Hydrological Response and Ecological Flow Optimization in Water Diversion Area of Inter-basin Water Diversion Project

This article investigates the hydrological response and ecological flow in the diversion area from the Hanjiang River to the Weihe River. Quantifies the impact of the inter-basin diversion project on the hydro-ecological environment of the downstream river. MIKE BASIN is initially utilized in this research to create the multi-year reservoir operating model of Sanhekou Reservoir. Then Indicators of Hydrologic Alteration (IHA) and Range of Variability Approach (RVA) are used to evaluate the change degree of hydrological indicators. Secondly, set seven different ecological flow process schemes considering ecological demand and inter-annual wetness and dryness variability. Finally, evaluate the optimization scheme by Analytic Hierarchy Process (AHP). According to the hydrological response results, suggestions are put forward from the perspective of engineering and non-engineering. The results show that the simulation results of the MIKE BASIN have a high degree of fitting with the design results, which verifies the rationality of the model. Under the design scheme, the overall hydrological change of the river is 72.91% and the hydrological response of the river is high changed. Scheme 6 can reduce the overall hydrological change to (56.63%) moderate change under the premise of less impact on economic benefits, and scheme 6 is the optimal scheme. The research results not only guarantee the ecological function of the river but also provide guidance and reference significance for the actual operation of the reservoir.