低影响开发系统对西南红层丘陵地区雨洪调控效果的模拟研究

为探究低影响开发系统(LID)对西南红层丘陵地区的雨洪调控效果,以中国遂宁市河东新区湿地公园示范区为研究对象,构建暴雨洪水管理模型(SWMM),根据遂宁市河东新区海绵城市建设相关规划,结合研究区下垫面特征,模拟不同降雨重现期(2、5、10、20年一遇)降水情景下低影响开发(LID)措施的地表径流过程和下渗过程,以评估海绵城市建设的防洪减涝效果。结果表明:在低降雨重现期(2年一遇和5年一遇)情况下,LID措施对地表径流的控制率分别达到78%和45%,洪峰的推迟现象不明显,在高重现期(20年一遇和50年一遇)情况下,地表径流控制率仅为2%和1%,洪峰的推迟时间分别为2、2.5 h,表明LID措施对城市雨洪控制有一定的效果,且随着降雨重现期的增加,LID措施对城市雨洪的控制效果逐渐减弱。研究结果为中国西南地区海绵城市建设及后期运营提供了理论依据。

Simulation study on the effect of low-impact development system on rainwater control in red bed hills in southwest China

In order to explore the effect of low-impact development system (LID) on rain and flood control in red hilly area in southwest China, this article took wetland park demonstration area of hedong new area, suining city, China as the research object. To evaluate the flood control and waterlogging reduction effect of sponge city construction, the storm flood management model (SWMM) was built and the surface runoff process and infiltration process of low impact development (LID) measures under different rainfall recurrence periods (2, 5, 10, 20 years) were simulated according to the construction plan of sponge city and the characteristics of the underlying surface of the study area. The results show that LID measures can control 78% and 45% of surface runoff flood in the case of low rainfall recurrence period (1 in 2 years and 1 in 5 years), However the delay phenomenon of flood peak was not obvious. In the case of high recurrence period (1 in 20 years and 1 in 50 years), the surface runoff control rate was only 2% and 1%, the delay time of flood peak is up to 2h and 2.5h. It is concluded that LID measures have a certain effect on urban rain flood control. As the recurrence period of rainfall increased, the control effect of LID measures on urban rain flood weakens. This study provides a theoretical basis for the construction and later operation of sponge cities in southwest China.