基于情景模拟与多源数据的城市内涝风险评估

Urban Waterlogging Risk Assessment Based on Scenario Simulation and Multi-source Data

以珠海市香洲城区为例,构建基于InfoWorks ICM的城市雨洪模型,采用HR阈值法量化2、10、50年三种重现期暴雨情景下区域危险性,基于百度人口密度热力图、夜间灯光遥感等多源数据获取脆弱性指标,结合层次分析法和熵权法量化脆弱性,对三种设计暴雨情景下的研究区内涝风险进行评估和区划,并绘制相应的高风险重现期区划图。结果表明,通过百度热力图等非传统数据源能够获取得到空间分辨率分别为4、130m的人口密度和GDP密度等精准合理的指标数据,可改善传统数据的空间分布粗糙性和时间滞后性;危险性和风险高值区主要分布在易涝城市区域,而脆弱性高值区主要分布在人口和经济密集区;随着暴雨重现期增加,区域风险逐渐增大,其中极高风险区面积增长率最高。高风险重现期区划图能够迅速识别不同暴雨情景下的高风险区域,可为防灾减灾工作的高效响应提供理论指导与技术支撑。

Xiangzhou district of Zhuhai City was selected as the research region.An urban rainfall-runoff model was constructed based on InfoWorks ICM to quantify the regional hazard under rainstorm return periods of 2 a,10 aand 50 a,respectively based on the HR threshold method.Vulnerability index data was obtained by multi-source data such as Baidu heat map and night light remote sensing.Then the weights of all vulnerability indices were quantified through combination of analytic hierarchy process and entropy weight method.Finally,the waterlogging risk map of the research region under the three design rainstorm scenarios and the corresponding high-risk return period zoning map were drawn.The results show that the multi-source data used in this study could obtain accurate and reasonable index data such as population density and GDP density with the spatial resolution of 4 mand 130 m,respectively,which could improve spatial precision and timeliness of the traditional data.Areas with relatively higher hazard and risk values were mainly located in the urban areas that were prone to waterlogging,and areas with relatively higher vulnerability values were mainly distributed in the areas that were dense in both population and economy.As the rainstorm return period increased,the regional risk became higher,and areas with very high risk had the highest growth rate.Moreover,the high-risk return period zoning map could be utilized to quickly identify high risk areas under different rainstorm scenarios,which could provide efficient guidance for disaster prevention and mitigation.