基于1D/2D耦合模型的排水系统内涝重现期校核

Check of Waterlogging Return Period of Drainage System Based on 1D/2D Coupled Model

耦合一维(1D)管网/二维(2D)地表漫流模型可以准确描述城市地区的暴雨积水过程,特别是超设计标准暴雨造成的城市内涝的演进全过程。以合肥市杏花排水系统为例,构建1D/2D耦合模型,通过实测数据完成模型的率定验证,在50年一遇的极端暴雨条件下,模拟杏花系统的内涝演进。结果表明,该排水系统内地形起伏较大,道路调蓄涝水的能力差,且不能配合市政排水系统行泄涝水,在极端降雨条件下形成了严重的局部涝灾。本研究为根据内涝设计重现期校核城镇排水系统排除积水能力规定的实施提供了参考。

Coupling one-dimensional pipe flow with two-dimensional surface flow hydraulic model was capable of simulating rainfall-runoff process and draining process, especially flood propagation in ur- ban areas due to overflow of sewer system. A coupled 1D/2D model was developed for Xinghua Catch- ment in Hefei City and calibrated with historical records. It was applied to check floodwater drainage abil- ity for the catchment under a 50-year return period heavy storm. The results showed that the surface gra- dient of the catchment was high, the detention effect of roads in the catchment was poor, and most of floodwater ran downhill, which leaded to heavy flood in depression areas. This paper provides a reference for check of flooding frequency of urban drainage system.