Volume 17,Issue 5,2019 Table of Contents
1 Study on the river water rights confirmation and allocation based on watershed in county-level units
2019, 17(5):1-10.
Abstract:
River water rights determination is an important measure for efficient use of water resources.Based on the Hydro30 high precision global river network,and the county-level administrative unit of Qinghai Province as the basic confirmation unit for water rights.The calculation and allocation method of the annual average runoff,the annual average ecological and environmental water requirement,the water requirement forecast,and the control red line of the total water consumption were proposed.For the first time,the river ecological and environmental water requirement were divided into the minimum river ecological water demand and the river′s suitable ecological environment water demand.The control red line of the total water consumption at the county-level was determined using decomposition ratio method and water requirement adjustment method.Based on the control red line of the total water consumption,future water requirement,the available river water resources and groundwater,the county-level watertaking rights were determined.The county-level river water taking rights were determined by respecting historical water use and current water use principles,ecological equity principles,fairness and efficiency principles,sustainable use principles,and optimal allocation principles.For the confirmation unit that the river′s self-produced water quantity cannot meet the water demand,the confirmation unit could use the upstream transit water in the basin,but the upper limit of water withdrawal was still the control red line of the total water consumption.The maximum and suitable river water taking rights of 46 allocation unit in Qinghai Province in 2020 and 2030 were obtained (for example,the river water rights in Xining City).For the first time,river water taking right was confirmed and allocated in county-level units,which can provide reference for the determination of river water rights in other regions.River water rights determination is an important measure for efficient use of water resources.Based on the Hydro30 high precision global river network,and the county-level administrative unit of Qinghai Province as the basic confirmation unit for water rights.The calculation and allocation method of the annual average runoff,the annual average ecological and environmental water requirement,the water requirement forecast,and the control red line of the total water consumption were proposed.For the first time,the river ecological and environmental water requirement were divided into the minimum river ecological water demand and the river′s suitable ecological environment water demand.The control red line of the total water consumption at the county-level was determined using decomposition ratio method and water requirement adjustment method.Based on the control red line of the total water consumption,future water requirement,the available river water resources and groundwater,the county-level watertaking rights were determined.The county-level river water taking rights were determined by respecting historical water use and current water use principles,ecological equity principles,fairness and efficiency principles,sustainable use principles,and optimal allocation principles.For the confirmation unit that the river′s self-produced water quantity cannot meet the water demand,the confirmation unit could use the upstream transit water in the basin,but the upper limit of water withdrawal was still the control red line of the total water consumption.The maximum and suitable river water taking rights of 46 allocation unit in Qinghai Province in 2020 and 2030 were obtained (for example,the river water rights in Xining City).For the first time,river water taking right was confirmed and allocated in county-level units,which can provide reference for the determination of river water rights in other regions.
River water rights determination is an important measure for efficient use of water resources.Based on the Hydro30 high precision global river network,and the county-level administrative unit of Qinghai Province as the basic confirmation unit for water rights.The calculation and allocation method of the annual average runoff,the annual average ecological and environmental water requirement,the water requirement forecast,and the control red line of the total water consumption were proposed.For the first time,the river ecological and environmental water requirement were divided into the minimum river ecological water demand and the river′s suitable ecological environment water demand.The control red line of the total water consumption at the county-level was determined using decomposition ratio method and water requirement adjustment method.Based on the control red line of the total water consumption,future water requirement,the available river water resources and groundwater,the county-level watertaking rights were determined.The county-level river water taking rights were determined by respecting historical water use and current water use principles,ecological equity principles,fairness and efficiency principles,sustainable use principles,and optimal allocation principles.For the confirmation unit that the river′s self-produced water quantity cannot meet the water demand,the confirmation unit could use the upstream transit water in the basin,but the upper limit of water withdrawal was still the control red line of the total water consumption.The maximum and suitable river water taking rights of 46 allocation unit in Qinghai Province in 2020 and 2030 were obtained (for example,the river water rights in Xining City).For the first time,river water taking right was confirmed and allocated in county-level units,which can provide reference for the determination of river water rights in other regions.River water rights determination is an important measure for efficient use of water resources.Based on the Hydro30 high precision global river network,and the county-level administrative unit of Qinghai Province as the basic confirmation unit for water rights.The calculation and allocation method of the annual average runoff,the annual average ecological and environmental water requirement,the water requirement forecast,and the control red line of the total water consumption were proposed.For the first time,the river ecological and environmental water requirement were divided into the minimum river ecological water demand and the river′s suitable ecological environment water demand.The control red line of the total water consumption at the county-level was determined using decomposition ratio method and water requirement adjustment method.Based on the control red line of the total water consumption,future water requirement,the available river water resources and groundwater,the county-level watertaking rights were determined.The county-level river water taking rights were determined by respecting historical water use and current water use principles,ecological equity principles,fairness and efficiency principles,sustainable use principles,and optimal allocation principles.For the confirmation unit that the river′s self-produced water quantity cannot meet the water demand,the confirmation unit could use the upstream transit water in the basin,but the upper limit of water withdrawal was still the control red line of the total water consumption.The maximum and suitable river water taking rights of 46 allocation unit in Qinghai Province in 2020 and 2030 were obtained (for example,the river water rights in Xining City).For the first time,river water taking right was confirmed and allocated in county-level units,which can provide reference for the determination of river water rights in other regions.
2 Research and application of dynamic rainfall threshold based on China Flash Flood Hydrological Model
2019, 17(5):11-19.
Abstract:
Flash flood warning at catchment scale was determined by dynamic rainfall threshold using China Flash Flood Hydrological Model (CNFF),considering antecedent soil moistures,accumulated rainfall depths,rainfall intensities,rainfall temporal patterns,and topographies.Three typical catchments of different hydrological characteristics were selected in the Sichuan province as study area to assess the accuracy of CNFF for early warning flash floods.Results show that:（1） CNFF was suitable for flash flood simulation in the study area,and the qualifying ratios were over 90% in the selected catchments;（2）With rainfall durations of 1 h,3 h,and 6h,the critical rainfall thresholds were obtained as 20~250 mm,12~160 mm,6~140 mm for Ganchang catchment,Xining catchment,and Xinsheng catchment,respectively;（3）The qualifying ratios for flash flood warning were over 80% under different rainfall durations for all catchments.This study may provide technical support for early warning flash floods at catchment scales.
Flash flood warning at catchment scale was determined by dynamic rainfall threshold using China Flash Flood Hydrological Model (CNFF),considering antecedent soil moistures,accumulated rainfall depths,rainfall intensities,rainfall temporal patterns,and topographies.Three typical catchments of different hydrological characteristics were selected in the Sichuan province as study area to assess the accuracy of CNFF for early warning flash floods.Results show that:（1） CNFF was suitable for flash flood simulation in the study area,and the qualifying ratios were over 90% in the selected catchments;（2）With rainfall durations of 1 h,3 h,and 6h,the critical rainfall thresholds were obtained as 20~250 mm,12~160 mm,6~140 mm for Ganchang catchment,Xining catchment,and Xinsheng catchment,respectively;（3）The qualifying ratios for flash flood warning were over 80% under different rainfall durations for all catchments.This study may provide technical support for early warning flash floods at catchment scales.
3 Risk assessment of rainstorm waterlogging based on numerical simulation in Shenzhen Minzhi District
2019, 17(5):20-28.
Abstract:
Based on SWMM model and two-dimensional hydrodynamic model,a hydrodynamic coupling model for urban rainwater and flood was established in Shenzhen Minzhi District.The model was validated using historical data.The results showed that the model had good accuracy and reliability.The urban rainflood model was used to simulate and analyze the waterlogging situation in the Minzhi District.According to hazard factors and the affected area,risk assessment index system was established in the study area.ArcGIS technology and analytic hierarchy process method was used to evaluate the risk of waterlogging disaster in Minzhi District.The result of waterlogging risk assessment showed that the risk of waterlogging disasters in the cities was mainly affected by inundation.The high risk region were mainly located in downstream area of Minzhi River inside Minqiang Community,Minzhi Community and Xinniu Community,while the low risk area were mainly distributed in Minle Community,Mintai Community and Daling Community away from Minzhi River.
Based on SWMM model and two-dimensional hydrodynamic model,a hydrodynamic coupling model for urban rainwater and flood was established in Shenzhen Minzhi District.The model was validated using historical data.The results showed that the model had good accuracy and reliability.The urban rainflood model was used to simulate and analyze the waterlogging situation in the Minzhi District.According to hazard factors and the affected area,risk assessment index system was established in the study area.ArcGIS technology and analytic hierarchy process method was used to evaluate the risk of waterlogging disaster in Minzhi District.The result of waterlogging risk assessment showed that the risk of waterlogging disasters in the cities was mainly affected by inundation.The high risk region were mainly located in downstream area of Minzhi River inside Minqiang Community,Minzhi Community and Xinniu Community,while the low risk area were mainly distributed in Minle Community,Mintai Community and Daling Community away from Minzhi River.
4 Research on water resources carrying capacity based on ecological footprint——A case study of Beijing
2019, 17(5):29-36.
Abstract:
To analyze and evaluate the sustainable development status of regional water resources,this paper used framework of water resources ecological footprint system as foundation.This study introduced the breadth and depth of water resources footprint to distinguish water resources flow capital and stock capital,combined the actual situation of Beijing to calculate the ecological carrying capacity of water resources,and discussed the fitting prediction effect of the improved combination model of ARIMA and GRNN in water resources ecological footprint.Results showed that under the unsafe state of Beijing′s longterm water deficit,the depth of water resources in the study period is greater than 1,and the average water ecological footprint was 0.169 hm2/cap,which is about twice the average ecological carrying capacity of water resources.The three indicators,i.e.,water consumption per ten thousand yuan of value added by industry,ten thousand yuan,and ten thousand yuan GDP water added value of agricultural water use were important factors which influenced the ecological footprint of water resources of Beijing.The effect of ARIMA (3,2,and 1) and GRNN coupling model on the fitting and prediction of the ecological footprint of water resources in Beijing was better than that of ARIMA model alone.The prediction results can provide reference for the more effective protection and allocation of water resources in Beijing.
To analyze and evaluate the sustainable development status of regional water resources,this paper used framework of water resources ecological footprint system as foundation.This study introduced the breadth and depth of water resources footprint to distinguish water resources flow capital and stock capital,combined the actual situation of Beijing to calculate the ecological carrying capacity of water resources,and discussed the fitting prediction effect of the improved combination model of ARIMA and GRNN in water resources ecological footprint.Results showed that under the unsafe state of Beijing′s longterm water deficit,the depth of water resources in the study period is greater than 1,and the average water ecological footprint was 0.169 hm2/cap,which is about twice the average ecological carrying capacity of water resources.The three indicators,i.e.,water consumption per ten thousand yuan of value added by industry,ten thousand yuan,and ten thousand yuan GDP water added value of agricultural water use were important factors which influenced the ecological footprint of water resources of Beijing.The effect of ARIMA (3,2,and 1) and GRNN coupling model on the fitting and prediction of the ecological footprint of water resources in Beijing was better than that of ARIMA model alone.The prediction results can provide reference for the more effective protection and allocation of water resources in Beijing.
2019, 17(5):37-43.
Abstract:
As frequent flood disasters occurring in small and medium watersheds of China,exploring new type of urban rainfall runoff model is a hotspot in the current researches. By coupling hydrologic model with hydrodynamic model,urban flood inundation may be simulated at an improved computing speed.Meixi basin is taken as an case study area to explore the applicability of the coupled model in small and medium watersheds of China. The study results show that inundation depth is basically consistent with verification value,with no possibility of error due to water balance calculation.By analyzing inundation depth map and time to maximum depth,spatial distribution and temporal distribution of regional flood disaster can be obtained to support decision-making for flood management in small and medium watersheds. But the reliability of the model may be questioned to a certain extent owing to lack in hydrologic data of small and medium watersheds.
As frequent flood disasters occurring in small and medium watersheds of China,exploring new type of urban rainfall runoff model is a hotspot in the current researches. By coupling hydrologic model with hydrodynamic model,urban flood inundation may be simulated at an improved computing speed.Meixi basin is taken as an case study area to explore the applicability of the coupled model in small and medium watersheds of China. The study results show that inundation depth is basically consistent with verification value,with no possibility of error due to water balance calculation.By analyzing inundation depth map and time to maximum depth,spatial distribution and temporal distribution of regional flood disaster can be obtained to support decision-making for flood management in small and medium watersheds. But the reliability of the model may be questioned to a certain extent owing to lack in hydrologic data of small and medium watersheds.
2019, 17(5):44-49.
Abstract:
In order to further improve the accuracy of mid and long term runoff prediction,taking the runoff data series of 1959-2014 in Lanxi Hydrological Station for case study,the grey model and BP neural network model are applied to predict the runoff depth respectively,and the prediction results are corrected with the state probability derived from the Markov chain,and,furthermore,the corrected results of both models are coupled by least square method.The statistical descriptions of the corrected and combined prediction results show 12.72% in average relative error,11.70 in mean square deviation of better than the grey model and BP neural network model,and 90.91% of the prediction results,satisfying with the threshold of relative error. less than 20%.The shortcomings of the single model may be effectively overcome by applying the coupled model,and the prediction precision be further improved by adopting the corrected results based on the Markov chain.With more efficient fitting and more accurate prediction,the corrected and combined model suggested in this study is of practical value in prediction of the mid and long term runoff.
In order to further improve the accuracy of mid and long term runoff prediction,taking the runoff data series of 1959-2014 in Lanxi Hydrological Station for case study,the grey model and BP neural network model are applied to predict the runoff depth respectively,and the prediction results are corrected with the state probability derived from the Markov chain,and,furthermore,the corrected results of both models are coupled by least square method.The statistical descriptions of the corrected and combined prediction results show 12.72% in average relative error,11.70 in mean square deviation of better than the grey model and BP neural network model,and 90.91% of the prediction results,satisfying with the threshold of relative error. less than 20%.The shortcomings of the single model may be effectively overcome by applying the coupled model,and the prediction precision be further improved by adopting the corrected results based on the Markov chain.With more efficient fitting and more accurate prediction,the corrected and combined model suggested in this study is of practical value in prediction of the mid and long term runoff.
2019, 17(5):50-55.
Abstract:
In order to identify the temporal characteristics of regional rainfall and improve the prediction accuracy of annual precipitation,the periodic variation of annual precipitation in Huangshan City from 1957 to 2016 was analyzed based on Morlet wavelet.A series of annual precipitations of Huangshan City from 1957 to 2011 was adopted to establish the ARIMA model and the combined model of ARIMA with wavelet,and both models were applied to predict the annual precipitation of Huangshan City from 2012 to 2016.The results show that the annual precipitation in Huangshan City is mainly affected by the periodic fluctuations of 28 a,13 a and 5 a.The mean absolute percentage error of the predicted annual precipitations for the period of 2012-2016 is 19.8% by applying the ARIMA model, while that for the same period is 12.3% by applying the combined model,indicating better accuracy in simulating and predicting the annual precipitation in Huangshan City by applying the combined model.Significant errors can be found in predicting the annual precipitations of Huangshan City in 2012,2015 and 2016 as different mechanism of precipitation in these years with normal years, probably resulting from an impact of ENSO events on the precipitations.As providing the scientific foundation for the regional long-and mid-term hydrological forecasting,the achievement is of certain value in management of early warning of the regional flood/drought disasters.
In order to identify the temporal characteristics of regional rainfall and improve the prediction accuracy of annual precipitation,the periodic variation of annual precipitation in Huangshan City from 1957 to 2016 was analyzed based on Morlet wavelet.A series of annual precipitations of Huangshan City from 1957 to 2011 was adopted to establish the ARIMA model and the combined model of ARIMA with wavelet,and both models were applied to predict the annual precipitation of Huangshan City from 2012 to 2016.The results show that the annual precipitation in Huangshan City is mainly affected by the periodic fluctuations of 28 a,13 a and 5 a.The mean absolute percentage error of the predicted annual precipitations for the period of 2012-2016 is 19.8% by applying the ARIMA model, while that for the same period is 12.3% by applying the combined model,indicating better accuracy in simulating and predicting the annual precipitation in Huangshan City by applying the combined model.Significant errors can be found in predicting the annual precipitations of Huangshan City in 2012,2015 and 2016 as different mechanism of precipitation in these years with normal years, probably resulting from an impact of ENSO events on the precipitations.As providing the scientific foundation for the regional long-and mid-term hydrological forecasting,the achievement is of certain value in management of early warning of the regional flood/drought disasters.
2019, 17(5):56-63.
Abstract:
Reliable water level forecasting is essential for flood prevention decision-making and water resources management,which can effectively reduce the loss of flood and droughts disasters.In order to improve the accuracy of forecasting,a nonlinear autoregressive with exogenous inputs neural network (NARX) model based on wavelet analysis (DWT-NARX) was proposed and compared with BP neural network,and NARX neural network model.The daily inflow,outflow,water utilization and the previous daily water level of Hongze Lake were considered to forecast the water level of Hongze Lake.The results indicated that three models achieved good simulation results with higher accuracy when the leading time was short,such as 1 or 2 days.The results exhibited that Nash-Sutcliffe coefficient was higher than 0.9,and the qualified rates surpass was not less than 85%.When the prediction period was further increased to 3 days,the NARX model showed poor prediction and the water level changed greatly,while BP model suggest severe oscillations.In overall performance,the NARX and DWT-NARX models showed superiority in comparison of BP neural network,while DWT-NARX yields the best performance among all other models.The research results can provide a certain reference value for the water level forecast of Hongze Lake.
Reliable water level forecasting is essential for flood prevention decision-making and water resources management,which can effectively reduce the loss of flood and droughts disasters.In order to improve the accuracy of forecasting,a nonlinear autoregressive with exogenous inputs neural network (NARX) model based on wavelet analysis (DWT-NARX) was proposed and compared with BP neural network,and NARX neural network model.The daily inflow,outflow,water utilization and the previous daily water level of Hongze Lake were considered to forecast the water level of Hongze Lake.The results indicated that three models achieved good simulation results with higher accuracy when the leading time was short,such as 1 or 2 days.The results exhibited that Nash-Sutcliffe coefficient was higher than 0.9,and the qualified rates surpass was not less than 85%.When the prediction period was further increased to 3 days,the NARX model showed poor prediction and the water level changed greatly,while BP model suggest severe oscillations.In overall performance,the NARX and DWT-NARX models showed superiority in comparison of BP neural network,while DWT-NARX yields the best performance among all other models.The research results can provide a certain reference value for the water level forecast of Hongze Lake.
2019, 17(5):64-70.
Abstract:
The Soil Conservation Service Curve Number (SCS-CN) method is a widely used empirical hydrologic model.Determination of its parameters and spatial scale effect of parameters have important influences on the accuracy of runoff simulations.With the upstream area of Huaihe River as the research area,we analyzed the sensitivity of SCS-CN model [JP]parameters and further modified the model.Spatial scale effects of parameters were analyzed based on the runoff simulation results at nine spatial resolutions (100 m～2 000 m).The results show that the sensibility of the basin water storage capacity parameter b was higher than that of the initial abstraction ratio (λ),which should be calibrated in the model.The spatial resolutions of underlying surface features had an important effect on the calibrated parameter b,which showed an exponential decreasing trend as the pixel scale increased.The optimal spatial resolution of the modified SCS model was 250500 m.
The Soil Conservation Service Curve Number (SCS-CN) method is a widely used empirical hydrologic model.Determination of its parameters and spatial scale effect of parameters have important influences on the accuracy of runoff simulations.With the upstream area of Huaihe River as the research area,we analyzed the sensitivity of SCS-CN model [JP]parameters and further modified the model.Spatial scale effects of parameters were analyzed based on the runoff simulation results at nine spatial resolutions (100 m～2 000 m).The results show that the sensibility of the basin water storage capacity parameter b was higher than that of the initial abstraction ratio (λ),which should be calibrated in the model.The spatial resolutions of underlying surface features had an important effect on the calibrated parameter b,which showed an exponential decreasing trend as the pixel scale increased.The optimal spatial resolution of the modified SCS model was 250500 m.
2019, 17(5):71-80.
Abstract:
The construction and operation of Zhoukou sluice on Shaying river has caused great changes in the flowing regime of the lower reach,which has a significant impact on the [JP2]structure and function of the water ecosystem in the basin.In order to evaluate the hydrological changes of Zhoukou reach quantitatively,daily runoff data of Zhoukou gauging station from 1951 to 2016 is selected,and the degree [JP]of 33 hydrological alteration indexes and their ecological influences before and after the construction of Zhoukou sluice in the middle reaches of Shaying river were evaluated through Ranges of Variability Approach (RVA) method.The results indicate that:(1) after 1975,the operation of Zhoukou sluice,human activities had an intensified influence on the flow regime of Shaying River,and the median value for each month showed a significant downward trend;(2) the overall degree of hydrologic alteration of Zhoukou gauging station is 414%, which is a moderate change,and the most significant changes occurred on the average flow in November,the timing of annual 1day minimum discharge and the flow fall rates,which were [JP2]strong changes;(3) The water supply and demand of Shaying River are in serious contradiction,and the operation and dispatching of sluice has adverse effects on the stability of water ecosystem.Therefore,it is urgent to carry out ecological restoration of Shaying River,adjust river flow timely,and realize coordinated development of regional economy and water ecosystem.
The construction and operation of Zhoukou sluice on Shaying river has caused great changes in the flowing regime of the lower reach,which has a significant impact on the [JP2]structure and function of the water ecosystem in the basin.In order to evaluate the hydrological changes of Zhoukou reach quantitatively,daily runoff data of Zhoukou gauging station from 1951 to 2016 is selected,and the degree [JP]of 33 hydrological alteration indexes and their ecological influences before and after the construction of Zhoukou sluice in the middle reaches of Shaying river were evaluated through Ranges of Variability Approach (RVA) method.The results indicate that:(1) after 1975,the operation of Zhoukou sluice,human activities had an intensified influence on the flow regime of Shaying River,and the median value for each month showed a significant downward trend;(2) the overall degree of hydrologic alteration of Zhoukou gauging station is 414%, which is a moderate change,and the most significant changes occurred on the average flow in November,the timing of annual 1day minimum discharge and the flow fall rates,which were [JP2]strong changes;(3) The water supply and demand of Shaying River are in serious contradiction,and the operation and dispatching of sluice has adverse effects on the stability of water ecosystem.Therefore,it is urgent to carry out ecological restoration of Shaying River,adjust river flow timely,and realize coordinated development of regional economy and water ecosystem.
2019, 17(5):81-89.
Abstract:
In recent years,due to the irrational utilization of groundwater,soil salinization has occurred in some arid and semiarid regions of China.In this research,the spatial and temporal variations of groundwater depth and its main influencing factors were analyzed from 1990 to 2015 based on 67 monitoring wells in Yichang Irrigation Subdistrict.Statistical analysis,geostatistics and grey correlation analysis were applied to analyzing these data.The results reveal that:(1) the average phreatic level in Yichang Irrigation Sub-district has dropped by nearly 0.4 m in 26 years,and the average decline rate is 1.6 cm/a;(2) the optimal variogram of groundwater depth in the last 26 years has Gaussian, exponential and spherical model,however,it is dominated by the Gaussian model.The regional variation of groundwater depth has strong spatial correlation,and the variation ranges from 5 to 7 km;(3) the spatial interpolation results show that there has certain difference in the spatial distribution of groundwater depth in different periods,while the overall range is from 1.5 to 2.5 m;with an average proportion of 60%;(4) evaporation and groundwater recharge are the main driving factors for the variation of groundwater depth in Yichang Irrigation Sub-district based on the grey correlation analysis and partial correlation analysis.
In recent years,due to the irrational utilization of groundwater,soil salinization has occurred in some arid and semiarid regions of China.In this research,the spatial and temporal variations of groundwater depth and its main influencing factors were analyzed from 1990 to 2015 based on 67 monitoring wells in Yichang Irrigation Subdistrict.Statistical analysis,geostatistics and grey correlation analysis were applied to analyzing these data.The results reveal that:(1) the average phreatic level in Yichang Irrigation Sub-district has dropped by nearly 0.4 m in 26 years,and the average decline rate is 1.6 cm/a;(2) the optimal variogram of groundwater depth in the last 26 years has Gaussian, exponential and spherical model,however,it is dominated by the Gaussian model.The regional variation of groundwater depth has strong spatial correlation,and the variation ranges from 5 to 7 km;(3) the spatial interpolation results show that there has certain difference in the spatial distribution of groundwater depth in different periods,while the overall range is from 1.5 to 2.5 m;with an average proportion of 60%;(4) evaporation and groundwater recharge are the main driving factors for the variation of groundwater depth in Yichang Irrigation Sub-district based on the grey correlation analysis and partial correlation analysis.
2019, 17(5):90-99.
Abstract:
Pollution load estimation and source analysis are fundamental tasks of water environment management.Based on monitoring and statistical data,considering point source and nonpoint source pollution,water pollution loads and main pollution sources in 2016 were analyzed in the Yu River Basin,Shanxi Province.Based on the digital elevation model and positions of monitoring stations,the river basin was divided into six control units with support of Geographical Information System (GIS),an estimating method of pollution loss is proposed to calculate the pollution load from different pollution sources.The results showed that in 2016,7 299.52 tons of COD,1 163.56 tons of NH3-N, and 124.46 tons of TP were discharged into the Yuhe,of which 70.04%,86.45% and 68.00% were from point source pollution.The spatial analysis indicated that pollutants mainly came from the upstream of the Shili River and the Yu River,and was mainly ascribed to uncollected point source pollution,and contribution rates of COD,NH3-N and TP were 46%,80% and 49%,respectively.The results provided a scientific basis for water environment management in the Yu River Basin.
Pollution load estimation and source analysis are fundamental tasks of water environment management.Based on monitoring and statistical data,considering point source and nonpoint source pollution,water pollution loads and main pollution sources in 2016 were analyzed in the Yu River Basin,Shanxi Province.Based on the digital elevation model and positions of monitoring stations,the river basin was divided into six control units with support of Geographical Information System (GIS),an estimating method of pollution loss is proposed to calculate the pollution load from different pollution sources.The results showed that in 2016,7 299.52 tons of COD,1 163.56 tons of NH3-N, and 124.46 tons of TP were discharged into the Yuhe,of which 70.04%,86.45% and 68.00% were from point source pollution.The spatial analysis indicated that pollutants mainly came from the upstream of the Shili River and the Yu River,and was mainly ascribed to uncollected point source pollution,and contribution rates of COD,NH3-N and TP were 46%,80% and 49%,respectively.The results provided a scientific basis for water environment management in the Yu River Basin.
2019, 17(5):100-107.
Abstract:
In order to determine the key factors affecting the water quality of the water supply area of the South-to-North Water Transfer Project in Jiangsu Province,the water quality driving forces of the water supply area of the South-to-North Water Transfer Project in Jiangsu Province were studied.Based on the regional characteristics of the South-to-North Water Transfer Project in Jiangsu Province,and in view of the effectiveness of water pollution control,the level of economic and social development,the scale of industrial development,the carrying capacity of water resources,the scale of typical pollutants discharge,the investment in water pollution control and the policy of ecological environment were considered and 24 independent variable characterization indexes were established.Based on step-wise regression analysis method,the optimal regression equation of water quality driving factors showed that water consumption in domestic service industry and COD regional discharge had the most significant impact on water quality.Likewise,water use efficiency in irrigation canal system and investment in regional water pollution control among the positive driving factors had the greatest impact on water quality.Moreover,targeted water quality improvement measures were proposed to classify and quantify the pollutant discharge equivalent and its long-term management responsibility for forcing local governments to increase investment in water pollution control.In addition,to promote the agricultural water saving by raising water prices for reducing the agricultural pollutants discharge;to optimize water pollution control policies that strictly prohibited the direct discharge of sewage from domestic service industry;and to strengthen internal source governance for controlling siltation pollution diffusion were also suggested.
In order to determine the key factors affecting the water quality of the water supply area of the South-to-North Water Transfer Project in Jiangsu Province,the water quality driving forces of the water supply area of the South-to-North Water Transfer Project in Jiangsu Province were studied.Based on the regional characteristics of the South-to-North Water Transfer Project in Jiangsu Province,and in view of the effectiveness of water pollution control,the level of economic and social development,the scale of industrial development,the carrying capacity of water resources,the scale of typical pollutants discharge,the investment in water pollution control and the policy of ecological environment were considered and 24 independent variable characterization indexes were established.Based on step-wise regression analysis method,the optimal regression equation of water quality driving factors showed that water consumption in domestic service industry and COD regional discharge had the most significant impact on water quality.Likewise,water use efficiency in irrigation canal system and investment in regional water pollution control among the positive driving factors had the greatest impact on water quality.Moreover,targeted water quality improvement measures were proposed to classify and quantify the pollutant discharge equivalent and its long-term management responsibility for forcing local governments to increase investment in water pollution control.In addition,to promote the agricultural water saving by raising water prices for reducing the agricultural pollutants discharge;to optimize water pollution control policies that strictly prohibited the direct discharge of sewage from domestic service industry;and to strengthen internal source governance for controlling siltation pollution diffusion were also suggested.
2019, 17(5):108-114.
Abstract:
Watershed pollution load distribution is an important measure to implement watershed fine management.In order to quantitatively describe the significance of assessment indicators on the distribution of pollution load in river basin,the random forest algorithm was adopted to evaluate the importance of the selected indicators.The evaluation indices,which can reflect all the influence factors,were selected based on their importance,then,the weight coefficient of each indicator was further determined based on its score.The coupling model of pollution load distribution is constructed by combining the evaluation index system with the environmental gini coefficient model.Additionally, allocation plan of COD load was formulated based on control unit in the target Qingyi river basin (Xuchang Section).We found that the indicators,which fulfill the requirements ofimportance score,include per capita income,sewage production per unit of GDP,water [JP]consumption of industrial and enterprises,the amount of surface water resources and area of control-unit, and the scores are 13.97,9.65,8.77,5.21 and 1.09,respectively.The allocation plan of COD load in the river basin on 2020 was further formulated based on the coupling model,and the pollutant reduction and reduction rate of the control-unit QYH-3 are the largest,which are 617.14 t/a and 30.44 %,respectively.The allocation plan is reasonable for reflecting the actual situation of the basin.
Watershed pollution load distribution is an important measure to implement watershed fine management.In order to quantitatively describe the significance of assessment indicators on the distribution of pollution load in river basin,the random forest algorithm was adopted to evaluate the importance of the selected indicators.The evaluation indices,which can reflect all the influence factors,were selected based on their importance,then,the weight coefficient of each indicator was further determined based on its score.The coupling model of pollution load distribution is constructed by combining the evaluation index system with the environmental gini coefficient model.Additionally, allocation plan of COD load was formulated based on control unit in the target Qingyi river basin (Xuchang Section).We found that the indicators,which fulfill the requirements ofimportance score,include per capita income,sewage production per unit of GDP,water [JP]consumption of industrial and enterprises,the amount of surface water resources and area of control-unit, and the scores are 13.97,9.65,8.77,5.21 and 1.09,respectively.The allocation plan of COD load in the river basin on 2020 was further formulated based on the coupling model,and the pollutant reduction and reduction rate of the control-unit QYH-3 are the largest,which are 617.14 t/a and 30.44 %,respectively.The allocation plan is reasonable for reflecting the actual situation of the basin.
2019, 17(5):115-123.
Abstract:
In order to analyze the influences of Green-Ampt and constant infiltration models on the numerical simulation results of urban inundation,Fengxi New City s taken as a case study to simulate the inundation processing by a urban stormwater numerical model based on hydrological and hydrodynamic methods.Using the Green-Ampt model to calculate the runoff process,the water accumulation in study area is simulated.It is found that the simulation result shows a good agreement with the measured one,and the inundation point can be accurately simulated.The changes of the total water quantity and inundation areaare calculated by using these two different infiltration model with the return period of 1 a,2 a,5 a,10 a,20 a and 50 a respectively.The results show that when the accumulated water reaches its peak value under the different rainfall return period, the water quantity under Green-Ampt model is reduced by 28.41%、26.49%、26.39%、21.04%、17.28%、and 15.02% respectively compared with the constant infiltration model.The total area of water in Class III and above decreased by 31.5%,28.6%,28.3%,20.7%,16.3%,and 127% respectively.This study reveals that the changing law of the inundation degree in different infiltration models under different rainfall return periods,and is of great significance for the more reasonable implementation of numerical model simulation and urban stormwater management.
In order to analyze the influences of Green-Ampt and constant infiltration models on the numerical simulation results of urban inundation,Fengxi New City s taken as a case study to simulate the inundation processing by a urban stormwater numerical model based on hydrological and hydrodynamic methods.Using the Green-Ampt model to calculate the runoff process,the water accumulation in study area is simulated.It is found that the simulation result shows a good agreement with the measured one,and the inundation point can be accurately simulated.The changes of the total water quantity and inundation areaare calculated by using these two different infiltration model with the return period of 1 a,2 a,5 a,10 a,20 a and 50 a respectively.The results show that when the accumulated water reaches its peak value under the different rainfall return period, the water quantity under Green-Ampt model is reduced by 28.41%、26.49%、26.39%、21.04%、17.28%、and 15.02% respectively compared with the constant infiltration model.The total area of water in Class III and above decreased by 31.5%,28.6%,28.3%,20.7%,16.3%,and 127% respectively.This study reveals that the changing law of the inundation degree in different infiltration models under different rainfall return periods,and is of great significance for the more reasonable implementation of numerical model simulation and urban stormwater management.
2019, 17(5):124-130.
Abstract:
Clarification of pollutant compositions and pollution sources of groundwater in different areas can provide solid foundation for formulating specific groundwater resources management system and improving water quality.Because of significant differences in economic development level and groundwater resources development/utilization pattern,degree of water pollution and pollution compositions may vary greatly between urban areas and suburbs.Taking Jinshui District and Gongyi County of Zhengzhou for case study,the status of groundwater pollution in two regions is evaluated by applying principal component analysis.The results show that nitrate is the dominant pollutant in Gongyi,while sulfate and ammonia nitrogen are the dominant pollutants in Jinshui,resulting from more discharges from industrial and mining enterprises and farmlands in Gongyi,and more domestic sewages in Jinshui.In view of the different groundwater pollution statuses and sources in two regions,specific suggestions on protection and management of the groundwater resources are put forward.
Clarification of pollutant compositions and pollution sources of groundwater in different areas can provide solid foundation for formulating specific groundwater resources management system and improving water quality.Because of significant differences in economic development level and groundwater resources development/utilization pattern,degree of water pollution and pollution compositions may vary greatly between urban areas and suburbs.Taking Jinshui District and Gongyi County of Zhengzhou for case study,the status of groundwater pollution in two regions is evaluated by applying principal component analysis.The results show that nitrate is the dominant pollutant in Gongyi,while sulfate and ammonia nitrogen are the dominant pollutants in Jinshui,resulting from more discharges from industrial and mining enterprises and farmlands in Gongyi,and more domestic sewages in Jinshui.In view of the different groundwater pollution statuses and sources in two regions,specific suggestions on protection and management of the groundwater resources are put forward.
2019, 17(5):131-138.
Abstract:
The assessment of water environmental carrying capacity (WECC) is of great[JP] significance to the healthy and sustainable development of regional water environment and human society and economy.In order to study the WECC of Baoding City,10 evaluation indexes were selected based on correlation analysis and principal component analysis.A GA-NN evaluation model of back-propagation neural network (BP-NN) optimized by genetic algorithm (GA) was established and compared with BP-NN evaluation model.Finally,the evaluation model was applied for assessment of WECC.The results revealed that the WECC of Baoding City showed an increasing trend from 2001 to 2016.Although the carrying capacity of water environment increased,but it was still at a weak level.Compared with the unoptimized BPNN,the GA-NN evaluation model showed higher fitting accuracy,more stable fitting error and stronger generalization ability,and it can be used as a simple and effective method for evaluating the WECC.
The assessment of water environmental carrying capacity (WECC) is of great[JP] significance to the healthy and sustainable development of regional water environment and human society and economy.In order to study the WECC of Baoding City,10 evaluation indexes were selected based on correlation analysis and principal component analysis.A GA-NN evaluation model of back-propagation neural network (BP-NN) optimized by genetic algorithm (GA) was established and compared with BP-NN evaluation model.Finally,the evaluation model was applied for assessment of WECC.The results revealed that the WECC of Baoding City showed an increasing trend from 2001 to 2016.Although the carrying capacity of water environment increased,but it was still at a weak level.Compared with the unoptimized BPNN,the GA-NN evaluation model showed higher fitting accuracy,more stable fitting error and stronger generalization ability,and it can be used as a simple and effective method for evaluating the WECC.
2019, 17(5):139-147.
Abstract:
Located in Yun county of Yunnan,Dakongbang hot spring lies in the Yunnan-Tibet geothermal belt.In the hot spring area,the geothermal reservoir is mainly composed of the Lincang Granite with well-developed fractures.There are five spring orifices with water temperature ranging [JP2]from 88.3 to 96 ℃. Most of the cations in the hot water are K+, Na+, Ca2and Mg2+, and most of the anions are Cl-, SO42- and HCO3-. The hot water is characterized by HCO3Na type in hydrochemistry,and TDS 0.625～0.702 g/L, pH 6.7～9, H2SiO3 161.1～261 mg/L and F-5.85～16.1 mg/L. According to analysis of stable isotope, the δ2H and δ18O contents of the hot water samples indicate that the hot spring originates from precipitation. The elevation of the recharge area is estimated at 1 800m.Temperature of recharge area is about 3.6～7.2 ℃, and that of geothermal reservoir 143～181 ℃.The circulation depths of the thermal groundwater are approximately 2 858～3 496 m.The formation of the hot spring can be summarized as that recharging by precipitation in the surrounding mountain areas,the groundwater flows to deep and large fractures,heated by heat flows during deep circulation,then upwells as geothermal water along [JP]the fracture zones and finally crops out after mixing with cold shallow groundwater as boiling springs and fountains of high temperature.
Located in Yun county of Yunnan,Dakongbang hot spring lies in the Yunnan-Tibet geothermal belt.In the hot spring area,the geothermal reservoir is mainly composed of the Lincang Granite with well-developed fractures.There are five spring orifices with water temperature ranging [JP2]from 88.3 to 96 ℃. Most of the cations in the hot water are K+, Na+, Ca2and Mg2+, and most of the anions are Cl-, SO42- and HCO3-. The hot water is characterized by HCO3Na type in hydrochemistry,and TDS 0.625～0.702 g/L, pH 6.7～9, H2SiO3 161.1～261 mg/L and F-5.85～16.1 mg/L. According to analysis of stable isotope, the δ2H and δ18O contents of the hot water samples indicate that the hot spring originates from precipitation. The elevation of the recharge area is estimated at 1 800m.Temperature of recharge area is about 3.6～7.2 ℃, and that of geothermal reservoir 143～181 ℃.The circulation depths of the thermal groundwater are approximately 2 858～3 496 m.The formation of the hot spring can be summarized as that recharging by precipitation in the surrounding mountain areas,the groundwater flows to deep and large fractures,heated by heat flows during deep circulation,then upwells as geothermal water along [JP]the fracture zones and finally crops out after mixing with cold shallow groundwater as boiling springs and fountains of high temperature.
2019, 17(5):148-155.
Abstract:
Based on 81 samplings in August 2015,the characteristics in distribution of total dissolved solids (TDS) and hydrochemical types of confined groundwater in the north Tacheng Basin are identified,and the evolution mechanisms explored from the perspective of evaporation,leaching and ion exchange by applying the hydrochemical analysis methods such as analogue method,Gibbs plot,excess deuterium model,ion ratios,chloro alkaline index and sodium adsorption ratio (SAR).The results show that the confined groundwater with TDS less than 1.0 g/L and HCO3-Ca type water (or HCO3-Ca·Mg type water, HCO3-Ca·Na type water) are widely distributed in the study area.The TDS and hydrochemical types of confined groundwater present horizontal zonation in the direction of groundwater runoff.From recharge area to discharge area of the confined groundwater,the TDS gradually increases,and the hydrochemical type successively transfers from HCO3-Ca type water to SO4HCO3-Ca·Na type water and SO4Ca·Na type water.Hydrochemical composition of the confined groundwater mainly depends upon leaching and ion exchange.In upstream areas,hydrochemical composition of the confined groundwater is mainly affected by dissolution of carbonate mineral and positive cation exchange,while in the midstream and downstream areas,mainly affected by gypsum dissolution.In individual runoff paths,effect of the positive cation exchange on the hdyrochemical composition of groundwater is more significant than that of leaching.
Based on 81 samplings in August 2015,the characteristics in distribution of total dissolved solids (TDS) and hydrochemical types of confined groundwater in the north Tacheng Basin are identified,and the evolution mechanisms explored from the perspective of evaporation,leaching and ion exchange by applying the hydrochemical analysis methods such as analogue method,Gibbs plot,excess deuterium model,ion ratios,chloro alkaline index and sodium adsorption ratio (SAR).The results show that the confined groundwater with TDS less than 1.0 g/L and HCO3-Ca type water (or HCO3-Ca·Mg type water, HCO3-Ca·Na type water) are widely distributed in the study area.The TDS and hydrochemical types of confined groundwater present horizontal zonation in the direction of groundwater runoff.From recharge area to discharge area of the confined groundwater,the TDS gradually increases,and the hydrochemical type successively transfers from HCO3-Ca type water to SO4HCO3-Ca·Na type water and SO4Ca·Na type water.Hydrochemical composition of the confined groundwater mainly depends upon leaching and ion exchange.In upstream areas,hydrochemical composition of the confined groundwater is mainly affected by dissolution of carbonate mineral and positive cation exchange,while in the midstream and downstream areas,mainly affected by gypsum dissolution.In individual runoff paths,effect of the positive cation exchange on the hdyrochemical composition of groundwater is more significant than that of leaching.
2019, 17(5):156-165.
Abstract:
Due to the large area of agricultural irrigation in the Loess Plateau,the groundwater table in the plateau has been greatly increased and a large number of landslides have been induced.In the Heifangtai region of Gansu Province,dozens of loess landslides caused by irrigation has occurred.This paper studies the response law of landslide hazard and groundwater in Heifangtai region through field investigation and numerical simulation.The landslide in Heifangtai region has obvious geomorphological evolution characteristics.On this basis,the numerical model of Heitai platform hydrogeology is established.The simulation results show that the occurrence of loess landslide will affect the boundary conditions of the groundwater system,and increase the drainage of the Heitai groundwater system through the expanding seepage face.At the same time,because the irrigated area becomes smaller,the total recharge of the groundwater system is reduced.For a fixed recharge amount,the groundwater phreatic level first peaked with the continuation of the landslide,and then decreased to a level close to the 2004 level,and the cumulative volume of the landslide reached 4 600×104 m3.Considering that the groundwater level in 2004 is still high enough to cause landslides,the area of the Heitai will be reduced by less than 7.8 km2.If effective measures are not taken,the landslide will continue to occur and the risk of landslide disasters in the study area will continue for a long time.
Due to the large area of agricultural irrigation in the Loess Plateau,the groundwater table in the plateau has been greatly increased and a large number of landslides have been induced.In the Heifangtai region of Gansu Province,dozens of loess landslides caused by irrigation has occurred.This paper studies the response law of landslide hazard and groundwater in Heifangtai region through field investigation and numerical simulation.The landslide in Heifangtai region has obvious geomorphological evolution characteristics.On this basis,the numerical model of Heitai platform hydrogeology is established.The simulation results show that the occurrence of loess landslide will affect the boundary conditions of the groundwater system,and increase the drainage of the Heitai groundwater system through the expanding seepage face.At the same time,because the irrigated area becomes smaller,the total recharge of the groundwater system is reduced.For a fixed recharge amount,the groundwater phreatic level first peaked with the continuation of the landslide,and then decreased to a level close to the 2004 level,and the cumulative volume of the landslide reached 4 600×104 m3.Considering that the groundwater level in 2004 is still high enough to cause landslides,the area of the Heitai will be reduced by less than 7.8 km2.If effective measures are not taken,the landslide will continue to occur and the risk of landslide disasters in the study area will continue for a long time.
2019, 17(5):166-171.
Abstract:
Water inrush from large tunnels often occurs in Karst areas,which are rare in red layers where water is traditionally considered to be poor.As one of the key control projects of Yakang Expressway,Feixianguan Tunnel has a huge water inrush when it reaches the K23+708 tender section. The water inrush volume is up to 1.74×106 mL/s. After a periodic water inrush,the steady flow is about 3.48×105 mL/s.Taking the Feixianguan tunnel as an example,this paper combines the previous results of hydrochemical analysis of water gushing in the tunnel,using the self developed percolation test slot device,which was specially used to simulate the process of tunnel water gushing,the prototype of K23+658~883 segment (225 m) of Feixianguan tunnel to a certain proportion as a model,and two typical sections of Feixianguan syncline were selected for physical simulation test.Through the fitting analysis of the test water inflow and the comparison of the characteristics of the measured water gushing in the tunnel,two kinds of water inrush modes of along the axis and around the axis were verified,and the source and channel of the water gushing were determined.The experimental results showed that the model was stable and reliable,and the research method and results may use as guidance and reference for the future research of similar projects.
Water inrush from large tunnels often occurs in Karst areas,which are rare in red layers where water is traditionally considered to be poor.As one of the key control projects of Yakang Expressway,Feixianguan Tunnel has a huge water inrush when it reaches the K23+708 tender section. The water inrush volume is up to 1.74×106 mL/s. After a periodic water inrush,the steady flow is about 3.48×105 mL/s.Taking the Feixianguan tunnel as an example,this paper combines the previous results of hydrochemical analysis of water gushing in the tunnel,using the self developed percolation test slot device,which was specially used to simulate the process of tunnel water gushing,the prototype of K23+658~883 segment (225 m) of Feixianguan tunnel to a certain proportion as a model,and two typical sections of Feixianguan syncline were selected for physical simulation test.Through the fitting analysis of the test water inflow and the comparison of the characteristics of the measured water gushing in the tunnel,two kinds of water inrush modes of along the axis and around the axis were verified,and the source and channel of the water gushing were determined.The experimental results showed that the model was stable and reliable,and the research method and results may use as guidance and reference for the future research of similar projects.
2019, 17(5):172-179.
Abstract:
The Weihe River alluvial fan aquifer is an important groundwater source in Shijiazhuang City and plays an important role in urban water supply security.Study on groundwater hydrochemical characteristics and controlling factors can scientifically identify the natural and anthropogenic factors and can provide reasonable basis for groundwater security.In this paper,109 groundwater sample and 7 surface water sample were obtained to analyze sixteen chemical parameters using hydrochemical method and multivariate statistical method.The results indicated that the HCO3 and HCO3·SO4 facies widely distributed in the whole area.HCO3·Cl facies were mainly distributed in the southern area of the top of Hutuo River alluvial fan and in the Yicheng Wuji area of northern Hutuo River.The comparative analysis in different time periods revealed that groundwater chemistry evolved to more facies,with an increasing trend of groundwater facies affected by anthropogenic factors.The results obtained by principal component analysis exhibited that the evolution of groundwater in the area was mainly controlled by the water rock interaction and overexploitation of groundwater as well as sewage and manure.
The Weihe River alluvial fan aquifer is an important groundwater source in Shijiazhuang City and plays an important role in urban water supply security.Study on groundwater hydrochemical characteristics and controlling factors can scientifically identify the natural and anthropogenic factors and can provide reasonable basis for groundwater security.In this paper,109 groundwater sample and 7 surface water sample were obtained to analyze sixteen chemical parameters using hydrochemical method and multivariate statistical method.The results indicated that the HCO3 and HCO3·SO4 facies widely distributed in the whole area.HCO3·Cl facies were mainly distributed in the southern area of the top of Hutuo River alluvial fan and in the Yicheng Wuji area of northern Hutuo River.The comparative analysis in different time periods revealed that groundwater chemistry evolved to more facies,with an increasing trend of groundwater facies affected by anthropogenic factors.The results obtained by principal component analysis exhibited that the evolution of groundwater in the area was mainly controlled by the water rock interaction and overexploitation of groundwater as well as sewage and manure.
GAN Fuwan
,
,
ZHANG Huaguo
,
,
HUANG Yuming
,
,
QIN Lina
,
,
GAO Yang
,
,
XIAO Liang
,
2019, 17(5):180-187.
Abstract:
The correlation of variables of flood from trunk stream with those from a tributary varies with sample selection of synthetic floods,which has a certain impact on flood control design. In the case study of Guiping Shipping Hub,this paper applies Copula function to construct the joint distribution of three samples of synthetic floods, the annual flood peak of the trunk stream,Xunjiang, and that of the tributary,Yujiang, the annual flood peak of Xunjiang and the flow of Yujiang in the corresponding period,and the annual flood peak of Yujiang and the flow of Xunjiang in the corresponding period.Influences of three samples of synthetic floods on flood control design are evaluated by applying stochastic simulation of synthetic floods and derivation of flood control level through flood routing.The results show that the optimum Copula function fitted by the joint distribution of three samples of synthetic floods is Clayton Copula.The flood control level derived according to the synthetic flood of annual flood peak of Xunjiang and the flow of Yujiang in the corresponding period is more reasonable,neither overestimating nor underestimating flood risk,thus achieving a better balance between economy and safety.The derived flood control level for 100 year return period flood is 43.54 m,safer than the original design flood level determined by empirical method.By taking into account the correlation of flood from trunk stream with that from a tributary and the coupling relationshipbetween synthetic flood and flood routing,the Copula-Monte Carlo method adopted in this paper is considered to be more applicable to the flood control design.
The correlation of variables of flood from trunk stream with those from a tributary varies with sample selection of synthetic floods,which has a certain impact on flood control design. In the case study of Guiping Shipping Hub,this paper applies Copula function to construct the joint distribution of three samples of synthetic floods, the annual flood peak of the trunk stream,Xunjiang, and that of the tributary,Yujiang, the annual flood peak of Xunjiang and the flow of Yujiang in the corresponding period,and the annual flood peak of Yujiang and the flow of Xunjiang in the corresponding period.Influences of three samples of synthetic floods on flood control design are evaluated by applying stochastic simulation of synthetic floods and derivation of flood control level through flood routing.The results show that the optimum Copula function fitted by the joint distribution of three samples of synthetic floods is Clayton Copula.The flood control level derived according to the synthetic flood of annual flood peak of Xunjiang and the flow of Yujiang in the corresponding period is more reasonable,neither overestimating nor underestimating flood risk,thus achieving a better balance between economy and safety.The derived flood control level for 100 year return period flood is 43.54 m,safer than the original design flood level determined by empirical method.By taking into account the correlation of flood from trunk stream with that from a tributary and the coupling relationshipbetween synthetic flood and flood routing,the Copula-Monte Carlo method adopted in this paper is considered to be more applicable to the flood control design.
2019, 17(5):188-193.
Abstract:
Aiming of the complex non-linearity problem between environment and effect in concrete dam deformation prediction model and the low prediction accuracy of single support vector machine (SVM) model,an AdaBoost-SVM model for concrete dam deformation prediction was proposed.The model adopted the principle of minimizing structural risk and used the idea of learning algorithm for reference to improve the learning performance of the model for enhancing the generalization ability and prediction accuracy of the model.The prototype monitoring data of concrete dam displacement were trained and predicted by the AdaBoost-SVM prediction model,and the prediction results were compared with those of the single support vector machine model.The results showed that the mean square deviation of the prediction model based on AdaBoost-SVM was 0.5565, and the absolute average error was 0.40,while the prediction accuracy was one number higher than that of the single support vector machine model.In addition,compared with the single support vector machine prediction model,the enhanced model showed better stability in the prediction period.The model combined the advantages of lifting algorithm and support vector machine,and can be used as an effective method for deformation prediction of concrete dams.
Aiming of the complex non-linearity problem between environment and effect in concrete dam deformation prediction model and the low prediction accuracy of single support vector machine (SVM) model,an AdaBoost-SVM model for concrete dam deformation prediction was proposed.The model adopted the principle of minimizing structural risk and used the idea of learning algorithm for reference to improve the learning performance of the model for enhancing the generalization ability and prediction accuracy of the model.The prototype monitoring data of concrete dam displacement were trained and predicted by the AdaBoost-SVM prediction model,and the prediction results were compared with those of the single support vector machine model.The results showed that the mean square deviation of the prediction model based on AdaBoost-SVM was 0.5565, and the absolute average error was 0.40,while the prediction accuracy was one number higher than that of the single support vector machine model.In addition,compared with the single support vector machine prediction model,the enhanced model showed better stability in the prediction period.The model combined the advantages of lifting algorithm and support vector machine,and can be used as an effective method for deformation prediction of concrete dams.
2019, 17(5):194-201.
Abstract:
In the humidification process,the water retention characteristics and the humidification deformation characteristics of original loess interact with each other. The existing soilwater characteristic curve model mainly describes the correlation between the watercontaining state and the suction force.These models cannot fully reflect the water retention characteristics and the deformation characteristics of loess during humidification process.Therefore,the graded humidification tests were carried out in Xinjiang undisturbed loess using consolidation apparatus.Then a soil-water characteristic curve study,characterized by moistening level and suction was conducted.The test results showed that curve shapes of moistening level versus suction during humidification process under vertical pressure were alike in semi-common logarithmic coordinate system,which possessed two sections:flat section and steep drop section.The influence of vertical pressure was manifested mainly by the difference between initial suction force and slopes in the section of steep drop. Relationship curves of moistening level and suction under different vertical stress can be regressed as a power function.On basis of the test results, the soil-water characteristic curve model considered by moistening level and suction was proposed.Finally,the model was applied in the other areas of loess.The results validated the applicability of the model to compression state or unpressurized condition state of original loess with different initial moisture content as well as humidification process of remolded loess in compression state.
In the humidification process,the water retention characteristics and the humidification deformation characteristics of original loess interact with each other. The existing soilwater characteristic curve model mainly describes the correlation between the watercontaining state and the suction force.These models cannot fully reflect the water retention characteristics and the deformation characteristics of loess during humidification process.Therefore,the graded humidification tests were carried out in Xinjiang undisturbed loess using consolidation apparatus.Then a soil-water characteristic curve study,characterized by moistening level and suction was conducted.The test results showed that curve shapes of moistening level versus suction during humidification process under vertical pressure were alike in semi-common logarithmic coordinate system,which possessed two sections:flat section and steep drop section.The influence of vertical pressure was manifested mainly by the difference between initial suction force and slopes in the section of steep drop. Relationship curves of moistening level and suction under different vertical stress can be regressed as a power function.On basis of the test results, the soil-water characteristic curve model considered by moistening level and suction was proposed.Finally,the model was applied in the other areas of loess.The results validated the applicability of the model to compression state or unpressurized condition state of original loess with different initial moisture content as well as humidification process of remolded loess in compression state.
2019, 17(5):202-208.
Abstract:
Risk management in construction of hydropower engineering project is a complex system of multiparty cooperation and supply,in which resource conflict is the key jeopardy in the risk management process of construction enterprises.Aiming of the complexity and uncertainty of resource conflict risk of hydropower engineering programs,the set pair analysis theory was introduced,and a model for risk assessment and prediction of hydropower engineering programs resource conflict based on five element connection number was proposed.According to the resource conflict characteristics of hydropower engineering programs,the resource conflict risk evaluation system was established.The entropy weight method was used to estimate the weight of each evaluation index.The static risk evaluation model of identical,different,and counter risk evaluation was established by using five-element connection number,and the development trend of risk was predicted by partial connection number.The hydropower station in the upstream section of the main stream of a river basin is used as an example in the model for analysis purpose.The results show that the resource conflict risk level of the hydropower station is low,and the overall risk is gradually decreasing,but each sub-risk presents a wave like development trend,which is consistent with the actual situation,and verifies the feasibility of the model.
Risk management in construction of hydropower engineering project is a complex system of multiparty cooperation and supply,in which resource conflict is the key jeopardy in the risk management process of construction enterprises.Aiming of the complexity and uncertainty of resource conflict risk of hydropower engineering programs,the set pair analysis theory was introduced,and a model for risk assessment and prediction of hydropower engineering programs resource conflict based on five element connection number was proposed.According to the resource conflict characteristics of hydropower engineering programs,the resource conflict risk evaluation system was established.The entropy weight method was used to estimate the weight of each evaluation index.The static risk evaluation model of identical,different,and counter risk evaluation was established by using five-element connection number,and the development trend of risk was predicted by partial connection number.The hydropower station in the upstream section of the main stream of a river basin is used as an example in the model for analysis purpose.The results show that the resource conflict risk level of the hydropower station is low,and the overall risk is gradually decreasing,but each sub-risk presents a wave like development trend,which is consistent with the actual situation,and verifies the feasibility of the model.
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