关键词: 纳污能力, 污染物扩散, 二维水质模型, 水功能区, 三峡水库

Abstract: The hydrological regime and water eco-environmental conditions in the middle reach of the Yangtze River have changed since the operation of Three Gorges Reservoir and the upstream cascade reservoirs. Taking Hanyang drinking water source and industrial water areas in Wuhan reach as the research objects, the river two-dimensional water quality model and the plane two-dimensional hydrodynamic water quality model are used to study the pollution bearing capacity of water function zones and diffusion law of COD and NH3-N. The results show that in the dry season, hydrological condition and the lateral width of water function zones have a great influence on water pollution bearing capacity. Since the operation of Three Gorges Reservoir, the pollution bearing capacity of COD and NH3-N in 50 m lateral width of the river reach are 17850, 1233 t / a, which increased in some extent, and the diffusion scope of pollutants in the dry season has been reduced. The study results can provide scientific basis for the total amount control of river pollution, the management of sewage outfall and water environment protection.

Key words: pollution bearing capacity, pollutant diffusion, two-dimensional water quality model, water function zone, Three Gorges Reservoir