Volume 17,Issue 2,2019 Table of Contents
2019, 17(2):1-9.
Abstract:
Water resources are of vital importance to social and economic development.The relationship between industrial structure and water consumed structure,revealing the link between economic development and water resources utilization and allocating water resources rationally,is of great significance to the Beijing Tianjin Hebei region from strategic point of view.In this paper,we used the industrial structure and water consumed structure data from Beijing,Tianjin and Hebei Province during 2002 to 2016,and the indicators,such as,the coordination degree of industrial structure and water consumed structure,to investigate the evolution trends of industrial structure and water consumed structure in Beijing Tianjin Hebei region.The linear regression method based on the component data was also used to establish a linear regression model between industrial structure and water consumption structure.The results showed that the proportion of the added value of the tertiary industry in Beijing was highly related to the proportion of water consumption of the tertiary industry.The proportion of the added value of the secondary industry in Hebei Province and the proportion of water consumed in the secondary industry also showed a strong correlation.
Water resources are of vital importance to social and economic development.The relationship between industrial structure and water consumed structure,revealing the link between economic development and water resources utilization and allocating water resources rationally,is of great significance to the Beijing Tianjin Hebei region from strategic point of view.In this paper,we used the industrial structure and water consumed structure data from Beijing,Tianjin and Hebei Province during 2002 to 2016,and the indicators,such as,the coordination degree of industrial structure and water consumed structure,to investigate the evolution trends of industrial structure and water consumed structure in Beijing Tianjin Hebei region.The linear regression method based on the component data was also used to establish a linear regression model between industrial structure and water consumption structure.The results showed that the proportion of the added value of the tertiary industry in Beijing was highly related to the proportion of water consumption of the tertiary industry.The proportion of the added value of the secondary industry in Hebei Province and the proportion of water consumed in the secondary industry also showed a strong correlation.
2019, 17(2):10-19.
Abstract:
Trends of drought and flood are very important for the planning and construction of Xiong′an New Area.In this paper,550 years of historical drought and flood grade data from 1469 to 2018 in Xiong′an New Area were constructed.The data series of drought and flood grade with frequency of drought prone and flood prone years in every 10 years were our research object,which were abbreviated as drought prone and flood prone sequences in our study.The turning points of the sequences were identified by Lee Heghinian method,ordered clustering and moving test.The trends of the sequences were identified with linear trend regression test and Spearman rank method.The sequences were predicted with a R/S analysis method.The results showed that there was a turning point in 1579-1588 for the flood prone sequence.The subsequence showed an insignificant upward trend before this turning point,and a significant upward trend after it.There was a turning point in 1919 to 1928 for the drought prone sequence.The subsequence showed an insignificant downward trend before this turning point,and an insignificant upward trend after it.At the significant level of 0.05,Hurst index forecasting showed that the flood prone sequence would show a trend varying from significantly decreasing to insignificantly increasing in the future,while the drought prone sequence would show a trend varying from insignificantly increasing to significantly decreasing.
Trends of drought and flood are very important for the planning and construction of Xiong′an New Area.In this paper,550 years of historical drought and flood grade data from 1469 to 2018 in Xiong′an New Area were constructed.The data series of drought and flood grade with frequency of drought prone and flood prone years in every 10 years were our research object,which were abbreviated as drought prone and flood prone sequences in our study.The turning points of the sequences were identified by Lee Heghinian method,ordered clustering and moving test.The trends of the sequences were identified with linear trend regression test and Spearman rank method.The sequences were predicted with a R/S analysis method.The results showed that there was a turning point in 1579-1588 for the flood prone sequence.The subsequence showed an insignificant upward trend before this turning point,and a significant upward trend after it.There was a turning point in 1919 to 1928 for the drought prone sequence.The subsequence showed an insignificant downward trend before this turning point,and an insignificant upward trend after it.At the significant level of 0.05,Hurst index forecasting showed that the flood prone sequence would show a trend varying from significantly decreasing to insignificantly increasing in the future,while the drought prone sequence would show a trend varying from insignificantly increasing to significantly decreasing.
2019, 17(2):20-28.
Abstract:
The characteristics of virtual water consumption have great impacts on water resources demand,therefore,it is of significance to investigate virtual water consumption and its differences of resident diet to build a healthy consumption model.This paper analyzed the residents′ dietary virtual water consumption in Beijing Tianjin Hebei region from 2000 to 2015,and explored their influencing factors.Results showed that a) The average annual dietary virtual water consumption during 2000-2015 was 9 833 billion m3,5.744 billion m3 and 24 002 billion m3 in Beijing,Tianjin and Hebei,respectively.The virtual water consumption also showed an obvious increasing trend,which could bring critical pressure to the regional water resources security;b)The residents′dietary virtual water consumption per capita was higher in Beijing than those of Tianjin and Hebei,and was higher in urban than that of rural areas;c) The consumption diversity index of residents′ dietary virtual water consumption also showed an upward trend,and it was higher in urban than that of rural areas as well.However,the gap was becoming narrowing gradually with time;d)The difference from consumption of high virtual water,such as meat and edible oil,was the main reasons for virtual water consumption.The improvement of grain productivity plays an important role in reducing the virtual water consumption per capita.The regulations of virtual water remand can be used to improve the efficiency of water consumption,construct a more reasonable consumption structure,and guide healthy consumption habits.
The characteristics of virtual water consumption have great impacts on water resources demand,therefore,it is of significance to investigate virtual water consumption and its differences of resident diet to build a healthy consumption model.This paper analyzed the residents′ dietary virtual water consumption in Beijing Tianjin Hebei region from 2000 to 2015,and explored their influencing factors.Results showed that a) The average annual dietary virtual water consumption during 2000-2015 was 9 833 billion m3,5.744 billion m3 and 24 002 billion m3 in Beijing,Tianjin and Hebei,respectively.The virtual water consumption also showed an obvious increasing trend,which could bring critical pressure to the regional water resources security;b)The residents′dietary virtual water consumption per capita was higher in Beijing than those of Tianjin and Hebei,and was higher in urban than that of rural areas;c) The consumption diversity index of residents′ dietary virtual water consumption also showed an upward trend,and it was higher in urban than that of rural areas as well.However,the gap was becoming narrowing gradually with time;d)The difference from consumption of high virtual water,such as meat and edible oil,was the main reasons for virtual water consumption.The improvement of grain productivity plays an important role in reducing the virtual water consumption per capita.The regulations of virtual water remand can be used to improve the efficiency of water consumption,construct a more reasonable consumption structure,and guide healthy consumption habits.
2019, 17(2):29-39.
Abstract:
Beijing Tianjin Hebei region,located in the "capital circle" of China,has an extremely important strategic position.The shortage of water resources has become one of the factors that seriously restrict its economic and social developments.Based on the data of water resources utilization and urban economic development from 2000 to 2016,this study firstly investigated the spatiotemporal variations of quantity,structure and efficiency of water resources in Beijing Tianjin Hebei region with coefficient of variation and the Theil coefficient.Secondly,the grey correlation method was used to explore the correlation degree between the types of water resources utilization and the indicators of urban economic development.Thirdly,the quadratic regression model was adopted to analyze the impacts of industrial structure upon agricultural and industrial water,focusing on the relationship between urban economic development and domestic water consumption.The results showed that:(1)There was a large spatial difference in water use between the BeijingTianjin Hebei region,especially in the spatial imbalance between domestic water consumption and industrial water consumption,due to regional economic and development levels;(2) There was a high correlation between the index of urban economic development and the types of water resources utilization in Beijing Tianjin Hebei region,and the industrial structure had the greatest correlation with water resources utilization.Beijing′s domestic water consumption was significantly affected by urban economic development,while Tianjin′s was by the industrial water consumption,and Hebei was by the industrial and agricultural water consumption;(3) There was a better regression relationship between industrial structure and water consumption in Beijing Tianjin Hebei region (p<0.01),among which Beijing and Tianjin had the fastest growth rate of domestic water consumption,while the increase of water price has not played a role in restraining and reducing domestic water consumption in this region.
Beijing Tianjin Hebei region,located in the "capital circle" of China,has an extremely important strategic position.The shortage of water resources has become one of the factors that seriously restrict its economic and social developments.Based on the data of water resources utilization and urban economic development from 2000 to 2016,this study firstly investigated the spatiotemporal variations of quantity,structure and efficiency of water resources in Beijing Tianjin Hebei region with coefficient of variation and the Theil coefficient.Secondly,the grey correlation method was used to explore the correlation degree between the types of water resources utilization and the indicators of urban economic development.Thirdly,the quadratic regression model was adopted to analyze the impacts of industrial structure upon agricultural and industrial water,focusing on the relationship between urban economic development and domestic water consumption.The results showed that:(1)There was a large spatial difference in water use between the BeijingTianjin Hebei region,especially in the spatial imbalance between domestic water consumption and industrial water consumption,due to regional economic and development levels;(2) There was a high correlation between the index of urban economic development and the types of water resources utilization in Beijing Tianjin Hebei region,and the industrial structure had the greatest correlation with water resources utilization.Beijing′s domestic water consumption was significantly affected by urban economic development,while Tianjin′s was by the industrial water consumption,and Hebei was by the industrial and agricultural water consumption;(3) There was a better regression relationship between industrial structure and water consumption in Beijing Tianjin Hebei region (p<0.01),among which Beijing and Tianjin had the fastest growth rate of domestic water consumption,while the increase of water price has not played a role in restraining and reducing domestic water consumption in this region.
2019, 17(2):40-48.
Abstract:
The water resources security has always been a research hotspot.It is important to understand the utilization of water resources,as well as the sustainable use of water resources from production to consumption.Based on the perspectives of agriculture virtual water,this paper estimated the regional virtual water production from irrigation water and green water,and resident agriculture virtual water consumption from resident dietary consumption,and explored the flow characteristics of agriculture virtual water and its impacts on regional water resource with the production consumption mode in the Beijing Tianjin Hebei region.The results showed that:(1)During 2004-2015,the average annual production of virtual water was 35 31 billion m3,229 billion m3,160 billion m3 in Hebei,Tianjin and Beijing,respectively,and the annual average production of virtual water for livestock products was 2909 billion m3,240 billion m3,179 billion m3.Hebei and Tianjin's crop virtual water showed a downward trend but the trend was not statistically significant.Beijing's crop production virtual water appeared a downward trend.The virtual water of livestock products in Hebei and Tianjin showed anincreasing trend in the early period,then a decreasing trend,and finally a stable but continuous downward trend in Beijing.(2)During 2004-2015,the average annual virtual water consumption in Hebei,Tianjin and Beijing was 3437 billion m3,616 billion m3,and 983 billion m3,respectively.Those virtual water consumption all showed an upward trend.(3)Hebei Province exported virtual water,and its output showed a significant downward trend.Beijing and Tianjin were importers of virtual water,and their importing volumes were increasing.(4)The annual average water stress index presented a Hebei>Tianjin>Beijing pattern,water scarcity index Tianjin>Beijing>Hebei,and water self sufficiency rate Hebei>Tianjin>Beijing from 2004 to 2015.Beijing and Tianjin increasingly depended on external virtual water inputs.Beijing Tianjin Hebei are facing water shortage problems aswater resources were seriously overexploited.Improving agricultural water use efficiency,optimizing planting structure,and guiding rational dietary structures,and taking both production and consumption into account,are key countermeasures to solve the water problems in Beijing Tianjin Hebei region.
The water resources security has always been a research hotspot.It is important to understand the utilization of water resources,as well as the sustainable use of water resources from production to consumption.Based on the perspectives of agriculture virtual water,this paper estimated the regional virtual water production from irrigation water and green water,and resident agriculture virtual water consumption from resident dietary consumption,and explored the flow characteristics of agriculture virtual water and its impacts on regional water resource with the production consumption mode in the Beijing Tianjin Hebei region.The results showed that:(1)During 2004-2015,the average annual production of virtual water was 35 31 billion m3,229 billion m3,160 billion m3 in Hebei,Tianjin and Beijing,respectively,and the annual average production of virtual water for livestock products was 2909 billion m3,240 billion m3,179 billion m3.Hebei and Tianjin's crop virtual water showed a downward trend but the trend was not statistically significant.Beijing's crop production virtual water appeared a downward trend.The virtual water of livestock products in Hebei and Tianjin showed anincreasing trend in the early period,then a decreasing trend,and finally a stable but continuous downward trend in Beijing.(2)During 2004-2015,the average annual virtual water consumption in Hebei,Tianjin and Beijing was 3437 billion m3,616 billion m3,and 983 billion m3,respectively.Those virtual water consumption all showed an upward trend.(3)Hebei Province exported virtual water,and its output showed a significant downward trend.Beijing and Tianjin were importers of virtual water,and their importing volumes were increasing.(4)The annual average water stress index presented a Hebei>Tianjin>Beijing pattern,water scarcity index Tianjin>Beijing>Hebei,and water self sufficiency rate Hebei>Tianjin>Beijing from 2004 to 2015.Beijing and Tianjin increasingly depended on external virtual water inputs.Beijing Tianjin Hebei are facing water shortage problems aswater resources were seriously overexploited.Improving agricultural water use efficiency,optimizing planting structure,and guiding rational dietary structures,and taking both production and consumption into account,are key countermeasures to solve the water problems in Beijing Tianjin Hebei region.
2019, 17(2):49-54.
Abstract:
Freshwater salinization is an emerging environmental problem worldwide.It is especially prominent in the artificial landscape water in urban areas.High salinity landscape water body makes it hard for plants to grow,so that the algae gradually becomes the dominant population,affecting the beauty of the water.In this study,we used the flocculation method to simultaneously remove phosphorus and algae,so as to recover the landscape water body to the state before the algae bloom.In this paper,we studied the removal efficiency of 11 flocculants on TP and Chla (chlorophyll a).Among them,PAC showed good effect on TP removal,and CPAM could effectively remove algae.After the concentration gradient optimization experiment,we selected the optimal dosage of PAC and CPAM,and performed compounding experiment.The results of the compounding were as follows:when PAC was 10 mg/L and CPASM was 3 mg/L,the combination had the best removal effect.The average removal rate of TP was 92-52%,and that of Chla was 98-32%.
Freshwater salinization is an emerging environmental problem worldwide.It is especially prominent in the artificial landscape water in urban areas.High salinity landscape water body makes it hard for plants to grow,so that the algae gradually becomes the dominant population,affecting the beauty of the water.In this study,we used the flocculation method to simultaneously remove phosphorus and algae,so as to recover the landscape water body to the state before the algae bloom.In this paper,we studied the removal efficiency of 11 flocculants on TP and Chla (chlorophyll a).Among them,PAC showed good effect on TP removal,and CPAM could effectively remove algae.After the concentration gradient optimization experiment,we selected the optimal dosage of PAC and CPAM,and performed compounding experiment.The results of the compounding were as follows:when PAC was 10 mg/L and CPASM was 3 mg/L,the combination had the best removal effect.The average removal rate of TP was 92-52%,and that of Chla was 98-32%.
2019, 17(2):55-66.
Abstract:
The temporal and spatial distributions of land use/land cover change situations in Mengwa,Huaihe River from 2000 to 2014 were investigated based on land use dynamic index and transition matrix.Three scenarios (24 sub-scenarios),"Immigration" "Agriculture land reduction" and "Combined actions",were developed and simulated by CLUE-S model to predict future land use pattern under different policies and restrictions.The optimization and simulation results indicated that land use pattern in flood detention basins were greatly influenced by engineering works and policies.Among four kinds of land use patterns as forest,pond,agricultural land and residential areas,spatial distribution competition existed:the priority of forest was higher than pond,in the periphery of residential areas of upper and middle reaches,while pond was the highest in the surrounding areas of lower embankment and rivers,.The predicted and optimized land use patterns would have advantages in flood reduction,water resources conservation and ecological functions.
The temporal and spatial distributions of land use/land cover change situations in Mengwa,Huaihe River from 2000 to 2014 were investigated based on land use dynamic index and transition matrix.Three scenarios (24 sub-scenarios),"Immigration" "Agriculture land reduction" and "Combined actions",were developed and simulated by CLUE-S model to predict future land use pattern under different policies and restrictions.The optimization and simulation results indicated that land use pattern in flood detention basins were greatly influenced by engineering works and policies.Among four kinds of land use patterns as forest,pond,agricultural land and residential areas,spatial distribution competition existed:the priority of forest was higher than pond,in the periphery of residential areas of upper and middle reaches,while pond was the highest in the surrounding areas of lower embankment and rivers,.The predicted and optimized land use patterns would have advantages in flood reduction,water resources conservation and ecological functions.
2019, 17(2):67-74.
Abstract:
The over exploitation of groundwater has resulted in a series of environmental and geological problems,such as,the decline regional groundwater level,sparse vegetation along the Peacock river,and deterioration of water quality.It seriously limited the local economic development and human production and life in Korla city,Xinjiang.The dynamic monitoring data of groundwater in Korla city was used in this study to address this over exploitation problem with three methods,i.e.,water level dynamics method,exploitation coefficient method and cause effect method.It was founded that the buried depth of groundwater in Korla city increased with time.The maximum descending rate of groundwater level was 5-33 m/a from 2003 to 2017,and the maximum exploitation coefficient was 6-18 among all townships.The total over-exploitation areas of groundwater in Korla city was 819-86 km2,including severe over exploitation area of 709-98 km2 and moderate over exploitation areas of 109-88 km2.The scientific based and rational exploitation control plans and countermeasures were proposed to provide guidance for the rational utilization of water resources of groundwater of oasis cities in arid.
The over exploitation of groundwater has resulted in a series of environmental and geological problems,such as,the decline regional groundwater level,sparse vegetation along the Peacock river,and deterioration of water quality.It seriously limited the local economic development and human production and life in Korla city,Xinjiang.The dynamic monitoring data of groundwater in Korla city was used in this study to address this over exploitation problem with three methods,i.e.,water level dynamics method,exploitation coefficient method and cause effect method.It was founded that the buried depth of groundwater in Korla city increased with time.The maximum descending rate of groundwater level was 5-33 m/a from 2003 to 2017,and the maximum exploitation coefficient was 6-18 among all townships.The total over-exploitation areas of groundwater in Korla city was 819-86 km2,including severe over exploitation area of 709-98 km2 and moderate over exploitation areas of 109-88 km2.The scientific based and rational exploitation control plans and countermeasures were proposed to provide guidance for the rational utilization of water resources of groundwater of oasis cities in arid.
2019, 17(2):75-80.
Abstract:
As the amount of ecological flow is one of the important factors in maintain aquatic ecosystem,the accurate estimation of it has important practical significances.The Shaying River,a typical river in the Huai River Basin,was used in this study.In order to explore the advantages and disadvantages of five commonly used hydrological methods,the ecological flow was estimated based on the 44year natural daily streamflow data at Zhoukou hydrological station.The results showed that the Q50_Q90 method had the largest water demand and the Tennant method had the smallest.Q50_Q90 method would increase water pressure.Meanwhile,the simulation result of natural flow regime with different hydrological methods showed that the Tessman method,the Monthly Flow variation method and the Lyon method all had obvious advantages over the Q50_Q90 method and the Tennant method.It was found that the Tennant method and the Lyon method had the highest satisfaction rates than the other method,and the Lyon method had the highest satisfaction rates in dry hydrological years than other four methods.Therefore,the Lyon method was the most reasonable method to calculate the ecological flow in seasonal river,such as Shaying River.
As the amount of ecological flow is one of the important factors in maintain aquatic ecosystem,the accurate estimation of it has important practical significances.The Shaying River,a typical river in the Huai River Basin,was used in this study.In order to explore the advantages and disadvantages of five commonly used hydrological methods,the ecological flow was estimated based on the 44year natural daily streamflow data at Zhoukou hydrological station.The results showed that the Q50_Q90 method had the largest water demand and the Tennant method had the smallest.Q50_Q90 method would increase water pressure.Meanwhile,the simulation result of natural flow regime with different hydrological methods showed that the Tessman method,the Monthly Flow variation method and the Lyon method all had obvious advantages over the Q50_Q90 method and the Tennant method.It was found that the Tennant method and the Lyon method had the highest satisfaction rates than the other method,and the Lyon method had the highest satisfaction rates in dry hydrological years than other four methods.Therefore,the Lyon method was the most reasonable method to calculate the ecological flow in seasonal river,such as Shaying River.
2019, 17(2):81-88.
Abstract:
Combining automatic monitoring data and neural network method is one of the main methods to predict the chlorophyll a concentration in waterbody.However,the prediction accuracy and stability of the traditional BP neural network model are questionable due to the limitations of the local search with the gradient descent method.To solve this problem,the global search algorithm EMA was used to optimize BP neural network weights and thresholds to improve the chlorophyll a prediction efficiency.The partial derivative method was used to analyze the sensitivity of the input factor in prediction model,and then to simplify the number of input factors.The results showed that EMA could significantly improve the stability and accuracy of network training in the BP neural network prediction model for chlorophyll a concentration.The prediction accuracy ranged from ［0.364,0.978］ to ［0.917,0.983］,and the average prediction accuracy improved from 0.950 to 0.968.The predictive model was more stable using Dimopoulos sensitivity analysis to reduce the model input factor from 12 to 8.The average prediction accuracy decreased from 0.968 to 0.962 and the prediction accuracy ranged from ［0.917,0.983］to ［0.921,0.976］. Under the condition that the number of input factors was 8,the average prediction accuracy with the input factors selected by the sensitivity analysis of Dimopoulos method was significantly higher than that with the input factors based on traditional PCA method.The study results can provide reference for input factor optimization based on BP neural network on chlorophyll a prediction model to improve the stability of model prediction.
Combining automatic monitoring data and neural network method is one of the main methods to predict the chlorophyll a concentration in waterbody.However,the prediction accuracy and stability of the traditional BP neural network model are questionable due to the limitations of the local search with the gradient descent method.To solve this problem,the global search algorithm EMA was used to optimize BP neural network weights and thresholds to improve the chlorophyll a prediction efficiency.The partial derivative method was used to analyze the sensitivity of the input factor in prediction model,and then to simplify the number of input factors.The results showed that EMA could significantly improve the stability and accuracy of network training in the BP neural network prediction model for chlorophyll a concentration.The prediction accuracy ranged from ［0.364,0.978］ to ［0.917,0.983］,and the average prediction accuracy improved from 0.950 to 0.968.The predictive model was more stable using Dimopoulos sensitivity analysis to reduce the model input factor from 12 to 8.The average prediction accuracy decreased from 0.968 to 0.962 and the prediction accuracy ranged from ［0.917,0.983］to ［0.921,0.976］. Under the condition that the number of input factors was 8,the average prediction accuracy with the input factors selected by the sensitivity analysis of Dimopoulos method was significantly higher than that with the input factors based on traditional PCA method.The study results can provide reference for input factor optimization based on BP neural network on chlorophyll a prediction model to improve the stability of model prediction.
2019, 17(2):89-97.
Abstract:
As the longest river discharging into the Nansi Lake,the Dongyu River plays an important role on the water quality of the Nansi Lake.To better understand the relationship between the community structure of chironomid and eutrophication of the Dongyu River,the head shells of larvae preserved in the upper 2cm thick loose bottom sediments were investigated with eight samples collected in May 2013.A total of 30 Chironomus species were identified in the Dongyu River surface sediments.The main genus were composed of Glyptotendipes pallens type (20-42%), Cricotopus sylvestris type (18-23%), Chironomus plumosus type (15-24%),Tanytarsus mendax type (7-35%), Dicrotendipes nervosus type (7-12%), Chironomus anthracinus type (6-23%),and Polypedilum nubifer type (5-38%),accounting for 79-97% of the total counts.Based on the biodiversity index and principal component of the Dongyu River,the water body was in a mild to moderate pollution level.Redundancy analysis showed that NH3-N was the main water environmental factor resulting in the distribution of the chironomid in the Dongyu River,and the responses of different species of Chironomid to NH3-N were varied. It can also be inferred that the Dongyu River is a medium eutrophic river, according to the ecological characteristics of the chironomid combination,with serious pollution in the middle and lower reaches,which are the key areas for water pollution control.
As the longest river discharging into the Nansi Lake,the Dongyu River plays an important role on the water quality of the Nansi Lake.To better understand the relationship between the community structure of chironomid and eutrophication of the Dongyu River,the head shells of larvae preserved in the upper 2cm thick loose bottom sediments were investigated with eight samples collected in May 2013.A total of 30 Chironomus species were identified in the Dongyu River surface sediments.The main genus were composed of Glyptotendipes pallens type (20-42%), Cricotopus sylvestris type (18-23%), Chironomus plumosus type (15-24%),Tanytarsus mendax type (7-35%), Dicrotendipes nervosus type (7-12%), Chironomus anthracinus type (6-23%),and Polypedilum nubifer type (5-38%),accounting for 79-97% of the total counts.Based on the biodiversity index and principal component of the Dongyu River,the water body was in a mild to moderate pollution level.Redundancy analysis showed that NH3-N was the main water environmental factor resulting in the distribution of the chironomid in the Dongyu River,and the responses of different species of Chironomid to NH3-N were varied. It can also be inferred that the Dongyu River is a medium eutrophic river, according to the ecological characteristics of the chironomid combination,with serious pollution in the middle and lower reaches,which are the key areas for water pollution control.
2019, 17(2):98-106.
Abstract:
A typical monitoring area of the Hetao Irrigation District of Inner Mongolia was used in this study to explore the groundwater charactristics at different periods.The depth to water table,total dissolved solid (TDS) and eight major ions were continuously monitored from 05/2012 to 12/2015.The characteristics of depth to groundwater and TDS were analyzed with statistical methods,based on the filed observation data,for the entire monitoring period,non freezing thawing period and crop growth period,respectively.The results showed that:(1) 82% of the groundwater in the study area was brackish water.TDS was mostly between 1~2 g/L.The groundwater chemical type was HCO-3+Cl-Na++Mg2+.(2) There was a slightly positive correlation between depth to water table and TDS.However,the correlation coefficients between TDS and Cl,SO2-4,K++Na+ were relatively higher for all three periods,which implied that these ions had a great impact on TDS.(3) The correlation coefficients between Cl and TDS at three periods were crop growth period>non freezing thawing period>the entire monitoring period,indicating that concentration caused by evaporation and leaching played the dominant role in the variations of the groundwater chemical characteristics.
A typical monitoring area of the Hetao Irrigation District of Inner Mongolia was used in this study to explore the groundwater charactristics at different periods.The depth to water table,total dissolved solid (TDS) and eight major ions were continuously monitored from 05/2012 to 12/2015.The characteristics of depth to groundwater and TDS were analyzed with statistical methods,based on the filed observation data,for the entire monitoring period,non freezing thawing period and crop growth period,respectively.The results showed that:(1) 82% of the groundwater in the study area was brackish water.TDS was mostly between 1~2 g/L.The groundwater chemical type was HCO-3+Cl-Na++Mg2+.(2) There was a slightly positive correlation between depth to water table and TDS.However,the correlation coefficients between TDS and Cl,SO2-4,K++Na+ were relatively higher for all three periods,which implied that these ions had a great impact on TDS.(3) The correlation coefficients between Cl and TDS at three periods were crop growth period>non freezing thawing period>the entire monitoring period,indicating that concentration caused by evaporation and leaching played the dominant role in the variations of the groundwater chemical characteristics.
2019, 17(2):107-115.
Abstract:
The MODFLOW model was used to simulate groundwater flow in a typical irrigation area,Peoples' Victory Canal Irrigation District,in North China Plain,based on the hydrogeological conditions of the study area.The model parameters were well calibrated and model verification results showed that the simulation results could reasonably reflect the groundwater dynamics in the study area from 2012 to 2013.Under agricultural groundwater exploitation and climate conditions during 2012-2013 period,groundwater balance was in a negative equilibrium state.The spatial distribution of groundwater flow in 2030 under the future climate change scenarios (RCP4.5 scenario NorESM1 M model) was further predicted.The results showed that the groundwater level would continue to decline from 2013 to 2030,and the low groundwater level funnel area was gradually expanding.The spatial distribution of groundwater flow in 2030 was further expllored under different groundwater exploitation scenarios,i.e.,the exploitation quantity increased and decreased by 20%,respectively.According to the forecast results,a 20% reduction in groundwater exploitation was projected to ensure that the groundwater level could be raised and the funnel area could be reduced.However,an increase in exploitation would lead to an obvious increase in the groundwater funnel area.
The MODFLOW model was used to simulate groundwater flow in a typical irrigation area,Peoples' Victory Canal Irrigation District,in North China Plain,based on the hydrogeological conditions of the study area.The model parameters were well calibrated and model verification results showed that the simulation results could reasonably reflect the groundwater dynamics in the study area from 2012 to 2013.Under agricultural groundwater exploitation and climate conditions during 2012-2013 period,groundwater balance was in a negative equilibrium state.The spatial distribution of groundwater flow in 2030 under the future climate change scenarios (RCP4.5 scenario NorESM1 M model) was further predicted.The results showed that the groundwater level would continue to decline from 2013 to 2030,and the low groundwater level funnel area was gradually expanding.The spatial distribution of groundwater flow in 2030 was further expllored under different groundwater exploitation scenarios,i.e.,the exploitation quantity increased and decreased by 20%,respectively.According to the forecast results,a 20% reduction in groundwater exploitation was projected to ensure that the groundwater level could be raised and the funnel area could be reduced.However,an increase in exploitation would lead to an obvious increase in the groundwater funnel area.
2019, 17(2):116-122.
Abstract:
The Hanjiang River is the water source of the Middle Route of the South to North Water Transfers Project and other important diversion projects.A integrated water regulation of the Hanjiang River Basin is of great interests for the optimal allocation and regulation of water resources. This paper introduced a integrated water regulation model for water transfers projects and reservoir management to address this problem.The model divided the Hanjiang River Basin into a water resources regulation system,consisting of reservoirs on main stream and branches,water transfers projects,cities and control sections.The model was composed of three modules:information service module,controlling reservoir of Hanjiang main stream and tributary operation module,and subsection water resources dispatching and allocation module.Each module was then coupled to form the model.The model was modularized and can be easily extended.It also integrated the total water consumption,control index,water resources management system,and water quantity allocation program,and realized subsection and sub region water resource allocation and regulation targets.The model,optimization of artificial experiences，provided technical support for water resources regulation and management of Hanjiang River Basin.
The Hanjiang River is the water source of the Middle Route of the South to North Water Transfers Project and other important diversion projects.A integrated water regulation of the Hanjiang River Basin is of great interests for the optimal allocation and regulation of water resources. This paper introduced a integrated water regulation model for water transfers projects and reservoir management to address this problem.The model divided the Hanjiang River Basin into a water resources regulation system,consisting of reservoirs on main stream and branches,water transfers projects,cities and control sections.The model was composed of three modules:information service module,controlling reservoir of Hanjiang main stream and tributary operation module,and subsection water resources dispatching and allocation module.Each module was then coupled to form the model.The model was modularized and can be easily extended.It also integrated the total water consumption,control index,water resources management system,and water quantity allocation program,and realized subsection and sub region water resource allocation and regulation targets.The model,optimization of artificial experiences，provided technical support for water resources regulation and management of Hanjiang River Basin.
2019, 17(2):123-131.
Abstract:
In order to evaluate the situation of drainage network in a built-up area and propose a targeted multi-scale zoning optimization strategy for improving drainage capacity of pipelines,this paper constructed an urban integrated drainage model with InfoWorks ICM for the Dongcheng District of Beijng.The model was calibrated and validated with two measured rainfall event data.The results showed that the model had a high accuracy and was reliable.The model was then used to simulate the drainage capacity of the drainage network under four different rainfall scenarios of the recurrence periods of 1,3,5 and 10 years.The simulation results of the study area were analyzed in three scales:1.The proportions of pipeline lengths of urban scale pipeline networks with less than 1 year,1-3 years,3-5 years,5-10 years and 10 years were 52%,10%,4%,6% and 29% respectively;2.The drainage capacity of the functional zoning on the land was:park and green space≥residential area>commercial and administrative office area>business area;3.The proportions of pipeline length of main and secondary roads with less than 1 year,1-3 years,3-5 years,5-10 years and 10 years were 38%,9%,4%,7% and 42%,respectively.Based on the evaluation results of drainage capacity of drainage pipe network under different scales,the problems and causes of insufficient drainage capacity were diagnosed and analyzed,and a suitability optimization strategy for improving drainage capacity was expected for other old urban areas in China through systematic assessment and optimization of the pipeline network.
In order to evaluate the situation of drainage network in a built-up area and propose a targeted multi-scale zoning optimization strategy for improving drainage capacity of pipelines,this paper constructed an urban integrated drainage model with InfoWorks ICM for the Dongcheng District of Beijng.The model was calibrated and validated with two measured rainfall event data.The results showed that the model had a high accuracy and was reliable.The model was then used to simulate the drainage capacity of the drainage network under four different rainfall scenarios of the recurrence periods of 1,3,5 and 10 years.The simulation results of the study area were analyzed in three scales:1.The proportions of pipeline lengths of urban scale pipeline networks with less than 1 year,1-3 years,3-5 years,5-10 years and 10 years were 52%,10%,4%,6% and 29% respectively;2.The drainage capacity of the functional zoning on the land was:park and green space≥residential area>commercial and administrative office area>business area;3.The proportions of pipeline length of main and secondary roads with less than 1 year,1-3 years,3-5 years,5-10 years and 10 years were 38%,9%,4%,7% and 42%,respectively.Based on the evaluation results of drainage capacity of drainage pipe network under different scales,the problems and causes of insufficient drainage capacity were diagnosed and analyzed,and a suitability optimization strategy for improving drainage capacity was expected for other old urban areas in China through systematic assessment and optimization of the pipeline network.
2019, 17(2):132-139.
Abstract:
The typhoon storm has the characteristics of high intensity and concentrated rainfall.It is easy to form local destructive flood disasters in the middle and small sized watersheds of coastal areas.The distributed hydrological model based on high resolution topographic and geomorphic data is an effective way to forecast flood in small and medium sized basins.The Meixi River Basin in Minqing County of Fujian Province was selected as out study region.The China Flash Flood Model (CNFF-HM),based on the high resolution DEM,soil data,and land use data,was used to build the distributed hydrological model of the Meixi Basin.Fifty six hydrological events were used to calibrate and validate the model.The flood caused by the 'Niebert' typhoon,which occurred on 9 July 2016,was simulated. The result showed the model performance was good with a less than 20% error for flood peak flow,and a Nash Sutcliffe efficiency coefficient (NSE) of 0-96.Thus the model can reflect the flood characteristics caused by short-term heavy rainfall in the basin,and provide reliable technical support for disaster prevention and reduction in the basin.
The typhoon storm has the characteristics of high intensity and concentrated rainfall.It is easy to form local destructive flood disasters in the middle and small sized watersheds of coastal areas.The distributed hydrological model based on high resolution topographic and geomorphic data is an effective way to forecast flood in small and medium sized basins.The Meixi River Basin in Minqing County of Fujian Province was selected as out study region.The China Flash Flood Model (CNFF-HM),based on the high resolution DEM,soil data,and land use data,was used to build the distributed hydrological model of the Meixi Basin.Fifty six hydrological events were used to calibrate and validate the model.The flood caused by the 'Niebert' typhoon,which occurred on 9 July 2016,was simulated. The result showed the model performance was good with a less than 20% error for flood peak flow,and a Nash Sutcliffe efficiency coefficient (NSE) of 0-96.Thus the model can reflect the flood characteristics caused by short-term heavy rainfall in the basin,and provide reliable technical support for disaster prevention and reduction in the basin.
2019, 17(2):140-145.
Abstract:
How to further improve the accuracy of hydrological forecasting,reduce forecasting errors,better serve flood control and rescue and water resources dispatching is a hot topic in hydrology.A forecasting error correction model is constructed in this study to improve the forecasting accuracy,based on the similarity theory that the same main influencing factors of hydrological forecasting in similar watersheds result in the similarity of forecasting errors.Different forecasting periods were taken as a starting point in similar watersheds.The error correction factors were based on the quadratic orthogonal regression design.The coefficient of determination increased from 0-933 to 0-998 for the Nujiang Daojieba hydrological station application.The average absolute error of the flood peak flow decreased from 693 m3/s to 116 m3/s,and the average relative error of the flood peak flow decreased from 16% to 3%.The flood peak time of forecasting error reduced from an average of 5-4 hours to 0-9 hours,and the accuracy of the scheme was upgraded from Grade B to Grade A.The hydrological similar flood forecasting correction method proposed in this paper has the advantages of simple structure,easy calculation and significant correction effects,to imrpove the accuracy of flood forecasting. It is also applicable to the case where the water area ratios of different forecasting sections are not much different in similar watersheds,and the flooding process is not much different.
How to further improve the accuracy of hydrological forecasting,reduce forecasting errors,better serve flood control and rescue and water resources dispatching is a hot topic in hydrology.A forecasting error correction model is constructed in this study to improve the forecasting accuracy,based on the similarity theory that the same main influencing factors of hydrological forecasting in similar watersheds result in the similarity of forecasting errors.Different forecasting periods were taken as a starting point in similar watersheds.The error correction factors were based on the quadratic orthogonal regression design.The coefficient of determination increased from 0-933 to 0-998 for the Nujiang Daojieba hydrological station application.The average absolute error of the flood peak flow decreased from 693 m3/s to 116 m3/s,and the average relative error of the flood peak flow decreased from 16% to 3%.The flood peak time of forecasting error reduced from an average of 5-4 hours to 0-9 hours,and the accuracy of the scheme was upgraded from Grade B to Grade A.The hydrological similar flood forecasting correction method proposed in this paper has the advantages of simple structure,easy calculation and significant correction effects,to imrpove the accuracy of flood forecasting. It is also applicable to the case where the water area ratios of different forecasting sections are not much different in similar watersheds,and the flooding process is not much different.
2019, 17(2):146-156.
Abstract:
The leakage of large amount of precipitation was the main cause of surface water shortage in karst rocky desertification areas.The conversion of the leaking hard to use blue water into ecological green water for vegetation growth and utilization was a useful exploration to improve water resource utilization under current technical level.Based on the Blue Water & Green Water Theory and the Soil-Plant-Atmosphere Continuum (SPAC) Principle,the conversion of blue water into green water in non-urban areas of Guiyang city was simulated with the Water Cycle Model of EcoHAT System in this study.It was found that:(1) The green water in the study area accounted for less than 50% of the precipitation,which was far below the global average of 65%,and with great potential for conversion and utilization.(2) Increasing vegetation coverage and thickening soil layer could enhance the process converting the leakage blue water into ecological green water,and the effects of thickened soil layer was more significant than those of increasing vegetation.(3) If the vegetation coverage was increased to 56% or above,which was an threshed,the effects on leakage was then limited.The research results of this paper would provide an add value reference for improving water resources utilization in the similar rocky desertification areas.
The leakage of large amount of precipitation was the main cause of surface water shortage in karst rocky desertification areas.The conversion of the leaking hard to use blue water into ecological green water for vegetation growth and utilization was a useful exploration to improve water resource utilization under current technical level.Based on the Blue Water & Green Water Theory and the Soil-Plant-Atmosphere Continuum (SPAC) Principle,the conversion of blue water into green water in non-urban areas of Guiyang city was simulated with the Water Cycle Model of EcoHAT System in this study.It was found that:(1) The green water in the study area accounted for less than 50% of the precipitation,which was far below the global average of 65%,and with great potential for conversion and utilization.(2) Increasing vegetation coverage and thickening soil layer could enhance the process converting the leakage blue water into ecological green water,and the effects of thickened soil layer was more significant than those of increasing vegetation.(3) If the vegetation coverage was increased to 56% or above,which was an threshed,the effects on leakage was then limited.The research results of this paper would provide an add value reference for improving water resources utilization in the similar rocky desertification areas.
2019, 17(2):157-165.
Abstract:
Desert Highway in Xinjiang,we analyzed the test data of 20 groundwater samples in the study area in 2014 and explored the major controlling factors of the hydrochemical evolution processes along the highway by means of mathematical statistics,Piper triangular diagrams,Gibbs figure,correlation analysis,and ion ratios.The results showed that the major anions and cations in the shallow groundwater were SO42- and Na+.The total dissolved solids (TDS) concentration ranged from 543.61 to 10249.74 mg/L with an average value of 4087.58 mg/L.The pH ranged from 7.11 to 9.05 with an average value of 7.8 7.95% of the water samples had a total hardness above 450 mg/L.The major hydrochemical types of groundwater were SO4·Cl Na,SO4·Cl Na·Mg and SO4·Cl Na·Ca.SO42- and Na+ were the main sources of TDS,and they were mainly derived from rock salt or evaporite dissolution.All the major ions had good correlation with each other,and their sources were consistent.Atmospheric precipitation had little effect on the chemical composition of groundwater in the study area.The groundwater was mainly affected by evaporation and rock weathering.The main ion source in groundwater was greatly affected by the weathering and dissolution of silicate rock and evaporite rock.It was also affected by the dissolution of carbonate rock and cation exchange.
Desert Highway in Xinjiang,we analyzed the test data of 20 groundwater samples in the study area in 2014 and explored the major controlling factors of the hydrochemical evolution processes along the highway by means of mathematical statistics,Piper triangular diagrams,Gibbs figure,correlation analysis,and ion ratios.The results showed that the major anions and cations in the shallow groundwater were SO42- and Na+.The total dissolved solids (TDS) concentration ranged from 543.61 to 10249.74 mg/L with an average value of 4087.58 mg/L.The pH ranged from 7.11 to 9.05 with an average value of 7.8 7.95% of the water samples had a total hardness above 450 mg/L.The major hydrochemical types of groundwater were SO4·Cl Na,SO4·Cl Na·Mg and SO4·Cl Na·Ca.SO42- and Na+ were the main sources of TDS,and they were mainly derived from rock salt or evaporite dissolution.All the major ions had good correlation with each other,and their sources were consistent.Atmospheric precipitation had little effect on the chemical composition of groundwater in the study area.The groundwater was mainly affected by evaporation and rock weathering.The main ion source in groundwater was greatly affected by the weathering and dissolution of silicate rock and evaporite rock.It was also affected by the dissolution of carbonate rock and cation exchange.
2019, 17(2):166-172.
Abstract:
The detailed descriptions of the Zhangjiaping debris-flow source at different periods and its evolution process under different activity rates were investigated in this study with four remote sensing images,DEM,and GIS and RS techniques.It is predicted that the debris-flow will not generate more new sources in the future,but the existing collapses has a possibility of expansion.FLO-2D software was also used to simulate the flushing ranges and the degree of river blocking under three rainfall frequencies for the Zhangjiaping debrisflow.The research results can provide reference for the source prevention and control measures at Zhangjiaping debris-flow,and provide scientific guidance for post disaster reconstruction within the runout zone.
The detailed descriptions of the Zhangjiaping debris-flow source at different periods and its evolution process under different activity rates were investigated in this study with four remote sensing images,DEM,and GIS and RS techniques.It is predicted that the debris-flow will not generate more new sources in the future,but the existing collapses has a possibility of expansion.FLO-2D software was also used to simulate the flushing ranges and the degree of river blocking under three rainfall frequencies for the Zhangjiaping debrisflow.The research results can provide reference for the source prevention and control measures at Zhangjiaping debris-flow,and provide scientific guidance for post disaster reconstruction within the runout zone.
2019, 17(2):173-181.
Abstract:
Maiji District of the Tianshui city in Gansu Province is located in the Longxi Loess Plateau,northwest China.,The landslides are widely distributed on broken ground due to heavy rainfall and historical earthquakes.How to estimate the relationship between the sensitivity of landslides with different causes and the geomorphic evolution stage of ground is of great interests.This paper summarized the morphological features of landslides through detailed field investigation,and divided them into rainfall induced or earthquake induced.The parameters HI and K in the areaaltitude curve of the geomorphologic evolution theory were calculated to assess evolution stages and erosion extent of each catchments.Regional landslide susceptibility zoning was mapped.Combining with actual landslide distribution data,the ratio of seismic landslide and rainfall landslide in each sensitive zone were estimated.Furthermore,the correspondence between landslide distribution with different causes and geomorphologic evolution stage was discussed to verify the sensitivity zoning.Three conclusions were drawn:1) The high sensitivity partition with parameters of HI 0-35 to 0-6 accounted for 67-87% of the region;The moderate sensitivity partition with HI from 0.6 to 1 accounted for 21-33% of the region;and the low sensitivity partition with HI from 0 to 0.35 accounted for 10.8% of the region.2) The parameters HI and K were positively correlated.3) The ratio of the two type landslides areas to their sensitive area increased with sensitivity.The rainfall landslide mainly occurred in the moderate sensitivity partition and showed shallow landslide.The seismic landslide mainly occurred in the high sensitivity partition.
Maiji District of the Tianshui city in Gansu Province is located in the Longxi Loess Plateau,northwest China.,The landslides are widely distributed on broken ground due to heavy rainfall and historical earthquakes.How to estimate the relationship between the sensitivity of landslides with different causes and the geomorphic evolution stage of ground is of great interests.This paper summarized the morphological features of landslides through detailed field investigation,and divided them into rainfall induced or earthquake induced.The parameters HI and K in the areaaltitude curve of the geomorphologic evolution theory were calculated to assess evolution stages and erosion extent of each catchments.Regional landslide susceptibility zoning was mapped.Combining with actual landslide distribution data,the ratio of seismic landslide and rainfall landslide in each sensitive zone were estimated.Furthermore,the correspondence between landslide distribution with different causes and geomorphologic evolution stage was discussed to verify the sensitivity zoning.Three conclusions were drawn:1) The high sensitivity partition with parameters of HI 0-35 to 0-6 accounted for 67-87% of the region;The moderate sensitivity partition with HI from 0.6 to 1 accounted for 21-33% of the region;and the low sensitivity partition with HI from 0 to 0.35 accounted for 10.8% of the region.2) The parameters HI and K were positively correlated.3) The ratio of the two type landslides areas to their sensitive area increased with sensitivity.The rainfall landslide mainly occurred in the moderate sensitivity partition and showed shallow landslide.The seismic landslide mainly occurred in the high sensitivity partition.
2019, 17(2):182-188.
Abstract:
In recent years, environmental geological problems,such as,karst groundwater spring water flow attenuation,dryness,water source over exploitation and karst collapse,have become increasingly apparent in central and southern parts of Shandong Provinces.It is urgent to strengthen this research topic.The distribution,genetic types and typical hydrogeological characteristics of karst water strong run-off belts in the Tai'an Zhifang spring area were investigated in this study. In order to achieve the feasibility of rational development and protection of karst groundwater.The results showed that the karst water strong run-off belts was a network like strong karst water rich zone with a large regulation function and developed in the active alternating zone of shallow groundwater.The groundwater regime was stable,with a high rate of bore formation and obvious identification characteristics.It is an ideal place for the exploitation of karst water sources in this area.Investigating the hydrogeological conditions of the strong run-off belts system and mastering its laws provided an effective way to further explore the karst groundwater in the central and southern portions of Shandong.
In recent years, environmental geological problems,such as,karst groundwater spring water flow attenuation,dryness,water source over exploitation and karst collapse,have become increasingly apparent in central and southern parts of Shandong Provinces.It is urgent to strengthen this research topic.The distribution,genetic types and typical hydrogeological characteristics of karst water strong run-off belts in the Tai'an Zhifang spring area were investigated in this study. In order to achieve the feasibility of rational development and protection of karst groundwater.The results showed that the karst water strong run-off belts was a network like strong karst water rich zone with a large regulation function and developed in the active alternating zone of shallow groundwater.The groundwater regime was stable,with a high rate of bore formation and obvious identification characteristics.It is an ideal place for the exploitation of karst water sources in this area.Investigating the hydrogeological conditions of the strong run-off belts system and mastering its laws provided an effective way to further explore the karst groundwater in the central and southern portions of Shandong.
2019, 17(2):189-195.
Abstract:
The side inlet/outlet of pumped storage power station has bidirectional flow characteristics.The shape parameters of the side inlet/outlet have a great influence on its hydraulic characteristics,though the layout of the connected water conveyance tunnel will also affect the hydraulic characteristics of the side inlet/outlet.If the layout of the water conveyance tunnel is not reasonable,it may lead to hydraulic characteristics adverse to the inlet/outlet.The paper investigated the influences of different tunnel slope on the hydraulic characteristics of the inlet/outlet on the condition of outflow using the turbulence model of RSM for a side inlet/outlet,given that the shape of the inlet and outlet remained the same. then The condition of outflow included the flow pattern,non-uniformity of flow velocity,the head loss coefficient and the flow distribution.The results showed that when the tunnel slope equaled the vertical diffusion angle of the diffusion section,the flow pattern in the inlet/outlet could be improved.The range and volume ratio of the reverse-flow velocity area was the smallest,non-uniformity coefficient of flow velocity and the head loss coefficient were the smallest.Therefore,when the vertical diffusion angle of the inlet/outlet diffusing section was not large and each tunnel slope satisfied the topography and geological conditions,the tunnel slope was equal to the vertical diffusion angle of the diffusing section to obtain better hydraulic characteristics.
The side inlet/outlet of pumped storage power station has bidirectional flow characteristics.The shape parameters of the side inlet/outlet have a great influence on its hydraulic characteristics,though the layout of the connected water conveyance tunnel will also affect the hydraulic characteristics of the side inlet/outlet.If the layout of the water conveyance tunnel is not reasonable,it may lead to hydraulic characteristics adverse to the inlet/outlet.The paper investigated the influences of different tunnel slope on the hydraulic characteristics of the inlet/outlet on the condition of outflow using the turbulence model of RSM for a side inlet/outlet,given that the shape of the inlet and outlet remained the same. then The condition of outflow included the flow pattern,non-uniformity of flow velocity,the head loss coefficient and the flow distribution.The results showed that when the tunnel slope equaled the vertical diffusion angle of the diffusion section,the flow pattern in the inlet/outlet could be improved.The range and volume ratio of the reverse-flow velocity area was the smallest,non-uniformity coefficient of flow velocity and the head loss coefficient were the smallest.Therefore,when the vertical diffusion angle of the inlet/outlet diffusing section was not large and each tunnel slope satisfied the topography and geological conditions,the tunnel slope was equal to the vertical diffusion angle of the diffusing section to obtain better hydraulic characteristics.
2019, 17(2):196-201.
Abstract:
To accurately and quickly solve the optimal operation problem of cascade hydro-power stations is a challenge in the field of water conservancy.A new multi-strategy artificial bee colony algorithm was proposed in this study.In order to better balance the global search and local search capabilities of the algorithms,two representative solution search strategies were used in this new algorithm,and they were combined to form a new search strategy while retaining the original two solution search strategies.Therefore,the new algorithm contained three candidate solution search strategies in the process of searching new solutions,which was convenient to strengthen the adaptability to various optimization problems.The adaptability and feasibility of the new algorithm were tested in the classic benchmark function and applied to the optimal operation of cascade hydro-power stations.Experimental results showed that the new algorithm had the advantages of stronger adaptability and faster convergence speed.
To accurately and quickly solve the optimal operation problem of cascade hydro-power stations is a challenge in the field of water conservancy.A new multi-strategy artificial bee colony algorithm was proposed in this study.In order to better balance the global search and local search capabilities of the algorithms,two representative solution search strategies were used in this new algorithm,and they were combined to form a new search strategy while retaining the original two solution search strategies.Therefore,the new algorithm contained three candidate solution search strategies in the process of searching new solutions,which was convenient to strengthen the adaptability to various optimization problems.The adaptability and feasibility of the new algorithm were tested in the classic benchmark function and applied to the optimal operation of cascade hydro-power stations.Experimental results showed that the new algorithm had the advantages of stronger adaptability and faster convergence speed.
2019, 17(2):202-208.
Abstract:
The dynamic failure processes of a block of rock behind the powerhouse of a hydro-power plant was investigated using the universal distinct element code (UDEC),which is based on discrete element method (DEM),and the dynamic timehistory method.The result showed that the failure processes of rock slope without support can be divided into four stages:namely unsliding stage,slow sliding stage,accelerating stage and failure stage.That is to say the failure of rock slope under seismic load is a cumulative process.The axial force response curve of anchor showed a good correlation with the relative displacement of element around the anchor element,which indicated that the latter could be one of factors of the anchor reinforcement effects under earthquake.The optimal proposals for slope strengthening was suggested based on the cable axial force distribution pattern,and it could be used as a reference for the similar projects.
The dynamic failure processes of a block of rock behind the powerhouse of a hydro-power plant was investigated using the universal distinct element code (UDEC),which is based on discrete element method (DEM),and the dynamic timehistory method.The result showed that the failure processes of rock slope without support can be divided into four stages:namely unsliding stage,slow sliding stage,accelerating stage and failure stage.That is to say the failure of rock slope under seismic load is a cumulative process.The axial force response curve of anchor showed a good correlation with the relative displacement of element around the anchor element,which indicated that the latter could be one of factors of the anchor reinforcement effects under earthquake.The optimal proposals for slope strengthening was suggested based on the cable axial force distribution pattern,and it could be used as a reference for the similar projects.
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