Volume 19,Issue 1,2021 Table of Contents
2021, 19(1):1-11.
Abstract:
Taking the International Food and Agriculture Organization(FAO) Penman-Monteith method(P-M method) as a benchmark, the study area is divided into 5 arid and humid regions based on humidity. From the four aspects of correlation, multi-year average, spatial distribution within the year, and parameter charact eristics, and 12 potential evaprtranspiration methods, including temperature method, mass transfer method, and radiation method, it is deeply divided into three types. The applicability of the estimat ion method was carried out in different climate zones in 31 provinces(aur tonomous regions and municipalities) in China. The results show that: with in the research area, the monthly correlation, and multi-year average potential eva potranspiration value between radiatior based methods and the P-M method is significantly better than tem perature based methods and mass-transfer-based methods, among them, the P-T method has the best estimation effect while the Hamon method has the worst; for different arid and humid regions, the correlation between temperature based methods and P-M method,mass-transfer-based methods, and P-M method is better in arid regions than in humid regions; the potential evapotranspiration estimated by the Penman method is closest to that calculated by the P-M method in arid regions; radiation-based-methods (excluding the Jensen method) are better than tem perature-based methods and mass-transfer-based methods in different arid and humid regions, rohwer method has the best annual distribution in all arid and humid regions.The Abtew method is the best in arid regions. PT,M ak, Harg, and Door metrods are best in humid regions,while the Jensen and Kharrufa methods are the worst in all arid and humid regions. Taken together, the radiation method performs best in the research area,when the study area is humid, temperature-based methods and mass-transfer- based methods are selected, if the study area is arid, Penman and A btew methods may be preferred.
Taking the International Food and Agriculture Organization(FAO) Penman-Monteith method(P-M method) as a benchmark, the study area is divided into 5 arid and humid regions based on humidity. From the four aspects of correlation, multi-year average, spatial distribution within the year, and parameter charact eristics, and 12 potential evaprtranspiration methods, including temperature method, mass transfer method, and radiation method, it is deeply divided into three types. The applicability of the estimat ion method was carried out in different climate zones in 31 provinces(aur tonomous regions and municipalities) in China. The results show that: with in the research area, the monthly correlation, and multi-year average potential eva potranspiration value between radiatior based methods and the P-M method is significantly better than tem perature based methods and mass-transfer-based methods, among them, the P-T method has the best estimation effect while the Hamon method has the worst; for different arid and humid regions, the correlation between temperature based methods and P-M method,mass-transfer-based methods, and P-M method is better in arid regions than in humid regions; the potential evapotranspiration estimated by the Penman method is closest to that calculated by the P-M method in arid regions; radiation-based-methods (excluding the Jensen method) are better than tem perature-based methods and mass-transfer-based methods in different arid and humid regions, rohwer method has the best annual distribution in all arid and humid regions.The Abtew method is the best in arid regions. PT,M ak, Harg, and Door metrods are best in humid regions,while the Jensen and Kharrufa methods are the worst in all arid and humid regions. Taken together, the radiation method performs best in the research area,when the study area is humid, temperature-based methods and mass-transfer- based methods are selected, if the study area is arid, Penman and A btew methods may be preferred.
2021, 19(1):12-35.
Abstract:
The background of real-time correction for flood forecasting is reviewed, and the research advances in real-time correction are summarized. On this basis, real-time correction was divided into two categories such as the terminal bias correction and process bias correction. The correction methods in these two approaches were sorted out, and the research results and progress were prsented. Five representative real-time correction algorithms,i.e., feedback simulation, autr-regressive(AR), recursive least squares(RLS), Kalman filtering(KF), and dynamic system response curve(DSRC),w ere introduced, and their characteristics and applicability were analyzed.The future development direction and research hotspots of real-time correction for flood forecasting were predicted.
The background of real-time correction for flood forecasting is reviewed, and the research advances in real-time correction are summarized. On this basis, real-time correction was divided into two categories such as the terminal bias correction and process bias correction. The correction methods in these two approaches were sorted out, and the research results and progress were prsented. Five representative real-time correction algorithms,i.e., feedback simulation, autr-regressive(AR), recursive least squares(RLS), Kalman filtering(KF), and dynamic system response curve(DSRC),w ere introduced, and their characteristics and applicability were analyzed.The future development direction and research hotspots of real-time correction for flood forecasting were predicted.
2021, 19(1):36-42.
Abstract:
Given the steady progress of water saving work in China, and based on the basic law of natural social dual water cycle, the process and influencing factors of water use in various industries in the Beijing-Tianjin-Hebei region are analyzed, and the ultimate water-saving potential of stock water is calculated from two aspects such as water-saving and resource-saving. The results show that: the water saving potential and resource water saving potential of the Beijing-Tianjin-H ebei region are 1.144 bilion m3 and 636 milion m3, respectively, accounting for 5.4% and 3.0% of the total regional water consumption, with limited water-saving potential; according to the analysis of different industries, the water-saving amount and resource water saving amount of agriculture accounted for 51.0% and 59.3% of the total water-saving amount, respectively, agriculture is still the focus of regional water-saving; judging from research results, the calculation method of ultimate water-saving potential proposed can scientifically and accurately calculate the water-saving potential of regional or basin stock users, calculate and clarify the wa ter-saving target, and provide a reference for regional water resources management.
Given the steady progress of water saving work in China, and based on the basic law of natural social dual water cycle, the process and influencing factors of water use in various industries in the Beijing-Tianjin-Hebei region are analyzed, and the ultimate water-saving potential of stock water is calculated from two aspects such as water-saving and resource-saving. The results show that: the water saving potential and resource water saving potential of the Beijing-Tianjin-H ebei region are 1.144 bilion m3 and 636 milion m3, respectively, accounting for 5.4% and 3.0% of the total regional water consumption, with limited water-saving potential; according to the analysis of different industries, the water-saving amount and resource water saving amount of agriculture accounted for 51.0% and 59.3% of the total water-saving amount, respectively, agriculture is still the focus of regional water-saving; judging from research results, the calculation method of ultimate water-saving potential proposed can scientifically and accurately calculate the water-saving potential of regional or basin stock users, calculate and clarify the wa ter-saving target, and provide a reference for regional water resources management.
2021, 19(1):43-49,82.
Abstract:
A hillside residential area in Jinan city is selected to study the main road of "road flood discharge"which is generalized as an irregular open channel, and the influence of sponge city reconstruction scheme on design rainfall hydrological process in different return periods based on the SWMM(stom water management model) model.The results show that: the SWMM model can be used to simulate the process of "flooding on road"in the hillside area, and the rainfalt-runoff process can be effectively ont rolled by the select ed modificat ion scheme(low impact development and drainage system reconstruction); for different return periods(1 year,3 years, and 5 years)w ithin 5 years,the redution rates of total runoff and peak flood discharge from Out01 and Out 02 are over 20% and 10%, respect ively, the peak water level reduction rate at Out 01 is greater than 15%, which significantly reduces the impact of the "road flood"disast er in the study area.This study can provide a theoretical basis and significant reference for the simulation of "flooding on road"and the construction and management of sponge cit ies in the hillside area.
A hillside residential area in Jinan city is selected to study the main road of "road flood discharge"which is generalized as an irregular open channel, and the influence of sponge city reconstruction scheme on design rainfall hydrological process in different return periods based on the SWMM(stom water management model) model.The results show that: the SWMM model can be used to simulate the process of "flooding on road"in the hillside area, and the rainfalt-runoff process can be effectively ont rolled by the select ed modificat ion scheme(low impact development and drainage system reconstruction); for different return periods(1 year,3 years, and 5 years)w ithin 5 years,the redution rates of total runoff and peak flood discharge from Out01 and Out 02 are over 20% and 10%, respect ively, the peak water level reduction rate at Out 01 is greater than 15%, which significantly reduces the impact of the "road flood"disast er in the study area.This study can provide a theoretical basis and significant reference for the simulation of "flooding on road"and the construction and management of sponge cit ies in the hillside area.
2021, 19(1):50-66.
Abstract:
Taking the water resources allocation project in the northern Hubei as the object, the multi-water source multi-objective optimal allo cation was studied under the background of a large-scale water transfer projet. The reservoirs in the northern Hubei are div ided into three types: filling reservoirs, compensation reservoirs, and online reservoirs. The water resources allocr tion project in the northern Hubei is systematically generalized according to the characteristics of various reservoirs.A multi-water source multi-objedive optimal allocation model is established with the minimum annual water shortage and the minimum water transfer cost as the objective function.The weight coefficient method is used to obtain the Pareto optimal set. The multi-objective decision-making method based on interval hesitant fuzzy language and TOPSIS is adopted to evaluate the water shortage and wat er transfer of each scheme and seled the optimal scheme. The results show that: for the water resources allocation project in the northern Hubei, the scheme with a weight ratio of water shortage to water transfer being 7:3 is the best in conrprehensive evaluation,which focuses on water shortage while the water transfer cost is taken into account; the multi-objective decision-making method of water resources based on interval hesitant fuzzy language set and TOPSIS has been proved to have high stability and feasibility by examples.
Taking the water resources allocation project in the northern Hubei as the object, the multi-water source multi-objective optimal allo cation was studied under the background of a large-scale water transfer projet. The reservoirs in the northern Hubei are div ided into three types: filling reservoirs, compensation reservoirs, and online reservoirs. The water resources allocr tion project in the northern Hubei is systematically generalized according to the characteristics of various reservoirs.A multi-water source multi-objedive optimal allocation model is established with the minimum annual water shortage and the minimum water transfer cost as the objective function.The weight coefficient method is used to obtain the Pareto optimal set. The multi-objective decision-making method based on interval hesitant fuzzy language and TOPSIS is adopted to evaluate the water shortage and wat er transfer of each scheme and seled the optimal scheme. The results show that: for the water resources allocation project in the northern Hubei, the scheme with a weight ratio of water shortage to water transfer being 7:3 is the best in conrprehensive evaluation,which focuses on water shortage while the water transfer cost is taken into account; the multi-objective decision-making method of water resources based on interval hesitant fuzzy language set and TOPSIS has been proved to have high stability and feasibility by examples.
2021, 19(1):67-74.
Abstract:
Based on clarifying the connotation of the healthy water cycle, five criterion layers covering water resources,water environment, water ecology, the water utility, and water disasters were constructed, including precipitation, per capita water resources, per mu water resources, and groundwater supply ratio. The water cycle health evaluation index system of other 18 indicators, using the combination of analytic hierarchy process and entropy met hod to assign weights and using fuzzy comprehensive evaluation method to evaluate the water cycle health status of the Beijing-Tianjin- Hebei region from 2009 to 2018.The evaluration results show that: the overall water cycle health in the Beijing-Tianjirn-Hebei region has gradually improved in the past ten years. The water cycle health levels in Beijing, Tianjin, and Hebei are sub-healt hy, normal, and sub-morbid; the storage capacity of rivers and lakes and thew ater consumption of 10,000 yuan of indust rial added value are the main indicators that affet the healthy water cycle in the Beijing-Tianjin-Hebei region.However, the development of the various indicators is not balanced, and there is still much room for improvement.
Based on clarifying the connotation of the healthy water cycle, five criterion layers covering water resources,water environment, water ecology, the water utility, and water disasters were constructed, including precipitation, per capita water resources, per mu water resources, and groundwater supply ratio. The water cycle health evaluation index system of other 18 indicators, using the combination of analytic hierarchy process and entropy met hod to assign weights and using fuzzy comprehensive evaluation method to evaluate the water cycle health status of the Beijing-Tianjin- Hebei region from 2009 to 2018.The evaluration results show that: the overall water cycle health in the Beijing-Tianjirn-Hebei region has gradually improved in the past ten years. The water cycle health levels in Beijing, Tianjin, and Hebei are sub-healt hy, normal, and sub-morbid; the storage capacity of rivers and lakes and thew ater consumption of 10,000 yuan of indust rial added value are the main indicators that affet the healthy water cycle in the Beijing-Tianjin-Hebei region.However, the development of the various indicators is not balanced, and there is still much room for improvement.
2021, 19(1):75-82.
Abstract:
The change in water resources and the consequent water resources supply pressure in Uzbekist an is analyzed by literrture reviewing, based on agricultural, remote sensing, and hydro-meteorological reanalysis data. The analysis shows that: since1980, the average annual water withdraw als have increased from 5.9 billion m3 to 10.2 bilion m3 in Uzbekistan and more than 90% of water resources are consumed for irrigation agriculture: despite declines in both areas of cropland(200 km2/a) and the proportion of high water-consuming crops(-3.24%), the water demand per unit area is still increasing(3.27 mm/a) under the influence of a warming climate(0.31℃/10a), the overall water demand is still increasing (275 million m3/a); simultaneously, the decrease of upstream inflow and the further increase in water use in upstream countris will further aggravate the regional water short age and supply pressure. To deal with the problem of water resouroes, Uzbekistan needs to strengthen water management, improve irrigation technology, and improve water use efficiency. Therefore, it is necessary to strengthen cooperation with neighboring countries and to seek ways to improve the allocation and management of water resources of transboundary rivers. The study will help to enhance understanding of the water resource problems in U zbekistan and provide a scientific basis for addressing them, as well as support the development of cooperation in the "Belt and Road"region.
The change in water resources and the consequent water resources supply pressure in Uzbekist an is analyzed by literrture reviewing, based on agricultural, remote sensing, and hydro-meteorological reanalysis data. The analysis shows that: since1980, the average annual water withdraw als have increased from 5.9 billion m3 to 10.2 bilion m3 in Uzbekistan and more than 90% of water resources are consumed for irrigation agriculture: despite declines in both areas of cropland(200 km2/a) and the proportion of high water-consuming crops(-3.24%), the water demand per unit area is still increasing(3.27 mm/a) under the influence of a warming climate(0.31℃/10a), the overall water demand is still increasing (275 million m3/a); simultaneously, the decrease of upstream inflow and the further increase in water use in upstream countris will further aggravate the regional water short age and supply pressure. To deal with the problem of water resouroes, Uzbekistan needs to strengthen water management, improve irrigation technology, and improve water use efficiency. Therefore, it is necessary to strengthen cooperation with neighboring countries and to seek ways to improve the allocation and management of water resources of transboundary rivers. The study will help to enhance understanding of the water resource problems in U zbekistan and provide a scientific basis for addressing them, as well as support the development of cooperation in the "Belt and Road"region.
2021, 19(1):83-91,128.
Abstract:
The groundwater recession curve in the Shaying River basin is fitted and compared by linear and nonlinear relatio ships. Based on the improved SWAT(soil and w ater assessment tool) model, the runoff process of the Shaying River basin was simulated, and the simulation effect was evaluated by the Nash Sutcliffe efficiency coefficient, percentage deviation, and determination coefficient. On this basis, the annual and interannual variation characteristics of the runoff process w ere analyzed. The results show that: the non-linear fitting of the groundwater recession curve in the Shaying River basin was better than the linear fitting, and the simulation results of the model based on the non-linear process were good; the surface runoff, the interflow, and the baseflow accounted for 55.5%,25.4%, and 19.1% of the runoff, respectively, the runoff in winter was mainly supplied by the baseflow, the annual distribution of runoff was consistent with the change of precipitation,with obvious seasonal change and nonuniformity; the fluctuation of surface runoff and baseflow is consistent with the change of runoff, showing an upward trend, while the interflow shows a do wnward t rend from 1961 to 2014.
The groundwater recession curve in the Shaying River basin is fitted and compared by linear and nonlinear relatio ships. Based on the improved SWAT(soil and w ater assessment tool) model, the runoff process of the Shaying River basin was simulated, and the simulation effect was evaluated by the Nash Sutcliffe efficiency coefficient, percentage deviation, and determination coefficient. On this basis, the annual and interannual variation characteristics of the runoff process w ere analyzed. The results show that: the non-linear fitting of the groundwater recession curve in the Shaying River basin was better than the linear fitting, and the simulation results of the model based on the non-linear process were good; the surface runoff, the interflow, and the baseflow accounted for 55.5%,25.4%, and 19.1% of the runoff, respectively, the runoff in winter was mainly supplied by the baseflow, the annual distribution of runoff was consistent with the change of precipitation,with obvious seasonal change and nonuniformity; the fluctuation of surface runoff and baseflow is consistent with the change of runoff, showing an upward trend, while the interflow shows a do wnward t rend from 1961 to 2014.
2021, 19(1):92-102.
Abstract:
Multi-regional LMDI decomposition model and Information entropy were adopted to analyze spatiotemporal variations of the productive water consumption structure in 21 cities in 4 regions of Guangdong Province from 2005 to 2018, and decompose the five driving factors, including population size, population distribution, economic development, industrial structure, and water consumption intensity. The results show ed that: the overall productive water consumption in Guangdong showed a downward trend from 2005 to 2018, and the reduction was more remarkable in the urban agglomeration of Pearl River Delt (PRD), overall, the productive water consumption efficiency of all industries improved with a significant difference among different regions;the proportion of the productive water consumption of three industries was found stable, and the water use structure in the PRD region was relatively balanced, and the water use structure in the east,west, and north of Guangdong tend to be unitary, with water used for the primary industry; economic development was the dominant positive driver leading to the increase of productive water consumption, water consumption intensity was found to be the main negative driving factor, while the industrial structure was the seondary negative factor, respect ively.The promotion effect of population size driver was not significant.Population distribution driver showed a slight promotion effect in PRD, while a slight inhibitory effect in the northern, eastern, and western Guangdong.The results of this research have a certain reference value for coordinating the relationship between re gional industrial development and w ater resources and formulating a reasonable w ater resource strategy and planning.
Multi-regional LMDI decomposition model and Information entropy were adopted to analyze spatiotemporal variations of the productive water consumption structure in 21 cities in 4 regions of Guangdong Province from 2005 to 2018, and decompose the five driving factors, including population size, population distribution, economic development, industrial structure, and water consumption intensity. The results show ed that: the overall productive water consumption in Guangdong showed a downward trend from 2005 to 2018, and the reduction was more remarkable in the urban agglomeration of Pearl River Delt (PRD), overall, the productive water consumption efficiency of all industries improved with a significant difference among different regions;the proportion of the productive water consumption of three industries was found stable, and the water use structure in the PRD region was relatively balanced, and the water use structure in the east,west, and north of Guangdong tend to be unitary, with water used for the primary industry; economic development was the dominant positive driver leading to the increase of productive water consumption, water consumption intensity was found to be the main negative driving factor, while the industrial structure was the seondary negative factor, respect ively.The promotion effect of population size driver was not significant.Population distribution driver showed a slight promotion effect in PRD, while a slight inhibitory effect in the northern, eastern, and western Guangdong.The results of this research have a certain reference value for coordinating the relationship between re gional industrial development and w ater resources and formulating a reasonable w ater resource strategy and planning.
10 Quantitative analysis of runoff evolution and driving factors in the upper reaches of Datong River
2021, 19(1):103-110,167.
Abstract:
In the past 60 years, temperature, precipitation, and potential evapotranspirat ion in the upper reaches of Datong River, which is located in the Qilian Mountain area, the northw est edge of Qinghai-Tibetan Plateau, have increased significantly, with the synthetic effect of 50% glacial ablation, permafrost degradation, and 797 km2 marsh degradation in the source area, annual runoff depth increased with a trend of 6.0 mm/(10 a); the base flow segmentation indicates that the total baseflow and its prportion have both increased since the runoff abrupt change,The base flow in August changed from the valley value between July and September to the peak;a quantitative analysis of the driving factors of the increase in runoff is carried out by the climate elasticity method based on the Budyko assumption. Compared with the base period,the annual runoff depth changes by +33.6mm after the sudden change of runoff, and the increase in precipitation affects +18.3mm. The effect of evapotranspiration change is-3.0 mm, the effect of glacier melting on runoff increment is at most +10.0 mm, and the remaining term +8.3mm is the combined effect of frozen soil degradation and error terms. Due to the different influence mechanism and duration of each element, the future hy drological situation is still unclear.
In the past 60 years, temperature, precipitation, and potential evapotranspirat ion in the upper reaches of Datong River, which is located in the Qilian Mountain area, the northw est edge of Qinghai-Tibetan Plateau, have increased significantly, with the synthetic effect of 50% glacial ablation, permafrost degradation, and 797 km2 marsh degradation in the source area, annual runoff depth increased with a trend of 6.0 mm/(10 a); the base flow segmentation indicates that the total baseflow and its prportion have both increased since the runoff abrupt change,The base flow in August changed from the valley value between July and September to the peak;a quantitative analysis of the driving factors of the increase in runoff is carried out by the climate elasticity method based on the Budyko assumption. Compared with the base period,the annual runoff depth changes by +33.6mm after the sudden change of runoff, and the increase in precipitation affects +18.3mm. The effect of evapotranspiration change is-3.0 mm, the effect of glacier melting on runoff increment is at most +10.0 mm, and the remaining term +8.3mm is the combined effect of frozen soil degradation and error terms. Due to the different influence mechanism and duration of each element, the future hy drological situation is still unclear.
2021, 19(1):111-118.
Abstract:
Doumen reservo ir is an important part of the water diversion and distribution project from the Hanjiang River to the Weihe river in Shaanxi province. The impact of Doumen reservoir's impoundment on regional groundwater dynamics was studied to provide a relevant scientific basis for the later construction of the reservoir and regional water resources management.Through the establishment of the Meteorologicat-Groundwater Monitoring System of the Doumen reservoir experimental section, the dynamic characteristics of the groundwater level were analyzed by the Manr-Kendall test in the study area. The time variation characteristics of the groundw ater level were analyzed by the coefficient of variation method, and the grey correlation md hod was used to reveal its dominant influence factors. The results show that: the overall performance of the groundw ater level in the experimental section of Doumen reservoir is an upward trend and obvious characterist ics of high and dry conditions, with an increase of about 0.5-2.0 m/a; the leakage of the test section was negatively correlated with the change of groundwater level, and the leakage had an effected on groundwater level, there was a certain spatial difference in the impat, that was, the impacd on the water table in the east was greater than that in the west; the dominant influencing factor on the groundwater level was rainfall in the west, and leakage and rainfall were in the east.
Doumen reservo ir is an important part of the water diversion and distribution project from the Hanjiang River to the Weihe river in Shaanxi province. The impact of Doumen reservoir's impoundment on regional groundwater dynamics was studied to provide a relevant scientific basis for the later construction of the reservoir and regional water resources management.Through the establishment of the Meteorologicat-Groundwater Monitoring System of the Doumen reservoir experimental section, the dynamic characteristics of the groundwater level were analyzed by the Manr-Kendall test in the study area. The time variation characteristics of the groundw ater level were analyzed by the coefficient of variation method, and the grey correlation md hod was used to reveal its dominant influence factors. The results show that: the overall performance of the groundw ater level in the experimental section of Doumen reservoir is an upward trend and obvious characterist ics of high and dry conditions, with an increase of about 0.5-2.0 m/a; the leakage of the test section was negatively correlated with the change of groundwater level, and the leakage had an effected on groundwater level, there was a certain spatial difference in the impat, that was, the impacd on the water table in the east was greater than that in the west; the dominant influencing factor on the groundwater level was rainfall in the west, and leakage and rainfall were in the east.
2021, 19(1):119-128.
Abstract:
Standard Precipitation Evapotranspiration Index (SPEI) is one of the most w idely used meteorological drought indexes globally for drought monitoring. Determining the appropriate SPEI time scale is the premise of using SPEI for monitoring agri cultural drought. Taken the latest national soil moisture reanalysis products as a rference,the most suitable SPEI time scale for haracderizing agricult ural drought in Hunan Province is det ermined based on maximum correlation analysis and then the spatial and tem poral evolution characteristics of agriultural drought in H unan Province from 1960 to 2014 is analyzed.The results showed that: the most suitable timescale of SPEI to characterize agricultural drought is SPEI6 in the whole province; the agricultural drought characterized by SPEF-6 showed an insignificant decrease trend from 1960 to 2014 in the whole province,the frequency of moderate and severe droughts was 14. 4% on average, and the frequency of severe and extreme droughts was 4.9% on average; in terms of seasonal distribution, moderate and severe droughts have the highest frequency in winter, followed by autumn; severe and extreme droughts also have the highest frequency in winter, followed by spring; regarding interdecadal variations, the frequency of agricultural drought in the whole province was highest in the1960s and then continued to decrease, reaching the lowest value in the 1990s and rapidly increasing in the 2000s.
Standard Precipitation Evapotranspiration Index (SPEI) is one of the most w idely used meteorological drought indexes globally for drought monitoring. Determining the appropriate SPEI time scale is the premise of using SPEI for monitoring agri cultural drought. Taken the latest national soil moisture reanalysis products as a rference,the most suitable SPEI time scale for haracderizing agricult ural drought in Hunan Province is det ermined based on maximum correlation analysis and then the spatial and tem poral evolution characteristics of agriultural drought in H unan Province from 1960 to 2014 is analyzed.The results showed that: the most suitable timescale of SPEI to characterize agricultural drought is SPEI6 in the whole province; the agricultural drought characterized by SPEF-6 showed an insignificant decrease trend from 1960 to 2014 in the whole province,the frequency of moderate and severe droughts was 14. 4% on average, and the frequency of severe and extreme droughts was 4.9% on average; in terms of seasonal distribution, moderate and severe droughts have the highest frequency in winter, followed by autumn; severe and extreme droughts also have the highest frequency in winter, followed by spring; regarding interdecadal variations, the frequency of agricultural drought in the whole province was highest in the1960s and then continued to decrease, reaching the lowest value in the 1990s and rapidly increasing in the 2000s.
13 Characteristics and driving forces of land use change in the Yellow River basin from 1980 to 2015
2021, 19(1):129-139.
Abstract:
The changes in land use types, and the change rate of land use based on the land use data of six periods from 1980 to 2015in the Yellow River basin using a dynamic at titude index were analyzed.The transfer matrix was used to analyze the types and quant ities of land use transfer based on administrative partitions and the provinces within the basin during 1980-2000 and 2001-2015, and the main driving factors inf luencing land use were explored. The results showed tht: land use in the Yellow Rier basin has significant characteristics in terms of quantity and structure, grassland, dryland, and w oodland were the main land use types in the Yellow River basin, from 1980 to 2015, the area of dryland, grassland, water area, and unused land decreased by 1.60%,1.23%,6.66%, and 1.84%, respectively, the areas of paddy fields, woodland, and urban and rural land increased by 8.22%,2.53%, and 44.32% respectively; in terms of single land use type, the change rate of urban and rural land was the fastest, and the rest was relatively small; the land use transformation in the Yellow River basin was m ainly concent rated inthe middle and east, and the transformation was obvious in the middle and lower reaches of the provinces; climate change, population growth, and human economic development were the main driving factors of land use change in the Yellow River basin.
The changes in land use types, and the change rate of land use based on the land use data of six periods from 1980 to 2015in the Yellow River basin using a dynamic at titude index were analyzed.The transfer matrix was used to analyze the types and quant ities of land use transfer based on administrative partitions and the provinces within the basin during 1980-2000 and 2001-2015, and the main driving factors inf luencing land use were explored. The results showed tht: land use in the Yellow Rier basin has significant characteristics in terms of quantity and structure, grassland, dryland, and w oodland were the main land use types in the Yellow River basin, from 1980 to 2015, the area of dryland, grassland, water area, and unused land decreased by 1.60%,1.23%,6.66%, and 1.84%, respectively, the areas of paddy fields, woodland, and urban and rural land increased by 8.22%,2.53%, and 44.32% respectively; in terms of single land use type, the change rate of urban and rural land was the fastest, and the rest was relatively small; the land use transformation in the Yellow River basin was m ainly concent rated inthe middle and east, and the transformation was obvious in the middle and lower reaches of the provinces; climate change, population growth, and human economic development were the main driving factors of land use change in the Yellow River basin.
2021, 19(1):140-150.
Abstract:
A series of hydrogeological survey and environment geology survey on Hetao basin has been carried out for many years. Two hundred and ninety eight groundwater samples from the shallow aquifer and three hundred and eighty-two hydrogeological borehole loggings were collected, and it was founded that 95% of samples had high arsenic groundwater(As>10g/L) in the Hetao basin and were distributed in the paleochannel zone and flood fans of Yellow River. The high arsenic groundwater distribution was discovered in the southern Hetao basin, and the four flood fans formed by bursting, diversion of ancient Y ellow River course since the Late Pleistocene has an corresponding relationship with spatial variability of high arsenic groundwater.The paleochannel zone and flood fans of Yellow River represent hy drogeochemical characteristics of the strong reducing environment, serious evaporation, and the low infiltration recharge of surface water. Due to the influence of pH value and reductive dissolution of iron oxides, the arsenic concentration in flood fans was lower than those in the paleochannel zone of the Yellow River. Results show that: the sedimentary environment controlled the hydrogeochemical processes of the shallow aquifer and played a decisive role in the distribution of high-arsenic groundwater.
A series of hydrogeological survey and environment geology survey on Hetao basin has been carried out for many years. Two hundred and ninety eight groundwater samples from the shallow aquifer and three hundred and eighty-two hydrogeological borehole loggings were collected, and it was founded that 95% of samples had high arsenic groundwater(As>10g/L) in the Hetao basin and were distributed in the paleochannel zone and flood fans of Yellow River. The high arsenic groundwater distribution was discovered in the southern Hetao basin, and the four flood fans formed by bursting, diversion of ancient Y ellow River course since the Late Pleistocene has an corresponding relationship with spatial variability of high arsenic groundwater.The paleochannel zone and flood fans of Yellow River represent hy drogeochemical characteristics of the strong reducing environment, serious evaporation, and the low infiltration recharge of surface water. Due to the influence of pH value and reductive dissolution of iron oxides, the arsenic concentration in flood fans was lower than those in the paleochannel zone of the Yellow River. Results show that: the sedimentary environment controlled the hydrogeochemical processes of the shallow aquifer and played a decisive role in the distribution of high-arsenic groundwater.
2021, 19(1):151-157,197.
Abstract:
The temporal and spatial evolution law of the wandering river regime in the lower Yellow River was analyzed to provide t heoretical support and practical value for further understanding the evolution characteristics of the lower Yellow River channel. Based on the systematic collection of river regime observation data of typical sections of the wandering channel in the lower Yellow River from 1960 to 2015, with the Mann-Kendall trend test and Fisher break point test method, the average river width and the migration rate of the mainline of the wandering channel in the lower Yellow River from 1960 to 2015 were analyzed. The results show that: in the past 60 years, the wandering channel in the lower Yellow River showed a clear manifestrion, that was, they were distributed in the shape of a lotus on the plane,while the temporal and spatial distribution of the mainline adjustment rate was not significant; the cross section of the lower Yellow River was the key node of the plane lotus-shaped distribution, and the whole river channd was divided into three sections (the first reach,Tiexie-Yudian section, with the average river width of 1627m; the second reach,Yudian-Chanfang section,with the average river width of 1477m; the third reach, Char fang-Gaocun section, with the average river widt h of 1074m, respectively).
The temporal and spatial evolution law of the wandering river regime in the lower Yellow River was analyzed to provide t heoretical support and practical value for further understanding the evolution characteristics of the lower Yellow River channel. Based on the systematic collection of river regime observation data of typical sections of the wandering channel in the lower Yellow River from 1960 to 2015, with the Mann-Kendall trend test and Fisher break point test method, the average river width and the migration rate of the mainline of the wandering channel in the lower Yellow River from 1960 to 2015 were analyzed. The results show that: in the past 60 years, the wandering channel in the lower Yellow River showed a clear manifestrion, that was, they were distributed in the shape of a lotus on the plane,while the temporal and spatial distribution of the mainline adjustment rate was not significant; the cross section of the lower Yellow River was the key node of the plane lotus-shaped distribution, and the whole river channd was divided into three sections (the first reach,Tiexie-Yudian section, with the average river width of 1627m; the second reach,Yudian-Chanfang section,with the average river width of 1477m; the third reach, Char fang-Gaocun section, with the average river widt h of 1074m, respectively).
2021, 19(1):158-167.
Abstract:
To understand the geochemical characteristics of rare earth elements (REE) in groundwater of Lalin River basin, the rare earth elements in the regional groundwater system were studied through rare earth element mass concentration testing and North American Shale Composite(NASC) normalized analysis. The distribution characteristics of REE speciation along the groundwater flow path were studied using PHREEQC software modeling. The results showed that: the total amount of rareearth elements(∑REE) in the groundwater of the Lalin River basin ranged from 0.030 to 2.649μg/L(mean value 0.328μg/L); Light Rare Earth Elements(LREE) is quite depleted, while Heavy Rare Earth Elements (HREE) are relatively enriched, with significant positive Eu anomalies and mild Ce negative anomalies; the REE in the groundwater mainly existed in the form of Ln CO3+and Ln(CO3)2-; along the regional groundwater flow path, the groundwater in Lalin River basin demonstratel the decline of REE concentration and the increase of positive Eu anomalies. Furthermore, LnCO3+ concentrations decreased and Ln(CO3)2- increased respectively along the groundwater flow path; the formation of dicarbonate complexes of rare earth elements was the main reason for the relative enrichment of HREE.
To understand the geochemical characteristics of rare earth elements (REE) in groundwater of Lalin River basin, the rare earth elements in the regional groundwater system were studied through rare earth element mass concentration testing and North American Shale Composite(NASC) normalized analysis. The distribution characteristics of REE speciation along the groundwater flow path were studied using PHREEQC software modeling. The results showed that: the total amount of rareearth elements(∑REE) in the groundwater of the Lalin River basin ranged from 0.030 to 2.649μg/L(mean value 0.328μg/L); Light Rare Earth Elements(LREE) is quite depleted, while Heavy Rare Earth Elements (HREE) are relatively enriched, with significant positive Eu anomalies and mild Ce negative anomalies; the REE in the groundwater mainly existed in the form of Ln CO3+and Ln(CO3)2-; along the regional groundwater flow path, the groundwater in Lalin River basin demonstratel the decline of REE concentration and the increase of positive Eu anomalies. Furthermore, LnCO3+ concentrations decreased and Ln(CO3)2- increased respectively along the groundwater flow path; the formation of dicarbonate complexes of rare earth elements was the main reason for the relative enrichment of HREE.
2021, 19(1):168-178.
Abstract:
To understand the research status and key points in the field of groundwater pollution at home and abroad,8117 high quality pieces of literature in the field of groundwater pollution were collected from academic journals from 2009 to 2019, and the scientific knowledge map was drawn by the visualization soft ware CiteSpaceV.5.6.R3. Through the statistics, clustering, and visualization of the paper volume, research content, research institutions, and authors of groundwater research, the overall situation of groundwater pollution research is explored in multiple dimensions.The results show that: the total amount of scierrtific research papers in the field of groundwater pollution research is increasing, the research fouses on three aspects: pollutant characteristics, pollution evaluation, and pollution remediation, nitrate and arsenic pollution has become the research focus of groundwater pollution; the Institute of Hydrogeology and Environmental Geology of the Chinese A cademy of Geological Sciences and Jilin University have made im portant contributions to the development of domestic groundwater polution, and the research team has developed decentralized and diversified over time China University of Geosciences, Chinese Academy of Sciences, and USGS are the most inf luential institutions in the world. Wang Yanxin's team of academicians from China University of Geosciences(Wuhan) has great international influence in the field of groundwater pollution research. Under the demand of ecological civilization construction in China, the transformation of groundwater pollution remediation from theoretical research to the application of contaminated sites is still the current research trend.
To understand the research status and key points in the field of groundwater pollution at home and abroad,8117 high quality pieces of literature in the field of groundwater pollution were collected from academic journals from 2009 to 2019, and the scientific knowledge map was drawn by the visualization soft ware CiteSpaceV.5.6.R3. Through the statistics, clustering, and visualization of the paper volume, research content, research institutions, and authors of groundwater research, the overall situation of groundwater pollution research is explored in multiple dimensions.The results show that: the total amount of scierrtific research papers in the field of groundwater pollution research is increasing, the research fouses on three aspects: pollutant characteristics, pollution evaluation, and pollution remediation, nitrate and arsenic pollution has become the research focus of groundwater pollution; the Institute of Hydrogeology and Environmental Geology of the Chinese A cademy of Geological Sciences and Jilin University have made im portant contributions to the development of domestic groundwater polution, and the research team has developed decentralized and diversified over time China University of Geosciences, Chinese Academy of Sciences, and USGS are the most inf luential institutions in the world. Wang Yanxin's team of academicians from China University of Geosciences(Wuhan) has great international influence in the field of groundwater pollution research. Under the demand of ecological civilization construction in China, the transformation of groundwater pollution remediation from theoretical research to the application of contaminated sites is still the current research trend.
2021, 19(1):179-190.
Abstract:
To study the interaction of polycyclic aromatic hydrocarbons(PAHs) in river water and different groundwater aquifer, the water qua lity data of river water and groundwater in different seasons in upstream and dow nstream of Wenyu River in the North Canal basin were collected. The contrast analysis and significance analysis methods were used to study the omposition, content, and spatial and temporal distribution characteristics of PAHs in river water and groundwater. Besides, the risk entropy method was used for risk assessmnt. The results showed that: the detection rate of PAHs in all 16 kinds of PAHs was 100%, except for BAP and Daha, while the other 14 PAHs were detected in river water, phreatic water, and confined water; the composition of PAHs was mainly Nap(1 587.42 ng/L), accounting for 85.6% of the total mass concentration; the total mass concentration of PAHs in spring was significantly lower than that in summer in phreatic water and confined water, the mass concentration of 2~3- ring PAHs was higher than that of 4-ring PAHs;t he mass concentration of PAHs in the phreatic water of the North Canal was higher than that in the confined water of the Wenyu river. Nap, Flu, and Phe were the main polutants in the groundwater of Wenyu river. Nap, Acy, and Phe were the main pollutants in the groundwater of the North Canal; the total mass concentration of PAHs in the upper reaches of the river water was lower than that in the lower reaches, and the main pollutants were Nap and Phe; Nap, Flu, Phe, Ant, Fla, Pyr, and BaA, respectively, had significant differences in different situations, except for BaA, BbF, BaP, and Dib,while the other PA Hs had significant differences in different seasonal corrditions; according to the risk entropy method, the ecological risk in summer was relatively low compared to different seasons and situations.
To study the interaction of polycyclic aromatic hydrocarbons(PAHs) in river water and different groundwater aquifer, the water qua lity data of river water and groundwater in different seasons in upstream and dow nstream of Wenyu River in the North Canal basin were collected. The contrast analysis and significance analysis methods were used to study the omposition, content, and spatial and temporal distribution characteristics of PAHs in river water and groundwater. Besides, the risk entropy method was used for risk assessmnt. The results showed that: the detection rate of PAHs in all 16 kinds of PAHs was 100%, except for BAP and Daha, while the other 14 PAHs were detected in river water, phreatic water, and confined water; the composition of PAHs was mainly Nap(1 587.42 ng/L), accounting for 85.6% of the total mass concentration; the total mass concentration of PAHs in spring was significantly lower than that in summer in phreatic water and confined water, the mass concentration of 2~3- ring PAHs was higher than that of 4-ring PAHs;t he mass concentration of PAHs in the phreatic water of the North Canal was higher than that in the confined water of the Wenyu river. Nap, Flu, and Phe were the main polutants in the groundwater of Wenyu river. Nap, Acy, and Phe were the main pollutants in the groundwater of the North Canal; the total mass concentration of PAHs in the upper reaches of the river water was lower than that in the lower reaches, and the main pollutants were Nap and Phe; Nap, Flu, Phe, Ant, Fla, Pyr, and BaA, respectively, had significant differences in different situations, except for BaA, BbF, BaP, and Dib,while the other PA Hs had significant differences in different seasonal corrditions; according to the risk entropy method, the ecological risk in summer was relatively low compared to different seasons and situations.
2021, 19(1):191-197.
Abstract:
Standardized construction cost estimation models based on the regression analysis method were established, including the unit structure cost model and the water plant equipment purchase cost model, and combined with the water plant water ir take head, other types of buildings and general floor layout cost analysis and engineering construction and other expenses and reserve costs were estimated for the cost of the water plant.Acoording to the actual project, the obtained model was verified.The estimated errors of the const ruction cost of the unit structure were all controlled within 30%,which meet the accuracy of control requirements of the project proposal stage, the actual equipment purchase cost was-11.30% of the estimated error, the overallost stimation error rate of the water plant cost was only 4.03%. The cost model of the water plant based on regression analysis can be applied to estimate the cost of a water plant rapidly and ensure good estimation accuracy.
Standardized construction cost estimation models based on the regression analysis method were established, including the unit structure cost model and the water plant equipment purchase cost model, and combined with the water plant water ir take head, other types of buildings and general floor layout cost analysis and engineering construction and other expenses and reserve costs were estimated for the cost of the water plant.Acoording to the actual project, the obtained model was verified.The estimated errors of the const ruction cost of the unit structure were all controlled within 30%,which meet the accuracy of control requirements of the project proposal stage, the actual equipment purchase cost was-11.30% of the estimated error, the overallost stimation error rate of the water plant cost was only 4.03%. The cost model of the water plant based on regression analysis can be applied to estimate the cost of a water plant rapidly and ensure good estimation accuracy.
2021, 19(1):198-206.
Abstract:
The Menglour Qifang inverted siphon is 72 km long in the north Hubei water diversion project.. The setting of the out let boundary under the control of its gate has a significant impact on the hydraulic response process in the pipe. The super-long inverted siphon out let gate is located at the junct ion of the pressure section and the open channel set ion. It belongs to the orifice submerged outflow of the long pressure pipeline and has the characteristics of high coupling and nonlinearity. The commonly used pressure tunnel discharge formula does not consider the unsteady flow in the inverted siphon and is not suitable as the out let boundary of the long inverted siphon.The Henry formula can reasonably reflect the hydraulic response law under the gate control, but it is difficult to reflect the vibration characteristics of water hammer. On this basis,a boundary treatment method for ulverting the exit gate was proposed, the simulation results revealed that there was significant water hammer during rapid closing in the inverted siphon, the maximum water hammer pressure in the downstream accident conditions was 25.1m(the initialpressure was 8.8m), the maximum water hammer amplitude is 16 m, and the average pressure variation characteristics are consistent with similar experimental results.The proposed method can provide technical support for the int ervention schedule in the water transfer project in northern Hubei and is also a reference for similarly dynamic boundary simulation modeling in the free surf ace pressurized flow.
The Menglour Qifang inverted siphon is 72 km long in the north Hubei water diversion project.. The setting of the out let boundary under the control of its gate has a significant impact on the hydraulic response process in the pipe. The super-long inverted siphon out let gate is located at the junct ion of the pressure section and the open channel set ion. It belongs to the orifice submerged outflow of the long pressure pipeline and has the characteristics of high coupling and nonlinearity. The commonly used pressure tunnel discharge formula does not consider the unsteady flow in the inverted siphon and is not suitable as the out let boundary of the long inverted siphon.The Henry formula can reasonably reflect the hydraulic response law under the gate control, but it is difficult to reflect the vibration characteristics of water hammer. On this basis,a boundary treatment method for ulverting the exit gate was proposed, the simulation results revealed that there was significant water hammer during rapid closing in the inverted siphon, the maximum water hammer pressure in the downstream accident conditions was 25.1m(the initialpressure was 8.8m), the maximum water hammer amplitude is 16 m, and the average pressure variation characteristics are consistent with similar experimental results.The proposed method can provide technical support for the int ervention schedule in the water transfer project in northern Hubei and is also a reference for similarly dynamic boundary simulation modeling in the free surf ace pressurized flow.
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