针对城市内河网水系密集、开发强度高、点面源复杂、水污染严重的城市湖泊水环境问题，从流域水环境系统出发，建立了一套耦合“陆面单元-河网-湖泊”为一体的水环境模型，模拟分析实施各种水环境综合整治方案后的城市内湖泊水质改善状况，并将该方法应用于广东省惠州市金山湖流域。研究结果表明实施控源截污工程削减50%面源和95%点源负荷能够有效改善金山湖湖区水质状况，进一步通过6 m3/s的引水工程，湖区NH3-N和TP水质浓度基本上能够达到IV类水质治理目标。相较于单一的水质模型，该模型能够对水环境系统中的水文、水动力和污染物迁移扩散等主要过程进行模拟分析，有效反映点面源污染物负荷和水动力条件变化下的湖泊水质状况，为河湖连通条件下城市湖泊水环境治理工作提供技术支撑，推进整治城市黑臭水体，助力生态文明建设。

This study is aimed at the urban lake water environment problem in which the river network is complex and the development intensity is high. The serious water pollution problems in the urban lake, which caused by lots of point source pollution and non-point source pollution, are threatening the safety of aquatic ecosystems and human health. From the perspective of watershed water environment system, a water quality model coupled with “land surface-river network-lake” was established. The model was applied to Jinshan Lake watershed in Huizhou City, Guangdong Province to simulate the water quality of urban lakes under various water environment comprehensive remediation schemes, and to assess and analyze the improvement of urban water quality. By reducing 50% of non-point source pollutant load and 95% of point source pollutant load, the water quality of Jinshan lake can be effectively improved. Further, through 6m3/s water diversion project, the concentration of NH3-N and TP in the lake can basically achieve the goal of class IV water quality control. Compared with a single water quality model, the coupling model can simulate the main processes such as hydrology, hydrodynamics and pollutant migration and diffusion in urban lake water environment systems. The change of urban lake water quality under different point source pollutant load, non-point source pollutant load and hydrodynamic conditions is effectively reflected. By combining the distributed watershed non-point source pollution models, one-dimensional hydrodynamic water quality model of river network and two-dimensional hydrodynamic water quality model of lakes, the water quality model system provides technical support for water environment restoration of urban lakes under the impact of river network, and is expected to promote the treatment of urban black and odorous water body, and help the construction of ecological civilization.