基于GIS和SWMM的城市雨洪模型构建与业务化

Construction and Operation of Urban Storm Flood Model based on GIS and SWMM

近年城市化进程加快,极端天气频繁出现,各大城市都出现过严重的内涝情况,严重危害人民群众的财产和人身安全。暴雨洪水管理模型(storm water management model,SWMM)等常用的城市雨洪径流模型已在城市内涝研究中广泛应用且效果显著。但构建SWMM工程文件所需的数据处理相对烦琐且对大多数模型来说,模型的输入和输出数据不直观,使用极不便。针对这一现状,研究如何快速构建城市雨洪模型并实现业务化意义重大。以成都市双流区东升街道为例,基于双流行政区划边界图层、排水(雨水)管网分布图、气象站点实况监测、数字高程模型(digital elevation model,DEM)和土地利用分类等多源数据,利用地理信息系统(geographic information system,GIS)技术,数字化并概化双流区的地下管网,利用水文分析法和泰森多边形法划分东升街道子汇水区,使用表面分析方法和分区统计方法计算处理各子汇水区的不透水占比、平均百分比坡度;利用GIS软件开发技术实现子汇水区特征宽度的求取;最后实现成都市双流区东升街道雨洪模型的程序化构建、自动化运行和结果可视化等一系列业务化研发,并利用历史内涝个例数据对构建的东升街道雨洪模型进行模拟对比验证,结果显示溢流节点与记录发生的汛情一致,效果良好;相应成果也应用到了双流城市内涝预警业务中。

In recent years,the process of urbanization has accelerated,extreme weather has occurred frequently,and serious waterlogging has occurred in major cities,which canseriously endanger the property and personal safety of the people.SWMM(storm water management model)and other commonly used urban storm flood runoff models have been widely used in urban waterlogging research and have achieved some remarkable results.However,the data processing required to build the SWMM project file is relatively cumbersome and for most model users,the input and output data of the model are not intuitive and extremely inconvenient to use;In view of this situation,it is of great significance to study how to quickly build urban storm flood model and realize its commercialization.Taking Dongsheng Street,Shuangliu District,Chengdu as an example,the author digitised and generalized the underground pipe network in Shuangliu District using GIS(geographic information system)technology based on multi-source data such as boundary layer of Shuangliu administrative division,distribution map of drainage(rainwater)pipe network,actual monitoring of meteorological stations,DEM(digital elevation model)and land use classification,the sub-catchment area of Dongsheng Street is divided by hydrological analysis method and Tyson polygon method,and the impervious proportion and average percentage slope of each sub-catchment area are calculated and processed by surface analysis method and zoning statistical method;GIS soft-ware development technology is used to obtain the characteristic width of sub-catchment area.Finally,a series of operational research and development of the rain and flood model of Dongsheng Street in Shuangliu District,Chengdu,including the programmed construction,automatic operation and result visualization,were realized.The simulation and comparison of the rain and flood model of Dongsheng Street were carried out using the historical waterlogging case data.The results showed that the overflow node was consistent with the flood record,which means the performance of this model is good.The corresponding results have also been applied to the urban waterlogging early warning business in Shuangliu.