基于水力模型的城市大型调蓄湖泊退水时间测算方法

调蓄湖泊在城市内涝防治中发挥着重要作用。当城市遭遇多场长历时强降雨时，若调蓄湖泊未及时腾空库容而漫溢，易引发系统性内涝灾害。为评估调蓄湖泊应对多场长历时强降雨时的防灾韧性水平，结合武汉市实际，提出了湖泊退水时间评价指标。以武汉市最大的3个湖泊水系为例，基于构建的湖泊水系水动力模型，模拟了100 a一遇不同超长历时设计降雨下的重点湖泊水位变化。结果表明：遭遇1 d设计降雨时，汤逊湖、东湖模拟最高洪水位均未超过控制最高水位，但退水时间较长，分别达到9 d、3 d+6 h；退水期间，再次遭遇强降雨时，存在较大内涝风险。该研究可为平原河网地区排涝标准的制定及排涝设施规模的设计提供参考。

Method of Calculating Time of Water Retreat in Urban Large Storage Lakes Based on Hydraulic Model

Storage lakes play an important role in the urban waterlogging prevention and control. A city is easy to suffer the systematic waterlogging disaster when encountering the multi-field long duration heavy rain if the storage lakes have not enough time to vacate the storage capacity and overflow. To evaluate the resilience level of urban storage lakes when encountering a continuous multi-field heavy rain, combined with the reality of Wuhan City, the evaluation index of the lake water-retreat time is proposed. Taking the three largest river systems in Wuhan as examples, and based on the built hydrodynamic model of lake water system, the water level changes of main lake under the 100 a different ultra-long duration design rainfalls are simulated. The results show that the simulated peak levels of flood water of Tangxun Lake and Dong Lake are both lower than the maximum control water levels during the 1 d design rainfall, but the water retreat takes long time by 9 d and 3 d+6 h respectively. During the water retreat period, there is a greater risk of waterlogging when heavy rainfall occurs again. The study can provide a reference for the formulation of waterlogging drainage standards and the scale design of waterlogging drainage facilities in the river network region of the plain.