北京市下凹式立交桥区低影响开发效果模拟

Simulation of low impact development effect in Beijing underpass area

北京市下凹式立交桥等低洼区的内涝治理是防洪减灾工作的重点与难点。以北京市北三环安华桥桥区为研究对象,构建桥区一维雨洪模型,利用反映北京市不同雨强、由暴雨强度公式与芝加哥雨型公式推求得到的不同重现期设计暴雨,模拟低影响开发(LID)措施实施前后桥区的积水情况,从积水开始时间、积水持续时间以及积水深度3个方面分析了LID措施的洪涝防控效果。结果表明:LID措施对下凹式立交桥区内涝具有一定的防控作用,但随着暴雨重现期的显著增加,LID措施的洪涝防控效果明显减弱。研究成果可为海绵城市建设提供参考。

The treatment of waterlogging in low-lying areas such as underpass is the key and difficult point of flood control and disaster reduction work in Beijing. Taking the Anhua Bridge area on the third-ring road in Beijing as an example,the one-dimensional rain flood model of the bridge area is constructed and used to simulate the waterlogging level in the bridge area before and after the implementation of LID measures in the context of different recurrence design rainstorms derived from the rainstorm intensity formula and Chicago rain formula which could reflect the different rain intensity in Beijing. The waterlogging prevention and control effect of LID measures are analyzed from the aspects of flood start time,duration and depth. The results show that the LID measures have a certain control effect on the waterlogging in the underpass area,but with the significant increase of the rainstorm recurrence period,the flood control effect of the LID measures is obviously weakened. The research results can provide reference for sponge city construction.