Simulation study on the impact of ecological water replenishment on reservoir water environment based on Mike21——Taking Baiguishan reservoir as an example

Abstract

In recent years, ecological water replenishment has become the main means to improve the water environment of the reservoir. Considering the complexity of the water characteristics of the reservoir, it is very necessary to simulate the impact of water replenishment on the water environment. Based on the two-dimensional water environment mathematical model theory, the water environment model of Baiguishan Reservoir was constructed by Mike21. Under the conditions of 6 different ecological water replenishment scenarios, the evolution characteristics and improvement of the water environment of the reservoir were analyzed. Finally, the cloud model was used to comprehensively evaluate the results and compare them. Come up with the best ecological water replenishment plan. The results show that the strong convective diffusion phenomenon caused by the large flow of water replenishment makes the water quality show a cascade distribution, and the water quality improvement rate can reach up to 40.01%. Optimal; the water body with large flow replenishment has better fluidity and reoxygenation ability, which improves the self-purification ability of the water body. The comparison with the actual replenishment effect shows that the effect of large flow and short duration is better under the same replenishment amount. The quantitative analysis results of pollutants under different scenarios can provide a scientific basis for the construction of the South-to-North Water Diversion Project and the ecological restoration of the reservoir.