Simulation Study on the Impact of South–North Water Transfer Central Line Recharge on the Water Environment of Bai River

To effectively improve the water quality of Bai River, this paper proposes use ecological replenishment South–North Water Transfer as a measure for integrated allocation resources, addressing impact complex topography, climate, and human disturbances on river’s environment. This can alleviate problem shortage significantly enhance River’s Using MIKE21 coupled hydrodynamic water-quality model, analyzes recharge river hydrodynamics simulates evolution various indicators, including dissolved oxygen (DO), permanganate index (CODMn), chemical demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP) under different scenarios. The aim is to investigate mechanism results show that most significant improvement in achieved when flow 2Q duration 1/2T (scenario 1), with improving from grade IV standard III standard, COD TP indicators II largest rate 94.67% seen DO, best DO reduction 66.67% indicators. Overall, quality, scenario 1 being effective approach. study may provide theoretical technical support future management environments.