城市浅水湖泊雨水溢流总磷输运的数值模拟

从三维对流-扩散-反应方程出发，根据雨水箱涵溢流入湖总磷形态特性，推导雨水溢流进入城市浅水湖泊后二维总磷的输运方程，并与浅水流动方程结合，建立城市浅水湖泊平面二维水流-水质总磷的数学模型.模型通过深圳荔枝湖实测资料验证，计算结果较好.用此模型计算设计降雨强度28 mm/h历时1 h情况下，雨水径流通过箱涵溢流进入荔枝湖和湖水混合后总磷输运情况，分析了入湖雨水总磷归趋.结果表明，溢流入湖TP通量为15.385 kg，其中62.3%掺混在水体中，28.1%沉积到表层底泥；污染后的湖水通过水污染治理工程连续运行3.0 d可将荔枝湖TP恢复到雨前初始浓度水平.

Numerical Simulation of TP Transport After Overflow of Rainwater into Urban Lake

Based on the three-dimensional advection-diffusion-reflection equation, a two-dimensional TP transport equation was deduced to simulate TP distribution and transport after overflow rainwater into urban lake from storm sewer system during rainstorm. The model has a good agreement with a group of monitor data at Lake Lichee in Shenzhen, China. The model was applied to compute the scenario in Lake Lichee under the design rainstorm, and analyse the fate of TP. It shows that TP flux into lake is 15.385kg under city storm intensity of 28 mm/h, in which 62.3% of flux goes into water in lake and 28.1% TP flux settles surface sediment. It would take 3.0 days for the integrated treatment project operation to recover TP to the level before the rain.