearly.?The?time?taken?to?reach?the?peak?had?no?obvious?change?in?the?frequency?of?hydraulic?oscillation, but?the?amplitude?decreased?obviously?and?the?attenuation?became?faster.?With?the?increase?of?roughness,?the?peak of?backwater?before?the?gate?increased?linearly,?the?time?taken?to?reach?the?peak,?and?the?frequency?and?amplitude?of hydraulic?oscillation?had?no?obvious?change. ??????The?hydraulic?response?is?determined?by?the?difference?of?the?movement?characteristics?between?the?increasing wave?and?the?decreasing?wave,?as?well?as?the?difference?while?traveling?downstream?and?upstream,?and?the?energy dissipation?along?the?travel.?The?amplitude?of?hydraulic?oscillation?is?sensitive?to?the?closing?speed?and?closing amplitude?of?the?gate.?The?value?deviation?of?roughness?can?be?ignored?when?estimating?peak?backwater?before?the gate.
Abstract:
Water?keeping?weir?is?a?new?type?of?overflow?weir,?characterized?by?small?pressure?in?two?sections?of?the transmission?line,?and?simple?hydraulic?control.?In?order?to?enhance?the?water?conveyance?capacity?of?water?keeping weir?in?large?water?diversion?projects.?First?of?all,?based?on?the?actual?operation?of?the?project,?the?RNG?k-ε?turbulent flow?model?is?used?to?close?the?control?equations?and?establish?a?three-dimensional?isometric?numerical?simulation model?of?the?water?keeping?weir,?and?the?simulated?head?and?flow?velocity?of?the?pressure?measuring?tube?are?in good?agreement?with?the?measured?data,?and?on?the?premise?of?ensuring?the?accuracy?of?the?flow?pattern?in?the simulated?water?keeping?weir,?the?influence?of?the?water?keeping?weir?body?parameters?on?the?over-flow?capacity?of the?box?culvert?-?water?keeping?weir?water?conveyance?system?is?investigated.?It?revealed?the?mechanism?of?the generation?and?development?of?annular?vortex?zones?in?the?weir?section,?and?determined?that?the?dispersion?of?high velocity?water?flow?zone?caused?by?the?height?of?the?water?keeping?weir?and?the?presence?of?annular?vortex?zones are?the?main?bottlenecks?affecting?the?improvement?of?flow?capacity.?Thus,?the?proposed?solution?of?reducing?the height?of?the?water?keeping?weir?concentrate?the?high?velocity?water?flow?zone?and?reduce?the?scope?of?the?annular vortex?zone?to?reduce?the?energy?dissipation?in?the?weir?section,?so?as?to?achieve?the?purpose?of?improving?the overflow?capacity?of?the?water?conveyance?system. ??????Numerical?calculations?were?carried?out?for?11?options?of?reducing?the?weir?height?of?water?keeping?weirs,?and the?flow?velocity?vector?distribution?and?the?extent?of?the?annular?vortex?zone?in?the?weir?section?as?well?as?the variation ?of ?turbulent ?kinetic ?energy ?dissipation ?and ?overflow ?flow ?were ?analyzed. ?The ?results ?show ?that ?the overflow?of?the?water?conveyance?system?can?be?enhanced?by?the?weir?reduction?scheme,?and?by?compared?between different?weir?height?schemes,?the?optimal?weir?height?interval?that?increases?its?overflow?capacity?is?finally?found?to be?[1.0?P1≥P≥0.7P1]?(where?P is?water?keeping?weir?height).?When?the?weir?height?is?within?this?range,?the compression?effect?on?the?high?velocity?flow?area?is?weakened?by?lowering?P,?resulting?in?smaller?flow?vector elevation?angle?in?front?of?the?weir?and?the?annular?vortex?zone?behind?the?weir,?and?significantly?lower?energy dissipation,?lowering?0.1P1?flow?rate?increases?by?2.1%?on?average,?where?the?weir?height?P?is?lowered?to?0.7P1 when?the?flow?rate?is?increased?up?to?6.3%,?which?can?basically?meet?the?water?demand?requirements?of?the?project; Outside?this?interval,?although?lowering?P?reduces?the?annular?vortex?zone?after?the?weir?and?the?flow?velocity?vector angle?becomes?smaller,?the?energy?dissipation?is?reduced,?but?the?rapid?expansion?of?the?annular?vortex?zone?before the?weir?consumes?part?of?the?water?flow?energy,?resulting?in?the?flow?lift?decay,?at?this?time,?lowering?0.1P1?flow rate?only?increases?by?0.5%?on?average.?In?consideration?of?the?project?modification?cost?and?the?effect?of?overflow capacity ?enhancement, ?the ?structure ?of ?the ?water ?keeping ?weir ?is ?modified ?in ?the ?optimal ?weir ?height ?interval proposed??to?provide?reference?for?the?overflow?capacity?enhancement?of?the?water?transmission?system.
Water?keeping?weir?is?a?new?type?of?overflow?weir,?characterized?by?small?pressure?in?two?sections?of?the transmission?line,?and?simple?hydraulic?control.?In?order?to?enhance?the?water?conveyance?capacity?of?water?keeping weir?in?large?water?diversion?projects.?First?of?all,?based?on?the?actual?operation?of?the?project,?the?RNG?k-ε?turbulent flow?model?is?used?to?close?the?control?equations?and?establish?a?three-dimensional?isometric?numerical?simulation model?of?the?water?keeping?weir,?and?the?simulated?head?and?flow?velocity?of?the?pressure?measuring?tube?are?in good?agreement?with?the?measured?data,?and?on?the?premise?of?ensuring?the?accuracy?of?the?flow?pattern?in?the simulated?water?keeping?weir,?the?influence?of?the?water?keeping?weir?body?parameters?on?the?over-flow?capacity?of the?box?culvert?-?water?keeping?weir?water?conveyance?system?is?investigated.?It?revealed?the?mechanism?of?the generation?and?development?of?annular?vortex?zones?in?the?weir?section,?and?determined?that?the?dispersion?of?high velocity?water?flow?zone?caused?by?the?height?of?the?water?keeping?weir?and?the?presence?of?annular?vortex?zones are?the?main?bottlenecks?affecting?the?improvement?of?flow?capacity.?Thus,?the?proposed?solution?of?reducing?the height?of?the?water?keeping?weir?concentrate?the?high?velocity?water?flow?zone?and?reduce?the?scope?of?the?annular vortex?zone?to?reduce?the?energy?dissipation?in?the?weir?section,?so?as?to?achieve?the?purpose?of?improving?the overflow?capacity?of?the?water?conveyance?system. ??????Numerical?calculations?were?carried?out?for?11?options?of?reducing?the?weir?height?of?water?keeping?weirs,?and the?flow?velocity?vector?distribution?and?the?extent?of?the?annular?vortex?zone?in?the?weir?section?as?well?as?the variation ?of ?turbulent ?kinetic ?energy ?dissipation ?and ?overflow ?flow ?were ?analyzed. ?The ?results ?show ?that ?the overflow?of?the?water?conveyance?system?can?be?enhanced?by?the?weir?reduction?scheme,?and?by?compared?between different?weir?height?schemes,?the?optimal?weir?height?interval?that?increases?its?overflow?capacity?is?finally?found?to be?[1.0?P1≥P≥0.7P1]?(where?P is?water?keeping?weir?height).?When?the?weir?height?is?within?this?range,?the compression?effect?on?the?high?velocity?flow?area?is?weakened?by?lowering?P,?resulting?in?smaller?flow?vector elevation?angle?in?front?of?the?weir?and?the?annular?vortex?zone?behind?the?weir,?and?significantly?lower?energy dissipation,?lowering?0.1P1?flow?rate?increases?by?2.1%?on?average,?where?the?weir?height?P?is?lowered?to?0.7P1 when?the?flow?rate?is?increased?up?to?6.3%,?which?can?basically?meet?the?water?demand?requirements?of?the?project; Outside?this?interval,?although?lowering?P?reduces?the?annular?vortex?zone?after?the?weir?and?the?flow?velocity?vector angle?becomes?smaller,?the?energy?dissipation?is?reduced,?but?the?rapid?expansion?of?the?annular?vortex?zone?before the?weir?consumes?part?of?the?water?flow?energy,?resulting?in?the?flow?lift?decay,?at?this?time,?lowering?0.1P1?flow rate?only?increases?by?0.5%?on?average.?In?consideration?of?the?project?modification?cost?and?the?effect?of?overflow capacity ?enhancement, ?the ?structure ?of ?the ?water ?keeping ?weir ?is ?modified ?in ?the ?optimal ?weir ?height ?interval proposed??to?provide?reference?for?the?overflow?capacity?enhancement?of?the?water?transmission?system.
Abstract:
The?western?region?of?China?is?rich?in?hydropower?resources,?but?strong?earthquakes?occur?frequently. Hydraulic?structures?may?withstand?strong?earthquakes?during?their?life?cycle.?The?damage?caused?by?earthquakes will?affect?the?normal?operation?of?water?conservancy?projects,?which?seriously?threatens?people's?lives?and?social stability.?The?seismic?vulnerability?analysis?provides?the?seismic?basis?for?seismic?design?of?hydraulic?structure?and earthquake ?prevention ?and ?disaster ?reduction, ?which ?is ?very ?important ?to ?ensure ?the ?expected ?performance ?of concrete?gravity?dam?and?safe?operation?under?earthquake. ??????The?seismic?vulnerability?assessment?of?dams?often?requires?the?use?of?nonlinear?numerical?simulation?methods and?a?huge?amount?of?calculation?work.?Considering?the?efficiency?and?accuracy?of?seismic?vulnerability?assessment of ?dams, ?a ?way ?based ?on ?incremental ?dynamic ?analysis ?and ?multilayer ?perceptron ?for ?seismic ?vulnerability assessment?of?concrete?dams?is?proposed.?Taking?a?concrete?gravity?dam?in?northwest?China?as?an?example,?a?three- dimensional ?finite ?element ?model ?of ?dam ?body-reservoir ?water-foundation ?is ?established ?and ?multiple ?seismic response?calculations?are?carried?out.?The?selected?ground?motion?records?are?processed?by?equal?step?amplitude modulation,?and?the?amplitude?input?is?carried?out?by?three-way?seismic.?The?peak?ground?acceleration?is?selected?as the?index?of?ground?motion?intensity,?and?the?displacement?of?dam?top?along?river?is?selected?as?the?index?of?dam damage. ?The ?multilayer ?perceptron ?model ?was ?trained ?and ?tested ?by ?extracting ?the ?vibration ?characteristic parameters?as?input?and?the?displacement?of?dam?top?along?river?as?output.?The?ground?motion?is?extended?to?obtain the?vibration?characteristic?parameters.?The?MLP?model?is?used?to?quickly?predict?the?displacement?of?the?dam?top along?the?river,?and?the?finite?element?results?are?extended.?The?vulnerability?analysis?of?the?concrete?dam?is?carried out,?and?the?vulnerability?curve?is?drawn. ??????The ?results ?are ?as ?follows: ?(1) ?The ?seismic ?vulnerability ?of ?concrete ?gravity ?dam ?is ?analyzed ?based ?on incremental?dynamic?analysis?method.?Incremental?dynamic?analysis's?curve?clusters?of?river-side?displacement, transverse?river?flow?displacement?and?vertical?displacement?of?the?dam?crest?are?plotted,?and?seismic?vulnerability curves?are?plotted.?In?summary,?the?earthquake?damage?grade?of?the?selected?gravity?dam?under?the?designed?ground motion?is?low,?and?about?80%?probability?belongs?to?the?basically?intact?state.?(2)?The?multi-layer?perceptron?model is ?introduced ?into ?the ?incremental ?dynamic ?analysis ?method, ?and ?the ?seismic ?vulnerability ?analysis ?method ?of concrete?gravity?dam?based?on?incremental?dynamic?analysis-multi-layer?perceptron?is?proposed.?After?the?training of?the?multi-layer?perceptron?model,?the?accuracy?of?the?damage?prediction?index?is?higher.?The?coefficient?of determination?is?0.960?2,?the?mean?square?error?is?0.005?6,?and?the?mean?absolute?error?is?0.056?1.?Based?on?this method,?more?analytical?data?can?be?constructed?to?expand?the?finite?element?dynamic?calculation?results.?It?saves the?calculation?work?up?to?75%?and?reduces?the?nonlinear?dynamic?calculation?time.?The?seismic?vulnerability?of dams?can?be?predicted?quickly?and?accurately?as?close?as?possible?to?the?reality,?and?the?vulnerability?curve?can?be drawn?to?improve?the?efficiency?of?seismic?vulnerability?analysis?of?dams.
The?western?region?of?China?is?rich?in?hydropower?resources,?but?strong?earthquakes?occur?frequently. Hydraulic?structures?may?withstand?strong?earthquakes?during?their?life?cycle.?The?damage?caused?by?earthquakes will?affect?the?normal?operation?of?water?conservancy?projects,?which?seriously?threatens?people's?lives?and?social stability.?The?seismic?vulnerability?analysis?provides?the?seismic?basis?for?seismic?design?of?hydraulic?structure?and earthquake ?prevention ?and ?disaster ?reduction, ?which ?is ?very ?important ?to ?ensure ?the ?expected ?performance ?of concrete?gravity?dam?and?safe?operation?under?earthquake. ??????The?seismic?vulnerability?assessment?of?dams?often?requires?the?use?of?nonlinear?numerical?simulation?methods and?a?huge?amount?of?calculation?work.?Considering?the?efficiency?and?accuracy?of?seismic?vulnerability?assessment of ?dams, ?a ?way ?based ?on ?incremental ?dynamic ?analysis ?and ?multilayer ?perceptron ?for ?seismic ?vulnerability assessment?of?concrete?dams?is?proposed.?Taking?a?concrete?gravity?dam?in?northwest?China?as?an?example,?a?three- dimensional ?finite ?element ?model ?of ?dam ?body-reservoir ?water-foundation ?is ?established ?and ?multiple ?seismic response?calculations?are?carried?out.?The?selected?ground?motion?records?are?processed?by?equal?step?amplitude modulation,?and?the?amplitude?input?is?carried?out?by?three-way?seismic.?The?peak?ground?acceleration?is?selected?as the?index?of?ground?motion?intensity,?and?the?displacement?of?dam?top?along?river?is?selected?as?the?index?of?dam damage. ?The ?multilayer ?perceptron ?model ?was ?trained ?and ?tested ?by ?extracting ?the ?vibration ?characteristic parameters?as?input?and?the?displacement?of?dam?top?along?river?as?output.?The?ground?motion?is?extended?to?obtain the?vibration?characteristic?parameters.?The?MLP?model?is?used?to?quickly?predict?the?displacement?of?the?dam?top along?the?river,?and?the?finite?element?results?are?extended.?The?vulnerability?analysis?of?the?concrete?dam?is?carried out,?and?the?vulnerability?curve?is?drawn. ??????The ?results ?are ?as ?follows: ?(1) ?The ?seismic ?vulnerability ?of ?concrete ?gravity ?dam ?is ?analyzed ?based ?on incremental?dynamic?analysis?method.?Incremental?dynamic?analysis's?curve?clusters?of?river-side?displacement, transverse?river?flow?displacement?and?vertical?displacement?of?the?dam?crest?are?plotted,?and?seismic?vulnerability curves?are?plotted.?In?summary,?the?earthquake?damage?grade?of?the?selected?gravity?dam?under?the?designed?ground motion?is?low,?and?about?80%?probability?belongs?to?the?basically?intact?state.?(2)?The?multi-layer?perceptron?model is ?introduced ?into ?the ?incremental ?dynamic ?analysis ?method, ?and ?the ?seismic ?vulnerability ?analysis ?method ?of concrete?gravity?dam?based?on?incremental?dynamic?analysis-multi-layer?perceptron?is?proposed.?After?the?training of?the?multi-layer?perceptron?model,?the?accuracy?of?the?damage?prediction?index?is?higher.?The?coefficient?of determination?is?0.960?2,?the?mean?square?error?is?0.005?6,?and?the?mean?absolute?error?is?0.056?1.?Based?on?this method,?more?analytical?data?can?be?constructed?to?expand?the?finite?element?dynamic?calculation?results.?It?saves the?calculation?work?up?to?75%?and?reduces?the?nonlinear?dynamic?calculation?time.?The?seismic?vulnerability?of dams?can?be?predicted?quickly?and?accurately?as?close?as?possible?to?the?reality,?and?the?vulnerability?curve?can?be drawn?to?improve?the?efficiency?of?seismic?vulnerability?analysis?of?dams.
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Display Method:
Abstract:
The Middle Route of South to North Water Diversion Project (MRP) has long canals, involves many areas and hydraulic structures, transfers water by a huge amount, and has various working conditions. These all bring great difficulties to the regulation, control, and management of the project. The technical problem of the engineering lies in the fact that the scientific and mechanism problems behind it are not fully revealed and solved, including multi-dimensional equilibrium control mechanism of multiple water sources under changing conditions, multi-process coupling mechanism of water quantity and water quality, emergency scheduling model for multi-material water pollution, hydraulic response mechanism and control of open channel under multi-gate joint application. In order to establish a complete set of technical system to support its scheduling, this paper summarizes the existing research on the five key points of forecast, scheduling, simulation, control, and evaluation. And on the basis of summarizing the previous research, the key technologies awaiting urgent research are explained in detail, including forecast and scheduling in water source areas and water-receiving areas, multi-phase simulation of water pollution, water quality and water quality control, automatic control technology, evaluation technology, and platform construction. Finally, the paper discusses the scientific problems to be solved in order to realize the intelligent regulation and emergency regulation for the MRP and makes a summary of the research.
The Middle Route of South to North Water Diversion Project (MRP) has long canals, involves many areas and hydraulic structures, transfers water by a huge amount, and has various working conditions. These all bring great difficulties to the regulation, control, and management of the project. The technical problem of the engineering lies in the fact that the scientific and mechanism problems behind it are not fully revealed and solved, including multi-dimensional equilibrium control mechanism of multiple water sources under changing conditions, multi-process coupling mechanism of water quantity and water quality, emergency scheduling model for multi-material water pollution, hydraulic response mechanism and control of open channel under multi-gate joint application. In order to establish a complete set of technical system to support its scheduling, this paper summarizes the existing research on the five key points of forecast, scheduling, simulation, control, and evaluation. And on the basis of summarizing the previous research, the key technologies awaiting urgent research are explained in detail, including forecast and scheduling in water source areas and water-receiving areas, multi-phase simulation of water pollution, water quality and water quality control, automatic control technology, evaluation technology, and platform construction. Finally, the paper discusses the scientific problems to be solved in order to realize the intelligent regulation and emergency regulation for the MRP and makes a summary of the research.
Abstract:
Based on the T OE theor et ical fr amewo rk ( T echnolo gy2 Or ganizatio n2Environment) and the specific situation of smart water co nstr uction, the TOE framew ork w hich affects smart water constructio n was developed, and the effect s of each impact facto r o n the construction and development o f smar t w ater wer e analyzed from the technical, o rg anizat ional, and env iro nmental dimensions. T he technical dimensio n factors include the technica l superio rity, complex it y, compatibility , and o bser vability. T he org anizational dimension factor s include the const ruction necessity, demand urg ency , and co nstr uction feasibility . The envir on2 mental dimension factor s include the support sy st em, standard system, and info rmation securit y. On the basis, analyt ic hierarchy pr ocess ( AH P) w as used to determine the pr ior ity of the impact facto rs. The results showed that the or ganizatio nal dimensio n facto rs and technical dimension fact ors have hig h impacts on smart water construction w ith the weig ht o f 49% and 31% o ver the index system respect ively. Amo ng the impact factor s, const ruct ion necessity has the hig hest weig ht ( 25%) , follow ed by technical super io rit y ( 16%) , demand urg ency ( 12%) , and construction feasibility ( 12%) . The r esear ch pr ov ides an effectiv ely new metho d fo r the quantitative analy sis of impact factor s of smar t w ater const ruct ion, and the evaluation r esult s can prov ide import ant r eference fo r decision2making of w ater secto r and develo pment of w ater business.
Based on the T OE theor et ical fr amewo rk ( T echnolo gy2 Or ganizatio n2Environment) and the specific situation of smart water co nstr uction, the TOE framew ork w hich affects smart water constructio n was developed, and the effect s of each impact facto r o n the construction and development o f smar t w ater wer e analyzed from the technical, o rg anizat ional, and env iro nmental dimensions. T he technical dimensio n factors include the technica l superio rity, complex it y, compatibility , and o bser vability. T he org anizational dimension factor s include the const ruction necessity, demand urg ency , and co nstr uction feasibility . The envir on2 mental dimension factor s include the support sy st em, standard system, and info rmation securit y. On the basis, analyt ic hierarchy pr ocess ( AH P) w as used to determine the pr ior ity of the impact facto rs. The results showed that the or ganizatio nal dimensio n facto rs and technical dimension fact ors have hig h impacts on smart water construction w ith the weig ht o f 49% and 31% o ver the index system respect ively. Amo ng the impact factor s, const ruct ion necessity has the hig hest weig ht ( 25%) , follow ed by technical super io rit y ( 16%) , demand urg ency ( 12%) , and construction feasibility ( 12%) . The r esear ch pr ov ides an effectiv ely new metho d fo r the quantitative analy sis of impact factor s of smar t w ater const ruct ion, and the evaluation r esult s can prov ide import ant r eference fo r decision2making of w ater secto r and develo pment of w ater business.
Abstract:
Using precipitation and temperature for the period of 1851-2008 of Xi'an city, the paper analyzed the variation trends and abrupt changes of hydro-meteorological factors including precipitation and temperature using linear fitting, sliding t test, ordered clustering and Mann-Kendall methods．Firstly, the variation trends of precipitation and temperature were analyzed using linear fitting and anomaly percentage, and then the change characteristic of number of rainy days and precipitation were further analyzed. Finally, the paper investigated the abrupt changes of precipitation and temperature using sliding t test, ordered clustering and Mann-Kendall methods. The results showed that the precipitation decreased gradually. Precipitation accounts for 58% of annual precipitation during the flood season and the annual precipitation distribution is uneven. The annual mean temperature and extreme minimum temperature have increased. The abrupt changes of the precipitation were detected in 1958、1975 and 1980, and the abrupt changes of annual average temperature have found between 1993-1995.
Using precipitation and temperature for the period of 1851-2008 of Xi'an city, the paper analyzed the variation trends and abrupt changes of hydro-meteorological factors including precipitation and temperature using linear fitting, sliding t test, ordered clustering and Mann-Kendall methods．Firstly, the variation trends of precipitation and temperature were analyzed using linear fitting and anomaly percentage, and then the change characteristic of number of rainy days and precipitation were further analyzed. Finally, the paper investigated the abrupt changes of precipitation and temperature using sliding t test, ordered clustering and Mann-Kendall methods. The results showed that the precipitation decreased gradually. Precipitation accounts for 58% of annual precipitation during the flood season and the annual precipitation distribution is uneven. The annual mean temperature and extreme minimum temperature have increased. The abrupt changes of the precipitation were detected in 1958、1975 and 1980, and the abrupt changes of annual average temperature have found between 1993-1995.
Abstract:
"National River Linking Project (NRLP)" is a large-scale hydraulic engineering project that aims to reduce the persistent water shortage problems in India. In, this paper, describes the target planning and progress of the NRLPNational River Linking Project, was described, and introduces the program’s management system of this project and water policy in India was introduced. Due to the large scale of the project, it involves involved the deployment and utilization of water resources and utilization inof the many rivers of the South Peninsula, therefore several problems exist in the implementation of the project such as the funding stress, international development of transboundary rivers, and ecological environment. this paper addresses and analyzes the basic problems based on the project’s main benefit goals.
"National River Linking Project (NRLP)" is a large-scale hydraulic engineering project that aims to reduce the persistent water shortage problems in India. In, this paper, describes the target planning and progress of the NRLPNational River Linking Project, was described, and introduces the program’s management system of this project and water policy in India was introduced. Due to the large scale of the project, it involves involved the deployment and utilization of water resources and utilization inof the many rivers of the South Peninsula, therefore several problems exist in the implementation of the project such as the funding stress, international development of transboundary rivers, and ecological environment. this paper addresses and analyzes the basic problems based on the project’s main benefit goals.
Abstract:
Accurate and rapid determination of the distribution of contaminants is the main task for the investigation work of a contaminated site. As a new surveying tool for contaminated sites, direct push technology can be used for soil sample collection in the vadoze zone and aquifer, detection of aquifer parameters, and determination of pollutants. It has the advantages of fast, accurate, and free of cross-contamination. In this paper, the development and research progress of direct push technology was introduced, and the technology innovation was discussed.
Accurate and rapid determination of the distribution of contaminants is the main task for the investigation work of a contaminated site. As a new surveying tool for contaminated sites, direct push technology can be used for soil sample collection in the vadoze zone and aquifer, detection of aquifer parameters, and determination of pollutants. It has the advantages of fast, accurate, and free of cross-contamination. In this paper, the development and research progress of direct push technology was introduced, and the technology innovation was discussed.
Abstract:
Sensitivity analysis was performed to analyze the inputs and outputs of the complex model and system qualitatively and quantitatively, which can benefit the inspection of model structure, identification of model parameters, and model application. In this paper, Sobol method was applied to evaluate the sensitivity of single parameter and multiple parameters of the model in the Huanren reservoir catchment. The objective functions of sensitivity analysis included the deterministic coefficients and error coefficients of total water, low flow, and high flow. The results showed that the sensitivity of parameters was different under different objective functions, and Sobol method can provide the sensitivity for all parameters and sensitivity between each parameter, which is useful for sensitivity analysis of hydrological models.
Sensitivity analysis was performed to analyze the inputs and outputs of the complex model and system qualitatively and quantitatively, which can benefit the inspection of model structure, identification of model parameters, and model application. In this paper, Sobol method was applied to evaluate the sensitivity of single parameter and multiple parameters of the model in the Huanren reservoir catchment. The objective functions of sensitivity analysis included the deterministic coefficients and error coefficients of total water, low flow, and high flow. The results showed that the sensitivity of parameters was different under different objective functions, and Sobol method can provide the sensitivity for all parameters and sensitivity between each parameter, which is useful for sensitivity analysis of hydrological models.
Abstract:
The analysis of the night minimum flow data in the Districted Metered Area (DMA) of the water distribution system can characterize the real loss of DMA. The high-frequency and high-accuracy measured night flow data were analyzed, which indicated that the night flow data of DMA at different time periods are in normal distribution and the lowest night flow data is close to the real loss of DMA. In this study, the minimum night flow data from 2 AM to 4 AM in the early morning were analyzed based on the confidence level of 95.5% and confidence interval of (m-2d, m+2d).. The results showed that the minimum night flow of DMA after removing the abnormal values characterized by m-2dcan eliminate the effects of error and interference of measured data, and therefore obtain the real loss of DMA. This method can lower the evaluation error of night water demand, and facilitate the in-situ meter flow measurement to assess the DMA leakage level quickly.
The analysis of the night minimum flow data in the Districted Metered Area (DMA) of the water distribution system can characterize the real loss of DMA. The high-frequency and high-accuracy measured night flow data were analyzed, which indicated that the night flow data of DMA at different time periods are in normal distribution and the lowest night flow data is close to the real loss of DMA. In this study, the minimum night flow data from 2 AM to 4 AM in the early morning were analyzed based on the confidence level of 95.5% and confidence interval of (m-2d, m+2d).. The results showed that the minimum night flow of DMA after removing the abnormal values characterized by m-2dcan eliminate the effects of error and interference of measured data, and therefore obtain the real loss of DMA. This method can lower the evaluation error of night water demand, and facilitate the in-situ meter flow measurement to assess the DMA leakage level quickly.
Abstract:
Environmental Kuznets Curve (EKC) hypothesis has instructive significance to explore the relationship between environmental protection and economic development and to seek the coordinated development of economy and environment. Based on the analysis of the basic conception of EKC hypothesis, the research progress of the impact factors, theoretical developments, and empirical studies of EKC were illustrated in this paper, and the existing problems of the hypothesis were also discussed. Finally, it was noted that under the international trade conditions, the developing countries should study the clean technology, policy reformation, public education, and environmental law system from the developed countries, which can help them decrease the EKC turn point, flatten EKC curve, and seek for win-win relationship between economy and environment.
Environmental Kuznets Curve (EKC) hypothesis has instructive significance to explore the relationship between environmental protection and economic development and to seek the coordinated development of economy and environment. Based on the analysis of the basic conception of EKC hypothesis, the research progress of the impact factors, theoretical developments, and empirical studies of EKC were illustrated in this paper, and the existing problems of the hypothesis were also discussed. Finally, it was noted that under the international trade conditions, the developing countries should study the clean technology, policy reformation, public education, and environmental law system from the developed countries, which can help them decrease the EKC turn point, flatten EKC curve, and seek for win-win relationship between economy and environment.
Abstract:
Compared with the traditional determined hydrologic forecast, hydrologic ensemble forecast contains various uncertainties in the hydrologic forecast processes. Therefore, the accuracy and validity of hydrologic forecast have been improved theoretically. Meanwhile, the cognitive and predictive capabilities of the events such as storm, flood, and drought have been enhanced in the practical applications. The hydrologic ensemble forecast can provide more accurate and useful information in flood control, drought relief, and sustainable water resources management. In this paper, we firstly reviewed the history of hydrologic ensemble forecast, and then we summarized the research progresses in theory, methods, as well as the applications and operational hydrologic ensemble forecast. We focused on two research aspects of the pre-processing and post-processing issues in an effort to provide a useful platform for the development of hydrologic ensemble prediction. The perspectives and recommendations on this subject were provided. This paper is of important significance in the future development of hydrologic ensemble forecast research.
Compared with the traditional determined hydrologic forecast, hydrologic ensemble forecast contains various uncertainties in the hydrologic forecast processes. Therefore, the accuracy and validity of hydrologic forecast have been improved theoretically. Meanwhile, the cognitive and predictive capabilities of the events such as storm, flood, and drought have been enhanced in the practical applications. The hydrologic ensemble forecast can provide more accurate and useful information in flood control, drought relief, and sustainable water resources management. In this paper, we firstly reviewed the history of hydrologic ensemble forecast, and then we summarized the research progresses in theory, methods, as well as the applications and operational hydrologic ensemble forecast. We focused on two research aspects of the pre-processing and post-processing issues in an effort to provide a useful platform for the development of hydrologic ensemble prediction. The perspectives and recommendations on this subject were provided. This paper is of important significance in the future development of hydrologic ensemble forecast research.
Abstract:
Based on the daily data of precipitation and temperature of 30 basic meteorological stations during the period 1956-2010, twelve indices characterizing extreme climate change have been selected to analyze the temporal changes in precipitation and temperature extremes in the Hai River Basin. As per many other parts of the world, the analysis shows an increase in the intensity, frequency and duration of high temperature extremes and a decrease in that of cold extremes. The intensity of short-time precipitation extremes shows an increase and the frequency of heavy precipitation shows a decrease. The consecutive wet days shows a decrease, while the consecutive dry days shows an increase in recent decades, thus the dry pattern has been aggravated in the basin. The annual high temperature extremes and short-time precipitation extremes have begun to frequently occur since 1990s from interdecadal variations, the rainfall of long-duration precipitation events has shown a decrease however. The general warm and dry trend and precipitation concentration will have a negative impact on the agriculture production and water resources development. Meanwhile, the increase of short-time precipitation extremes may exacerbate the risk of local flood disaster in mountainous area as well as urban waterlogging.
Based on the daily data of precipitation and temperature of 30 basic meteorological stations during the period 1956-2010, twelve indices characterizing extreme climate change have been selected to analyze the temporal changes in precipitation and temperature extremes in the Hai River Basin. As per many other parts of the world, the analysis shows an increase in the intensity, frequency and duration of high temperature extremes and a decrease in that of cold extremes. The intensity of short-time precipitation extremes shows an increase and the frequency of heavy precipitation shows a decrease. The consecutive wet days shows a decrease, while the consecutive dry days shows an increase in recent decades, thus the dry pattern has been aggravated in the basin. The annual high temperature extremes and short-time precipitation extremes have begun to frequently occur since 1990s from interdecadal variations, the rainfall of long-duration precipitation events has shown a decrease however. The general warm and dry trend and precipitation concentration will have a negative impact on the agriculture production and water resources development. Meanwhile, the increase of short-time precipitation extremes may exacerbate the risk of local flood disaster in mountainous area as well as urban waterlogging.
Abstract:
As a quantitative indicator of drought, drought index plays an important role in the monitoring and forecasting of drought and water resources management, and it is also a useful research tool in the field of hydrology and water resources. Over the last decade, the primary progress in the development and improvement of drought index involved the introduction of evapotranspiration as a factor of the index calculation, which can improve the parameter accuracy in model simulation and combine with the model algorithm of hydrological process. The application of drought index included the inversion and prediction of regional drought, crop yield prediction, forest fire detection, and paleoclimate reconstruction. The development and application of drought index provided an effective tool for regional drought monitoring and water resources management; however, the quantification and comprehensive evaluation of drought index should be considered as research priorities, which can help improve the accuracy and reliability of model monitoring and thus provide new options and technical approaches for rapid monitoring of drought.
As a quantitative indicator of drought, drought index plays an important role in the monitoring and forecasting of drought and water resources management, and it is also a useful research tool in the field of hydrology and water resources. Over the last decade, the primary progress in the development and improvement of drought index involved the introduction of evapotranspiration as a factor of the index calculation, which can improve the parameter accuracy in model simulation and combine with the model algorithm of hydrological process. The application of drought index included the inversion and prediction of regional drought, crop yield prediction, forest fire detection, and paleoclimate reconstruction. The development and application of drought index provided an effective tool for regional drought monitoring and water resources management; however, the quantification and comprehensive evaluation of drought index should be considered as research priorities, which can help improve the accuracy and reliability of model monitoring and thus provide new options and technical approaches for rapid monitoring of drought.
Abstract:
With the r apid development o f meso scale numer ical at mospher ic model WRF in r ecent y ears, its application is wider and w ider. In or der to ex plain the mechanism, r eveal the develo pment directio n and pr ov ide refer ence for r elated fields research2 er s, WRF model sy stem is int roduced, it is discussed that the influence o f parameterized phy sical pr ocesses, data assimilatio n and reasonable spat ial scale o n the simulation effect o f WRF model. Related studies have shown that: ( 1) differ ent par ameter2 ized phy sical processes need to be chosen in different reg ion and different time; ( 2) the common data assimilation method is 3DVar data assimilatio n at present, hybr id data assimilatio n may be a better met ho d to impr ove the simulatio n effect of WRF model; ( 3) reasonable spat ial scales need to be cho sen because not the hig her hor izo nt al reso lution, t he better simulat ion effect for a ll research; ( 4) WRF mo del has g oo d simulat ion effect , hig h pr ediction accuracy , there is mo re w ide applicat ion.
With the r apid development o f meso scale numer ical at mospher ic model WRF in r ecent y ears, its application is wider and w ider. In or der to ex plain the mechanism, r eveal the develo pment directio n and pr ov ide refer ence for r elated fields research2 er s, WRF model sy stem is int roduced, it is discussed that the influence o f parameterized phy sical pr ocesses, data assimilatio n and reasonable spat ial scale o n the simulation effect o f WRF model. Related studies have shown that: ( 1) differ ent par ameter2 ized phy sical processes need to be chosen in different reg ion and different time; ( 2) the common data assimilation method is 3DVar data assimilatio n at present, hybr id data assimilatio n may be a better met ho d to impr ove the simulatio n effect of WRF model; ( 3) reasonable spat ial scales need to be cho sen because not the hig her hor izo nt al reso lution, t he better simulat ion effect for a ll research; ( 4) WRF mo del has g oo d simulat ion effect , hig h pr ediction accuracy , there is mo re w ide applicat ion.
Abstract:
The objective of this study is to evaluate the applicability of SWAT model to agricultural drought evaluation for regions without or lack of soil moisture data. For this purpose, the SWAT model was applied to simulate the hydrological process in the Bahe watershed of the upper Weihe River. The soil water content was obtained and it was used to calculate the relative soil moisture. The calculated relative soil moisture was regarded as the evaluation index of agricultural drought. The results showed that severe spring droughts occurred in 2001 and 2002 and summer drought occurred in 2003 in the Bahe watershed, which was in accordance with the actual conditions. . Therefore, SWAT model is applicable to agricultural drought evaluation for the area lack of soil moisture data.
The objective of this study is to evaluate the applicability of SWAT model to agricultural drought evaluation for regions without or lack of soil moisture data. For this purpose, the SWAT model was applied to simulate the hydrological process in the Bahe watershed of the upper Weihe River. The soil water content was obtained and it was used to calculate the relative soil moisture. The calculated relative soil moisture was regarded as the evaluation index of agricultural drought. The results showed that severe spring droughts occurred in 2001 and 2002 and summer drought occurred in 2003 in the Bahe watershed, which was in accordance with the actual conditions. . Therefore, SWAT model is applicable to agricultural drought evaluation for the area lack of soil moisture data.
Abstract:
The instantaneous peak flow (IPF) is the basic information for hydraulic design，construction and management. It also has an important influence on the investment and safety of hydraulic structures. However, the IPF records in Tibet are generally short in length, while mean daily flow (MDF) records are relatively longer. In this study, the IPF records are extended by analyzing the relationship between corresponding IPF and MDF records. The results show that the ratio between IPF and MDF is stable in most of hydrological stations. The relative error between estimated IPF and observed IPF is less than 10%. The results of flood frequency analysis using extended IPF series are more reasonable than that using the measured IPF series. For the stations with limited measured MDF, the HIMS model is used to extend the available MDF. The HIMS model is applied in three representative rivers of Tibet: the Nianchu river, Lhasa river and Niang river. The results show that the model has a good performance in both daily and peak flow simulation. The end year of IPF series in the three representative hydrological stations has been extended from 2000 to 2010 by the simulation results of HIMS and the relationship between IPF and MDF.
The instantaneous peak flow (IPF) is the basic information for hydraulic design，construction and management. It also has an important influence on the investment and safety of hydraulic structures. However, the IPF records in Tibet are generally short in length, while mean daily flow (MDF) records are relatively longer. In this study, the IPF records are extended by analyzing the relationship between corresponding IPF and MDF records. The results show that the ratio between IPF and MDF is stable in most of hydrological stations. The relative error between estimated IPF and observed IPF is less than 10%. The results of flood frequency analysis using extended IPF series are more reasonable than that using the measured IPF series. For the stations with limited measured MDF, the HIMS model is used to extend the available MDF. The HIMS model is applied in three representative rivers of Tibet: the Nianchu river, Lhasa river and Niang river. The results show that the model has a good performance in both daily and peak flow simulation. The end year of IPF series in the three representative hydrological stations has been extended from 2000 to 2010 by the simulation results of HIMS and the relationship between IPF and MDF.
Abstract:
Static cone penetration test (CPT) as is an in situ test, which is was widely used in the engineering practice. Based on recently research results, thise paper systematically introduced sums up the research and development course in of CPT and summarized the research progress of the, such as instrument development, cone resistance theoretical research of cone resistance, model test, numerical simulation, and engineering application of CPT. Empirical formula of to calculate the soil parameters using CPT on for different industries and different areas were summarized. The paper pointed out that iIt is necessary to fully consider the engineering characteristics of regional soil when using in application of the CPT results. Moreover, It should be point out that the theoretical analysis of excess pore water pressure, analytic solution of cylindrical hole space problem, and numerical analysis simulation for large deformation analysis theory need to be further improved..
Static cone penetration test (CPT) as is an in situ test, which is was widely used in the engineering practice. Based on recently research results, thise paper systematically introduced sums up the research and development course in of CPT and summarized the research progress of the, such as instrument development, cone resistance theoretical research of cone resistance, model test, numerical simulation, and engineering application of CPT. Empirical formula of to calculate the soil parameters using CPT on for different industries and different areas were summarized. The paper pointed out that iIt is necessary to fully consider the engineering characteristics of regional soil when using in application of the CPT results. Moreover, It should be point out that the theoretical analysis of excess pore water pressure, analytic solution of cylindrical hole space problem, and numerical analysis simulation for large deformation analysis theory need to be further improved..
Abstract:
Wetlands and aAtmosphere constantly engaged in the exchange of energy and material constantly, that is , free water surface of wetland and dense vegetation was are in the process of evapotranspirationthrough evapo-transpiration to enter into the atmosphere and a part of water returns to the groundwater as precipitation, thereby increasing the so that water vapour injected into the atmosphere， then formed the rain and returned to the ground, thereby it improved local humidity and precipitation. In this paper, Based on the precipitation data from 1974～2010 of Hengshui Lake and twenty- four24 nearby rRainfall sStations from 1974 to 2010 were used to calculate of periphery ， this article figured out the average precipitation of the Hengshui Lake District ，10- km radius affected zone, 10～2010- to 20- km circular affected zone， and 20- to～30- km circular affected zone. It analyzed theThe effects of the wetland of Hengshui Lake on precipitation were analyzed, and the main reasons were investigated based on the change regularity of different affected zone of Hengshui Lake wetland, and explore the main reason through precipitation formation mechanism of precipitation. The result showsed: that the precipitation decreases Hengshui Lake wetland from the near to the distant distance of the Hengshui Lake Wetland, indicating was obviously decreasing, it revealed that Hengshui Lake wetland has an adjustment function the adjustment effects of the wetland onto the climate of surrounding regional climatearea.
Wetlands and aAtmosphere constantly engaged in the exchange of energy and material constantly, that is , free water surface of wetland and dense vegetation was are in the process of evapotranspirationthrough evapo-transpiration to enter into the atmosphere and a part of water returns to the groundwater as precipitation, thereby increasing the so that water vapour injected into the atmosphere， then formed the rain and returned to the ground, thereby it improved local humidity and precipitation. In this paper, Based on the precipitation data from 1974～2010 of Hengshui Lake and twenty- four24 nearby rRainfall sStations from 1974 to 2010 were used to calculate of periphery ， this article figured out the average precipitation of the Hengshui Lake District ，10- km radius affected zone, 10～2010- to 20- km circular affected zone， and 20- to～30- km circular affected zone. It analyzed theThe effects of the wetland of Hengshui Lake on precipitation were analyzed, and the main reasons were investigated based on the change regularity of different affected zone of Hengshui Lake wetland, and explore the main reason through precipitation formation mechanism of precipitation. The result showsed: that the precipitation decreases Hengshui Lake wetland from the near to the distant distance of the Hengshui Lake Wetland, indicating was obviously decreasing, it revealed that Hengshui Lake wetland has an adjustment function the adjustment effects of the wetland onto the climate of surrounding regional climatearea.
Abstract:
Based on the monthly precipitation data of 25 meteorological stations in the Haihe River Basin from 1960 to 2010, the inter 2annual precipitation characteristics in the Haihe River Basin were analyzed using the linear regression and cumulative a 2 nomaly curve methods. T he probability distribution of precipitation was analyzed using the Pearson III curve method, and the spatial variation of precipitation was analyzed using the spatial interpolation method. T he results showed that (1) precipitation in the Haihe River Basin has a slightly decreasing trend in recent 51 years, and the decreasing trend is stable recently; ( 2) there is a trend with more wet years while less dry years in the Haihe River Basin and the trend is increasing; (3) seasonal variation of precipitation is obvious; and (4) precipitation decreases trend from the south to the north.
Based on the monthly precipitation data of 25 meteorological stations in the Haihe River Basin from 1960 to 2010, the inter 2annual precipitation characteristics in the Haihe River Basin were analyzed using the linear regression and cumulative a 2 nomaly curve methods. T he probability distribution of precipitation was analyzed using the Pearson III curve method, and the spatial variation of precipitation was analyzed using the spatial interpolation method. T he results showed that (1) precipitation in the Haihe River Basin has a slightly decreasing trend in recent 51 years, and the decreasing trend is stable recently; ( 2) there is a trend with more wet years while less dry years in the Haihe River Basin and the trend is increasing; (3) seasonal variation of precipitation is obvious; and (4) precipitation decreases trend from the south to the north.
Abstract:
A proposed water transfer tunnel will be excavated with tunnel boring machine (TBM) in the surrounding type-III rock. The shotcrete and reinforced concrete segment serve as the initial support and permanent liner, respectively. The considerable internal and external water pressures are loaded on the liner, with the water head values of 110 m and 200 m, respectively. In this paper, in consideration of the contact relationship between segments, the contact relationship between segment and surrounding structure, and the cooperative working performance of reinforcement bars and concrete, the stress deformation characteristics of the liner under high water pressures are analyzed using the finite element method. The results showed that the external water pressure is the decisive load for the design of tunnel liner, and therefore a simplified model of segment liner design was proposed. The results suggested that it is feasible to use the reinforced concrete segment as tunnel lining under the conditions of the surrounding rock, support, and water pressure shown in the study.
A proposed water transfer tunnel will be excavated with tunnel boring machine (TBM) in the surrounding type-III rock. The shotcrete and reinforced concrete segment serve as the initial support and permanent liner, respectively. The considerable internal and external water pressures are loaded on the liner, with the water head values of 110 m and 200 m, respectively. In this paper, in consideration of the contact relationship between segments, the contact relationship between segment and surrounding structure, and the cooperative working performance of reinforcement bars and concrete, the stress deformation characteristics of the liner under high water pressures are analyzed using the finite element method. The results showed that the external water pressure is the decisive load for the design of tunnel liner, and therefore a simplified model of segment liner design was proposed. The results suggested that it is feasible to use the reinforced concrete segment as tunnel lining under the conditions of the surrounding rock, support, and water pressure shown in the study.
Abstract:
The impacts of human activities and dry climate aggravate the water pollution and eutrophication in the Baiyang Lake. Through the analysis of hydro 2chemical compositions of the water, five indexes[Chla, TN, T P, COD Mn, and SD] , which are re 2 lated to water eutrophication, are selected as evaluation parameters, and the comprehensive nutrition index method is adopted to determine the water eutrophication type. T he results of water quality monitoring data show that the type of water is CNaII, and the lake is in mesotrophic or eutrophic state determined by the comprehensive nutrition index method. The principal component analysis results show that TP is the main factor to cause water pollution in the lake. According to the analysis of diatom and its combination, the diatom in the lake is characterized by the combination of eutrophic species Cyclotellameneghiniana ( 20. 43%) and Cyclostep hanos tholif ormis ( 25. 40%) , which indicates that the lake is in the eutrophication state and water environment is in danger.
The impacts of human activities and dry climate aggravate the water pollution and eutrophication in the Baiyang Lake. Through the analysis of hydro 2chemical compositions of the water, five indexes[Chla, TN, T P, COD Mn, and SD] , which are re 2 lated to water eutrophication, are selected as evaluation parameters, and the comprehensive nutrition index method is adopted to determine the water eutrophication type. T he results of water quality monitoring data show that the type of water is CNaII, and the lake is in mesotrophic or eutrophic state determined by the comprehensive nutrition index method. The principal component analysis results show that TP is the main factor to cause water pollution in the lake. According to the analysis of diatom and its combination, the diatom in the lake is characterized by the combination of eutrophic species Cyclotellameneghiniana ( 20. 43%) and Cyclostep hanos tholif ormis ( 25. 40%) , which indicates that the lake is in the eutrophication state and water environment is in danger.
Abstract:
Thro ug h the analysis of t he technique, envir onment, law , and eco nomy in the manag ement and operatio n o f inter2basin water transfer projects abro ad, this paper summar ized the successful ex per ience o f int er2basin w ater tr ansfer pr ojects in the wo rld fr om the aspects of leg islat ion, w ater r ig ht s, water pr ice, unified manag ement o f water resources, investment manag ement of eng ineering const ruct ion, and management o per ation mode, w hich can pro vide t he refer ence fo r the o per ation of inter2basin water transfer pro jects in China.
Thro ug h the analysis of t he technique, envir onment, law , and eco nomy in the manag ement and operatio n o f inter2basin water transfer projects abro ad, this paper summar ized the successful ex per ience o f int er2basin w ater tr ansfer pr ojects in the wo rld fr om the aspects of leg islat ion, w ater r ig ht s, water pr ice, unified manag ement o f water resources, investment manag ement of eng ineering const ruct ion, and management o per ation mode, w hich can pro vide t he refer ence fo r the o per ation of inter2basin water transfer pro jects in China.
Periodical information
Competent Authority:Department of Water Resources of Hebei Procince
Sponsored by:Hebei Institute of Water Resources
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