基于InfoWorks ICM模型的北京市东城区海绵城市改造效果分析与研究

Analysis and research on the effects of the sponge city construction in Dongcheng District of Beijing based on InfoWorks ICM model

以北京市东城区为研究区,基于InfoWorks ICM模型开展海绵城市改造效果分析研究,通过2018年8月11日、12日的场次降雨实测流量过程、积水深度来验证模型的适用性,对研究区降雨重现期为1 a、3 a、5 a和10 a的管网排水能力评估发现,引起研究区内涝频发的主要原因有:研究区管网排水能力普遍偏低、不透水下垫面面积占比高、局部微地形低凹等因素。通过模型模拟发现,当研究区内的新建、改建项目按照《雨水控制与利用工程设计规范》(DB 11685-2013)中要求实施后,排水能力不足1年一遇管网长度比例减少12%,1年一遇至3年一遇、大于10年一遇管网长度比例提高了2%、10%。“2016.7.20”场次暴雨的内涝积水模拟结果显示,改造后内涝最大积水深度减小了0.31 m,积水范围减小了8.67 hm^(2),积水总量减少了3.22万m^(3)。

Taking Dongcheng District of Beijing as the research area,the effect of sponge city construction is analyzed and studied based on InfoWorks ICM model.The applicability of the model is verified by the measured rainfall flow process and ponding depth on August 11 and 12,2018.Through the evaluation of the drainage capacity of the pipe network with rainfall return periods of 1 a,3 a,5 a and 10 a,it is identified that the main reasons for the frequent occurrence of waterlogging in the study area are:the drainage capacity of the pipe network in the study area is generally low;The area of impervious underlying surface accounts for a high proportion;Local terrain is low and concave.Through model simulation,it is found that when the new construction and reconstruction projects in the study area are implemented in accordance with the requirements of code for design of rainwater control and utilization engineering(DB 11685-2013),the proportion of pipe network length with drainage capacity less than 1-year return period is reduced by 12%,and the proportion of pipe network length from 1-year return period to 3-year return period and greater than 10-year return period is increased by 2%and 10%.The waterlogging and ponding simulation results of the rainstorm of“2016.7.20”show that after the transformation,the maximum waterlogging depth is reduced by 0.31 m,the ponding range is reduced by 8.67 hm^(2),and the total ponding is reduced by 32200 m^(3).