城市湖泊在自身形态、功能和水循环特性上与天然湖泊有很大的差异，城市湖泊主要靠人工引水来满足生态环境需水，现有天然湖泊的生态环境需水计算方法不能完全适用于城市湖泊。根据满足城市湖泊生态服务功能的需水要求，以防洪控制、水质控制和景观水位控制为约束条件，建立了确定城市湖泊需要引水量和引水水质的计算模型。经郑州市郑东新区龙子湖生态环境需水实证分析，取得了实用性成果和结论。

The urban lakes have a great difference with the natural lakes in shape, function and water circulation. The urban lakes mainly depend on manual diversion for satisfying the water need of ecological environment. The calculation method of the ecological water demand of the natural lakes cannot be used in the urban lakes. For satisfying the ecological water requirement of service function of the urban lakes, this paper sets up a calculation model for determing the water demand quantity of the urban lakes and the quality of diversion water, and taking flood control, water quality and the water level of landscape as the constraint conditions. The practicable achievement is achieved by the analysis of the ecological water demand of Zhengdong New District in Zhengzhou City.