基于水力排水模型的宁波海绵试点区内涝风险评估

Assessment of Urban Waterlogging Risk in Ningbo Sponge City Pilot Area Based on Hydraulic Drainage Model

随着城市化进程的不断加快,城市内涝灾害频发,利用水力排水系统模型对城市内涝风险进行评估已被广泛应用。针对平原河网城市内涝频发的现象,以宁波海绵城市试点区为例,基于InfoWorks ICM模型构建排水系统模型,模拟短历时不同重现期设计降雨(5、10、20、50 a)和长历时不同重现期设计降雨(10、50 a)下试点区内涝风险情况。结果表明,随着降雨强度的增加,风险区面积呈递增趋势,短历时设计降雨模拟显示中风险区的平均增长率约为21%,低、高风险区面积平均增长率约10%;50年一遇长历时设计降雨模拟显示试点区内涝风险等级分布以中、高风险为主,总占比约为91%,高风险区占比约51%。

With the acceleration of urbanization, the urban waterlogging disasters occur frequently.The hydraulic drainage model has been widely used to evaluate the risk of urban waterlogging.In view of the frequent occurrence of waterlogging in the plain water network cities,a drainage system model based on the InfoWorks ICM was established in the pilot area of the Ningbo sponge city to simulate the waterlogging risk under short duration design rainfall( 5-year,10-year,20-year,50-year) and long duration design rainfall( 10-year,50-year).The results showed that the risk area increased with the increase of rainfall intensity.The simulation results of short-duration design rainfall showed that the average growth rate of middle-risk areas was about 21%,while those of low and high risk areas were about 10%.According to the simulation results of the long duration design 50-year repetition period of rainfall,the distribution of waterlogging risk in the pilot area was mainly medium and high risk,accounting for about 91% in total,and 51% in the high risk area.