Supervisor: Ministry of Water Resources of the People's Republic of China
Sponsor: Nanjing Institute of water resources, China Water Conservancy Society
Chief Editor: Zhang JianYun
Address: No.34, Hujuguan, Nanjing
Post Code: 210024
Tel: 025-85829770
Email: skxjz@nhri.cn
ISSN 1001-6791
CN 32-1309/P
Postal Code:28-146
Display Method:
2023, 34(2): 159-171.
doi: 10.14042/j.cnki.32.1309.2023.02.001
Abstract:
The hydrological forecast for the headwater area of Yellow River is of vital importance to the flood water resources utilization through optimal operation of cascade reservoirs over the Upper Yellow River such as Longyangxia and Liujiaxia, even to the prevention of flood and drought disasters for the entire Yellow River basin. However, the hydrological forecast in the source region is one of difficult problems in the current operational forecast of flood and discharge of Yellow River, due to the critical deficiency of ground-based rainfall observations and the lack of special hydrological model for high and cold mountain areas. This paper first reviewed the domestic and international related studies and then demonstrated the current status and technical level of hydrological forecast in the headwater area of Yellow River from three aspects including precipitation observation and precipitation forecast over ungauged areas with high altitudes, construction of hydrological model in cold regions and integration of meteorological and hydrological coupling forecast system, and meteorological genesis and formation mechanism of plateau precipitation occurrence. Subsequently, several key scientific issues existed in current hydrological operation forecast are systematically analyzed. Finally, it is suggested that the future studies of hydrological forecast in the headwater area of Yellow River focus on several important directions, such as the new-generation multi-source precipitation information fusion and assimilation, the development of specific hydrologic model for high and cold regions, the seamless ensemble forecast technique based on the meteorological and hydrological coupling, the analysis of multiple weather systems triggering heavy precipitation and continuous overcast rain.
The hydrological forecast for the headwater area of Yellow River is of vital importance to the flood water resources utilization through optimal operation of cascade reservoirs over the Upper Yellow River such as Longyangxia and Liujiaxia, even to the prevention of flood and drought disasters for the entire Yellow River basin. However, the hydrological forecast in the source region is one of difficult problems in the current operational forecast of flood and discharge of Yellow River, due to the critical deficiency of ground-based rainfall observations and the lack of special hydrological model for high and cold mountain areas. This paper first reviewed the domestic and international related studies and then demonstrated the current status and technical level of hydrological forecast in the headwater area of Yellow River from three aspects including precipitation observation and precipitation forecast over ungauged areas with high altitudes, construction of hydrological model in cold regions and integration of meteorological and hydrological coupling forecast system, and meteorological genesis and formation mechanism of plateau precipitation occurrence. Subsequently, several key scientific issues existed in current hydrological operation forecast are systematically analyzed. Finally, it is suggested that the future studies of hydrological forecast in the headwater area of Yellow River focus on several important directions, such as the new-generation multi-source precipitation information fusion and assimilation, the development of specific hydrologic model for high and cold regions, the seamless ensemble forecast technique based on the meteorological and hydrological coupling, the analysis of multiple weather systems triggering heavy precipitation and continuous overcast rain.
2023, 34(2): 172-181.
doi: 10.14042/j.cnki.32.1309.2023.02.002
Abstract:
In recent years, the risk of extreme super rainstorm in megacities coupled with big flood in rivers has been increasing, which caused heavy casualties and property losses. It is necessary to carry out joint prevention and control measurements to cope with river flood and urban waterlogging disaster chains. At present, it is an urgent need to integrate multidisciplinary theories and methods of meteorological science, hydrological science, information technology, disaster prevention and mitigation technology, to solve the key scientific and technological issues. The key scientific issue is the combination mechanism of river-urban flood and the risk transmission rule of disaster chain. Besides, there are four key technological issues : ① To integrate the river and urban meteorological-hydrological observation facilities into a collaborative one to monitor and forecast the flood risk. ② Intelligent early warning and directional message broadcasting technology for river flood and urban waterlogging disaster chain. ③ Coupled simulation of river-urban flood and demonstration of joint prevention and control scenarios. ④ Intelligent decision-making technology for river-urban joint flood control and emergency plan preparation. Based on the collaborative observation of meteorology and hydrology, social and economic multi-source information convergence analysis, and disaster deduction model, an emergency command and decision support system could be built for joint prevention and control of river-urban flood. The system highlights real-time, dynamic assessment, precision and intelligence to support the whole-process river-urban flood regulation. It could provide technical support for flood forecasting, early warning, scenario-demonstration and emergency plan preparation in megacities.
In recent years, the risk of extreme super rainstorm in megacities coupled with big flood in rivers has been increasing, which caused heavy casualties and property losses. It is necessary to carry out joint prevention and control measurements to cope with river flood and urban waterlogging disaster chains. At present, it is an urgent need to integrate multidisciplinary theories and methods of meteorological science, hydrological science, information technology, disaster prevention and mitigation technology, to solve the key scientific and technological issues. The key scientific issue is the combination mechanism of river-urban flood and the risk transmission rule of disaster chain. Besides, there are four key technological issues : ① To integrate the river and urban meteorological-hydrological observation facilities into a collaborative one to monitor and forecast the flood risk. ② Intelligent early warning and directional message broadcasting technology for river flood and urban waterlogging disaster chain. ③ Coupled simulation of river-urban flood and demonstration of joint prevention and control scenarios. ④ Intelligent decision-making technology for river-urban joint flood control and emergency plan preparation. Based on the collaborative observation of meteorology and hydrology, social and economic multi-source information convergence analysis, and disaster deduction model, an emergency command and decision support system could be built for joint prevention and control of river-urban flood. The system highlights real-time, dynamic assessment, precision and intelligence to support the whole-process river-urban flood regulation. It could provide technical support for flood forecasting, early warning, scenario-demonstration and emergency plan preparation in megacities.
2023, 34(2): 182-196.
doi: 10.14042/j.cnki.32.1309.2023.02.003
Abstract:
To analyze the spatio-temporal distribution pattern of precipitation in China, the trend and mutation characteristics of the annual precipitation, as well as the temporal and spatial evolution of the intra-annual distribution, are summarized and analyzed using multiple methods based on the fused monthly precipitation monitoring data of the water conservancy department and the meteorological department of 4 177 stations from 1956 to 2016. These methods include the Mann-Kendall test, PETTITT test, and vector algorithm for intra-annual distribution, which explores the distribution pattern of several indices, including the precipitation-concentration degree, precipitation-concentration period, and the proportion indices of the maximum accumulated precipitation in four months to one year. The following conclusions are drawn : ① The temporal and spatial distribution of precipitation across China is not uniform. In general, the annual precipitation decreases, and the concentration of annual precipitation distribution increases from southeast to northwest; the changing trend of the annual precipitation at the stations shows a strong zonality with three bands of "increase-decrease-increase" from the southeast to the northwest; the bands showing a significant increase are located in the Southeast and Western China, and the bands showing a significant decrease are located in the central region, stretching from the northeast to the southwest to the border; and abrupt changes are often accompanied with the trend changes of the annual precipitation, of which most sites occur in the 1980s. ② Along the 200 and 400 mm annual precipitation contours, one band shows "flood season precipitation reduction" with strong temporal variation in North China. On the monthly scale, the proportion of precipitation in the flood season of the station decreases, and it increases in the non-flood season, while the opposite is true on the daily scale. The amplitude of accumulated precipitation for 3—7 consecutive days increases, suggesting that the extreme degree of precipitation events is increasing. ③ The changes in the precipitation series and the changes in the runoff series are well synchronized. The annual precipitation in Northwest and Southeast China shows an increasing trend, and the statistical discharge of the typical hydrological stations increases synchronously. However, the stations at which the annual precipitation decreases significantly and where the proportion indices of the maximum accumulated precipitation in four months to one year declines more than 10%, are concentrated in the non-humid areas of Northern China, such as the Liaohe River basin, Haihe River basin, and Yellow River basin. In these regions, the statistical discharge of the hydrological stations has decreased significantly.
To analyze the spatio-temporal distribution pattern of precipitation in China, the trend and mutation characteristics of the annual precipitation, as well as the temporal and spatial evolution of the intra-annual distribution, are summarized and analyzed using multiple methods based on the fused monthly precipitation monitoring data of the water conservancy department and the meteorological department of 4 177 stations from 1956 to 2016. These methods include the Mann-Kendall test, PETTITT test, and vector algorithm for intra-annual distribution, which explores the distribution pattern of several indices, including the precipitation-concentration degree, precipitation-concentration period, and the proportion indices of the maximum accumulated precipitation in four months to one year. The following conclusions are drawn : ① The temporal and spatial distribution of precipitation across China is not uniform. In general, the annual precipitation decreases, and the concentration of annual precipitation distribution increases from southeast to northwest; the changing trend of the annual precipitation at the stations shows a strong zonality with three bands of "increase-decrease-increase" from the southeast to the northwest; the bands showing a significant increase are located in the Southeast and Western China, and the bands showing a significant decrease are located in the central region, stretching from the northeast to the southwest to the border; and abrupt changes are often accompanied with the trend changes of the annual precipitation, of which most sites occur in the 1980s. ② Along the 200 and 400 mm annual precipitation contours, one band shows "flood season precipitation reduction" with strong temporal variation in North China. On the monthly scale, the proportion of precipitation in the flood season of the station decreases, and it increases in the non-flood season, while the opposite is true on the daily scale. The amplitude of accumulated precipitation for 3—7 consecutive days increases, suggesting that the extreme degree of precipitation events is increasing. ③ The changes in the precipitation series and the changes in the runoff series are well synchronized. The annual precipitation in Northwest and Southeast China shows an increasing trend, and the statistical discharge of the typical hydrological stations increases synchronously. However, the stations at which the annual precipitation decreases significantly and where the proportion indices of the maximum accumulated precipitation in four months to one year declines more than 10%, are concentrated in the non-humid areas of Northern China, such as the Liaohe River basin, Haihe River basin, and Yellow River basin. In these regions, the statistical discharge of the hydrological stations has decreased significantly.
2023, 34(2): 197-208.
doi: 10.14042/j.cnki.32.1309.2023.02.004
Abstract:
To address common issues in urban catchment-scale rainfall-runoff simulations, such as inadequate topographic and drainage data, concentrated flooding on the road area, and the poor calculation accuracy or low calculation efficiency of the existing flooding models, a partition adaptive model based on the concept of plot generalization simulation and road networks fine simulation is proposed. For plots with insufficient data, sub-catchment units are divided, and the hydrological generalization method is used to calculate the runoff generation and concentration process. For the road area, fine grid division is carried out, and the two-dimensional hydrodynamic method is used to simulate the flow movement process. Both methods are coupled with the pipe network model to jointly drive the pipe network model to perform the confluence process calculation. The core demonstration area of Fengxi New Town in Xixian New Area is used as the research object to build a partition model. Besides, the full-distributed model with the study area discretized by fine grids and the semi-distributed model with the study area discretized by coarser sub-catchments are applied in the same area for comparison. The results show that : ① The partition model has the advantage of comprehensively considering the drainage of plot drainage and runoff process, and can simulate the inundation process in low-lying areas of road under the combined effect of surface runoff and pipe network overflow, which conforms to the actual rainfall flow motion. ② Compared with the semi-distributed model, the partition model can better simulate the process of water accumulation in the road area by using fine grids. ③ Since the calculation task of the partition model is less than that of the full distribution model, simulation time can be reduced by 28.2%—73.5% under different return periods. The new partition model effectively overcomes limitations of data conditions and computing power, and can provide a new coupling simulation idea for urban flood simulation.
To address common issues in urban catchment-scale rainfall-runoff simulations, such as inadequate topographic and drainage data, concentrated flooding on the road area, and the poor calculation accuracy or low calculation efficiency of the existing flooding models, a partition adaptive model based on the concept of plot generalization simulation and road networks fine simulation is proposed. For plots with insufficient data, sub-catchment units are divided, and the hydrological generalization method is used to calculate the runoff generation and concentration process. For the road area, fine grid division is carried out, and the two-dimensional hydrodynamic method is used to simulate the flow movement process. Both methods are coupled with the pipe network model to jointly drive the pipe network model to perform the confluence process calculation. The core demonstration area of Fengxi New Town in Xixian New Area is used as the research object to build a partition model. Besides, the full-distributed model with the study area discretized by fine grids and the semi-distributed model with the study area discretized by coarser sub-catchments are applied in the same area for comparison. The results show that : ① The partition model has the advantage of comprehensively considering the drainage of plot drainage and runoff process, and can simulate the inundation process in low-lying areas of road under the combined effect of surface runoff and pipe network overflow, which conforms to the actual rainfall flow motion. ② Compared with the semi-distributed model, the partition model can better simulate the process of water accumulation in the road area by using fine grids. ③ Since the calculation task of the partition model is less than that of the full distribution model, simulation time can be reduced by 28.2%—73.5% under different return periods. The new partition model effectively overcomes limitations of data conditions and computing power, and can provide a new coupling simulation idea for urban flood simulation.
2023, 34(2): 209-217.
doi: 10.14042/j.cnki.32.1309.2023.02.005
Abstract:
Urban waterlogging due to extreme precipitation presents an increasingly serious challenge. Pooling of large volumes of surface water can result in flooding of underground spaces. However, there remains limited studies on flooding of underground spaces through the application of hydrological and hydrodynamic models. This study examined flooding in an urban district of Zhengzhou City, China during an extreme rainstorm event on 20th July, 2021. An integrated simulation model of regional surface and underground spaces was established based on InfoWorks Integrated Catchment Model (ICM) software. The generalized reservoir and hydraulic connectivity methods were used to simulate underground spaces. Factors contributing to the initiation and development of flooding of underground spaces were analyzed. The results showed that underground waterlogging was less conducive to alleviation of surface water ponding. The advantages of the generalized reservoir method were shown to be its relative simplicity and feasibility, whereas that of the hydraulic connection method was its detailed representation of underground flooding. Both the cumulative quantity of rainfall and rainfall intensity were shown to have important effects on underground inundation. The results of this study can help to improve urban stormwater forecasting and warning systems, and provide a theoretical basis for regional disaster prevention and reduction.
Urban waterlogging due to extreme precipitation presents an increasingly serious challenge. Pooling of large volumes of surface water can result in flooding of underground spaces. However, there remains limited studies on flooding of underground spaces through the application of hydrological and hydrodynamic models. This study examined flooding in an urban district of Zhengzhou City, China during an extreme rainstorm event on 20th July, 2021. An integrated simulation model of regional surface and underground spaces was established based on InfoWorks Integrated Catchment Model (ICM) software. The generalized reservoir and hydraulic connectivity methods were used to simulate underground spaces. Factors contributing to the initiation and development of flooding of underground spaces were analyzed. The results showed that underground waterlogging was less conducive to alleviation of surface water ponding. The advantages of the generalized reservoir method were shown to be its relative simplicity and feasibility, whereas that of the hydraulic connection method was its detailed representation of underground flooding. Both the cumulative quantity of rainfall and rainfall intensity were shown to have important effects on underground inundation. The results of this study can help to improve urban stormwater forecasting and warning systems, and provide a theoretical basis for regional disaster prevention and reduction.
2023, 34(2): 218-226.
doi: 10.14042/j.cnki.32.1309.2023.02.006
Abstract:
Aiming at the complex calculation process and poor stability of vertical flow exchange in one-dimensional and two-dimensional coupled model for urban flood, an improved vertical flow exchange method is proposed based on the principle of node water balance. The nodes of one-dimensional model are divided into overloaded nodes and non-overloaded nodes. For overloaded nodes, the principle of node water balance is used to calculate the vertical exchange flow, and the vertical exchange flow calculation is integrated with the hydraulic calculation of one-dimensional model to realize simultaneously solving of node vertical exchange flow and pipe flow. For non-overloaded nodes, the variable head orifice outflow formula is used to calculate the vertical exchange flow, so that calculation of node backflow considering change of surface water depth is realized. Using the Infoworks ICM model as a comparison, simulation results of different cases are compared. Compare results show that the proposed method has a high degree of agreement with the simulation results of contrast model (Nash-Sutcliffe efficiency coefficients are larger than 0.8), and the proposed method has the ability to simulate vertical flow exchange process accurately and ensures water balance of the system. Therefore, the coupled model with improved vertical flow exchange method has significant application value for urban flood simulation.
Aiming at the complex calculation process and poor stability of vertical flow exchange in one-dimensional and two-dimensional coupled model for urban flood, an improved vertical flow exchange method is proposed based on the principle of node water balance. The nodes of one-dimensional model are divided into overloaded nodes and non-overloaded nodes. For overloaded nodes, the principle of node water balance is used to calculate the vertical exchange flow, and the vertical exchange flow calculation is integrated with the hydraulic calculation of one-dimensional model to realize simultaneously solving of node vertical exchange flow and pipe flow. For non-overloaded nodes, the variable head orifice outflow formula is used to calculate the vertical exchange flow, so that calculation of node backflow considering change of surface water depth is realized. Using the Infoworks ICM model as a comparison, simulation results of different cases are compared. Compare results show that the proposed method has a high degree of agreement with the simulation results of contrast model (Nash-Sutcliffe efficiency coefficients are larger than 0.8), and the proposed method has the ability to simulate vertical flow exchange process accurately and ensures water balance of the system. Therefore, the coupled model with improved vertical flow exchange method has significant application value for urban flood simulation.
2023, 34(2): 227-237.
doi: 10.14042/j.cnki.32.1309.2023.02.007
Abstract:
The Daqinghe River basin is the most prominent area of groundwater overdraft in the Haihe River basin.In order to solve the problem of groundwater overdraft, this study carried out the suitability evaluation of integrated groundwater recharge in mountainous and plain areas in the basin.Select the buried depth of groundwater level, permeability coefficient, distance from the main canal of the middle line of the South-to-North Water Transfer, distance from the reservoir, precipitation infiltration coefficient, effective water storage space, slope, and surface elevation to build the GIS-AHP decision model to obtain the zoning map of the suitability of the study area, and use numerical simulation to evaluate the effect of the replenishment.The study shows that the suitable areas for recharge are mainly distributed in the piedmont reaches of Juma River, Qinglong River, Tanghe River and Cihe River, accounting for 4.5% of the total assessed area; at the same time, according to the assessment results of the suitability of recharge, the refined water replenishment scheme for river sections can greatly slow down the decline rate of groundwater storage variables, and the recharge is the best.Therefore, the suitable assessment of groundwater recharge in the basin based on the combination of GIS and numerical simulation is helpful to greatly improve the utilization efficiency of water resources in the region and provide the optimal over-extraction control scheme.
The Daqinghe River basin is the most prominent area of groundwater overdraft in the Haihe River basin.In order to solve the problem of groundwater overdraft, this study carried out the suitability evaluation of integrated groundwater recharge in mountainous and plain areas in the basin.Select the buried depth of groundwater level, permeability coefficient, distance from the main canal of the middle line of the South-to-North Water Transfer, distance from the reservoir, precipitation infiltration coefficient, effective water storage space, slope, and surface elevation to build the GIS-AHP decision model to obtain the zoning map of the suitability of the study area, and use numerical simulation to evaluate the effect of the replenishment.The study shows that the suitable areas for recharge are mainly distributed in the piedmont reaches of Juma River, Qinglong River, Tanghe River and Cihe River, accounting for 4.5% of the total assessed area; at the same time, according to the assessment results of the suitability of recharge, the refined water replenishment scheme for river sections can greatly slow down the decline rate of groundwater storage variables, and the recharge is the best.Therefore, the suitable assessment of groundwater recharge in the basin based on the combination of GIS and numerical simulation is helpful to greatly improve the utilization efficiency of water resources in the region and provide the optimal over-extraction control scheme.
2023, 34(2): 238-249.
doi: 10.14042/j.cnki.32.1309.2023.02.008
Abstract:
To obtain a compromise between the short-term benefits of water resources utilization and the long-term benefits of sedimentation reduction in reservoirs constructed in a heavy sediment-laden river, it is of great significance to study the comprehensive benefits of sedimentation reduction and power generation by means of mathematical modelling.Fully incorporating the interaction between flow and sediment transport and bed deformation processes, a numerical model coupling flow-sediment transport and power generation is developed by integrating a 1-D morphodynamic module, a reservoir operation module and a power generation module.The proposed model was respectively calibrated and verified with the measured hydrological and electric data in the Sanmenxia Reservoir in 2019 and 2020, and moreover the influences of different hydrological regimes and operation schemes on sedimentation volume and power generation were analyzed.The results show that the calculated values of water level, discharge and sediment concentration were in good agreement with the measured values, and the relative error of power output was within 15%, so the model can be used to simulate the processes of both bed deformation and power generation in reservoirs reasonably well.The variations in the amounts of sedimentation volume and power generation can reach 129%—360% and 18%—52% respectively, compared with those under the condition of large water volumes and small sediment discharges.Lowering the initial pool level of the non-flood season can control the sedimentation in a non-flood season, and increasing the critical inflow discharge for sluicing in a flood season can improve the comprehensive benefits of sedimentation reduction and power generation.
To obtain a compromise between the short-term benefits of water resources utilization and the long-term benefits of sedimentation reduction in reservoirs constructed in a heavy sediment-laden river, it is of great significance to study the comprehensive benefits of sedimentation reduction and power generation by means of mathematical modelling.Fully incorporating the interaction between flow and sediment transport and bed deformation processes, a numerical model coupling flow-sediment transport and power generation is developed by integrating a 1-D morphodynamic module, a reservoir operation module and a power generation module.The proposed model was respectively calibrated and verified with the measured hydrological and electric data in the Sanmenxia Reservoir in 2019 and 2020, and moreover the influences of different hydrological regimes and operation schemes on sedimentation volume and power generation were analyzed.The results show that the calculated values of water level, discharge and sediment concentration were in good agreement with the measured values, and the relative error of power output was within 15%, so the model can be used to simulate the processes of both bed deformation and power generation in reservoirs reasonably well.The variations in the amounts of sedimentation volume and power generation can reach 129%—360% and 18%—52% respectively, compared with those under the condition of large water volumes and small sediment discharges.Lowering the initial pool level of the non-flood season can control the sedimentation in a non-flood season, and increasing the critical inflow discharge for sluicing in a flood season can improve the comprehensive benefits of sedimentation reduction and power generation.
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- 1Evolution and variation characteristics of the recorded runoff for the major rivers in China during 1956—2018
- 2Quantifying attribution of runoff change for major rivers in China
- 3Progress on disaster mechanism and risk assessment of urban flood/waterlogging disasters in China
- 4Cause analysis of the centennial trend and recent fluctuation of the Yellow River sediment load
- 5Progress in development and utilization of non-conventional water resources in China
- 6Application of Copula functions in hydrology and water resources: a state-of-the-art review