前期影响雨量与雨水口过水能力对城市内涝影响研究

A study on the impact of early rainfall affecting and rainfall outlet capacity on urban waterlogging

为了研究雨水口过水能力与前期影响雨量对基于SWMM(Storm Water Management Model)的城市雨洪模型的影响,采用SWMM模拟技术进行城市雨洪模型精度改进研究。以柳州中心城区为例,构建城市雨洪模型并对现状进行评估,构建改进模型来评估雨水口过水能力与前期影响雨量对模型的影响。结果表明,改进后的模型更加符合实际测量值,其中峰值时间比原模型推后15 min,与实际相差15 min,峰值水位为3.18 m,比原模型减小了7%,更加接近实测值,总溢流量相较于原模型减少了16%,且前期影响雨量对重现期2 a、5 a情境有显著影响,雨水口过水能力对重现期5 a、10 a、20 a、50 a以及100 a情景都有显著影响,且影响随降雨强度的增大而变大。改进后的模型更加符合城市实际的内涝情况。

In order to study the impact of the storm water flow capacity and the previous impact rainfall on the urban storm water model based on SWMM(Storm Water Management Model), the SWMM simulation technology was used to improve the accuracy of urban stormwater model. Taking the central city of Liuzhou as an example, construct a model of urban rain and flood status and evaluate the status quo, and build an improved model to evaluate the influence of the rainwater outlet capacity and the previous impact rainfall on the model. The result shows that the optimized model is more in line with the actual measured value. The peak time is 15 min later than the original model, and the difference is 15 min from the actual. The peak water level is 3.18 m, which is 7% less than the original model, and is closer to the actual measured value. Compared with the original model, the overflow rate has been reduced by 16%, and the previous impact rainfall has a significant impact on the scenarios of 2 a, 5 a, and the flow capacity of the gully has a significant effect on the scenarios of 5 a, 10 a, 20 a, 50 a and 100 a, and the impacts increase with the increase in rainfall intensity. The improved model is more in line with the actual waterlogging situation in the city.