Joint Regulation Of Surface Water And Groundwater Considering Flood Resources

Due to the combination of natural conditions and rapid economic and social development,it has caused a series of water resource and water environment problems,such as shortage of water resources,deterioration of the water environment,and excessive exploitation of groundwater.These problems have gradually become an important constraint restricting the sustainable development of my country's economy and society.In the northern regions of China,the time distribution of water resources is uneven,and about 70%of rainfall and runoff are concentrated in the flood season.How to improve the utilization rate of rain and flood resources by using various engineering measures and non-engineering measures is a very urgent practical demand for the severely water-scarce northern regions.At the same time,over-exploitation of groundwater resources in some areas has produced large-scale groundwater funnels.So that how to use groundwater resources rationally while gradually repairing the groundwater system is also very urgent.Through the control and application of existing water conservancy projects,it is possible to increase the utilization rate of flood resources and improve the circulation conditions of groundwater.Based on the background of the Taizi River Basin in Liaoning Province,this paper aims at the problems that exist in the actual operation of the Shenwo Reservoir and the fact that the long-term unreasonable development of the groundwater downstream of the reservoir has produced a large-scale dropping funnel,Study through the dynamic control of the flood control water level of the Shenwo Reservoir during the flood season to improve the reservoir's water storage capacity.And through reasonable adjustment of the discharge flow,increase the river's recharge of groundwater,repair the groundwater system of the riverside,and jointly control the Shenwo reservoir and its downstream groundwater system to achieve the goal of optimizing the use of flood resources.Therefore,this article designs the following main research contents:(1)Analyzing the control and utilization of existing water conservancy projects in the Taizi River Basin and the current situation of groundwater resources utilization in the downstream of the reservoir deeply,and summarize the main problems that still exist during the period,and put forward the main problems that this article intends to solve.(2)The forecast product of the ECMWF Rainfall Forecast Center was selected as the input for the dynamic control of the flood limit water level of the Shenwo Reservoir to quantitatively analyze its availability.Taking the annual flood season from May to September in the Taizi River Basin as the research period from 2008 to 2017,the availability of 120h rainfall forecast information in the Taizi River Basin was analyzed.The results show that the forecast information released by ECMWF with a forecast period of 120 hours has reached a certain accuracy,and can be applied to the flood control of Shenwo Reservoir.(3)Based on the characteristics of the Shenwo Reservoir and the existing research results,the improved pre-discharge capacity constraint method was selected to calculate and determine the dynamic control area of the Shenwo Reservoir during the flood season.After calculation,the dynamic control domain of the Shenwo Reservoir during the main flood season is[86.20m,88.83m],and on this basis,a dynamic control scheme for the pre-storage and pre-discharge of the reservoir was formulated.To verify the practicability of this achievement,taking the sub-flood of“20120803”in the Taizi River Basin as an example,through comparison with the conventional dispatching method of Shenwo Reservoir,the following conclusions were drawn:Taking[86.20m,88.83m]as the dynamic control domain,according to the pre-storage and pre-discharge scheduling method of 120h rainfall forecast information,the reservoir can increase flood resources by 508 million m~3 and the amount of river water supply to groundwater increased by about 0.01 billion m~3 without reducing the flood control risk of the reservoir.This not only improves the beneficial water storage benefits of the reservoir,but also lays a foundation for the rivers downstream of the reservoir to increase groundwater recharge.(4)By calculating the amount of surface water rechargeable groundwater resources and storage capacity of groundwater storage space in the Taizi River Basin,the actual storage capacity of the groundwater reservoir in the Taizi River Basin was determined.Aiming at the goal of maximum utilization of water resources and minimum amount of abandoned water after joint regulation of surface water and groundwater,a joint regulation model of surface water and groundwater has been established,and by virtue of its simulation operation,a feasible scheme for joint regulation and control has been determined.Finally,the feasibility plan set is optimized to determine the optimal plan for joint regulation of surface reservoirs and groundwater reservoirs.