Study On River Health Evaluation And Optimal Allocation Of Water Resources In Shaying River Basin

The economic and social development in the Shaying River Basin has been rapid,and the influences of human activities have become more and more serious on the river system,therefore,a series of water problems occur,such as water pollution incidents,water ecology and environment deterioration,contradiction of water resources supply and demand,which have seriously affected the health status of rivers and the economic and social development in the Shaying River Basin.River health assessments can fully assess the state of river ecosystems and contribute to the management of rivers and restoration of good ecosystems.Optimizing the allocation of river basin water resources based on river health can not only promote the restoration and maintenance of river ecosystems,but also improve the efficiency of water resources utilization,ease water conflicts,and promote the balance between water supply and demand.It is effective in promoting the economic development and ecological restoration of river basins.Therefore,it is of great significance to improve the level of river health status,strengthen research on the optimal allocation of water resources,and promote the sound maintenance of the ecological environment of the river basin,sustainable economic and social development.This paper systematically summarizes the research status and existing problems in the optimization of river health and water resources allocation at home and abroad.Based on a the comprehensive analysis of the concept and connotation o f river health about gated rivers,the river health evaluation of the typical section,prediction of water demand and optimal allocation of water resources was conducted in Shaying River.The main contents and research results of the paper are as follows:(1)Health evaluation of Shaying river.The concept and connotation of river health for gated rivers were proposed,the theoretical framework and evaluation index system for river health assessment were established,the evaluation criteria and weights is determined.Seven cross-sections from upstream to downstream of the mainstream of Shaying River were selected as objects to calculate the RHI,getting the conclusion that the Shaying River is between sub-healthy and pathological.(2)Analysis of water supply and demand in administrative regions of Shaying River Basin.Based on the results of river health assessment,the minimum ecological flow,self-purification ecological flow,and appropriate ecological flow of five typical sections of the Shaying River were calculated using the Tennant method,hydraulic radius method and 7Q10 method.The maximum value of ecological water demand,self-purification ecological water demand,and appropriate ecological water demand during the flood and no n-flood seasons are taken as the ecological environment water demand within the river course that meets the needs of river health during this period.(3)Optimal allocation of water resources for river health in Shaying River Basin.Water resources optimizatio n allocation models for river health were developed with water resources optimization constraints,ecological water demand constraints,water quality constraints,and policy constraints.From the perspective of improving the health of the river,proposals combining the water demand side and the water supply side are proposed,and a multi-project optimization method is used to calculate the water distribution plan which is most conducive to the objective function.Based on this,optimize the allocation of water resources in each planning year in the basin,and put forward suggestions for the rational development and utilization of water resources in the Shaying River Basin.