城市社区水灾脆弱性评估及其风险防范研究

This project focuses on quantifying and reducing flood vulnerability at the scale of community. Because of its high flood risk, the city of Nanjing is selected as our study area. First of all, according to the theory of disaster system dynamics, the basic causes of flood vulnerability from natural environment and human system will be analyzed. That will help us to develop a conceptual model about flood vulnerability at the scale of community. Then, guided by the conceptual model, indicators for quantifying community vulnerability can be further identified and selected. In the second part of our project, the behavior and interaction between scales and in the scale will be studied. Based on which, a multiscale mode for quantifying vulnerability will be designed. The value of vulnerability will be divided into the one about potential loss and the other one about adaptation. So, vulnerability assessment can be done in one part of “from top to bottom” for evaluating the potential loss and the other part of “from bottom to top” for estimating the adaptation. In the multiscale mode, in order to quantify vulnerability, we will apply different methods such as spatial modeling, complex network analysis and public perception survey with diverse kinds of data, such as high-resolution remote sensing images, GIS data, statistical data,fieldwork data and disaster loss data. In the last part, we will propose a new form for vulnerability characterization based on risk perception and spatial aggregation.Then, the decision suggestion about integrative risk government to flood vulnerability will be studied and designed for community managers.

本项目以南京市为研究区，以社区为研究对象，首先依据灾害系统动力学原理，从自然环境与人文系统两方面入手，分析城市社区水灾脆弱性形成机理，架构“面向地区”与“面向单体”相结合的社区水灾脆弱性概念模型，并确定社区水灾脆弱性指标评估体系。进而探索水灾脆弱性在尺度间和尺度内的表现与相互作用机制，为开展多尺度评估奠定基础。在定量评估中，将指标分为弱聚合和强聚合两类，将脆弱性分为潜在损失和适应性两类，基于多源基础数据（高精度影像数据、地理信息数据、社会经济数据、野外实测数据、灾害数据等），结合运用空间建模、复杂网络理论、感知测度等方法创建“自上而下”的分解模式与“自下而上”聚合模式相结合的社区水灾脆弱性多尺度评估方法。同时，依据风险感知理论和空间聚合方法探索社区水灾脆弱性的多元表征模式。在此基础上，开展面向灾害管理者的综合风险防范决策支持研究。

本项目以南京市为研究区，以社区为研究对象，首先依据灾害系统动力学原理，从自然环境与人文系统两方面入手，从“系统”、“关注内容”、“致灾因子”和“时间参照”四个方面进行设定，厘清了脆弱性因子的类别，架构“面向地区”与“面向单体”相结合的社区水灾脆弱性概念模型，并确定社区水灾脆弱性指标评估体系。在定量评估中，本课题组创建了“自上而下”的分解模式与“自下而上”聚合模式相结合的社区水灾脆弱性双向评估方法。“自上而下”模式主要基于多源基础数据，结合运用空间建模、相似度方法，从“外部暴露性”、“内部暴露性”、“自然脆弱性”和“社会脆弱性”四个角度入手，进行水灾脆弱性的估算。“自下而上”模式从系统的视角进行考察，通过社区内个体的感知测度等方法，分析并估算了个体脆弱性和适应力。最终，“自上而下”和“自下而上”的两种评估模式都汇聚到社区这一本体上。基于上述研究成果，本课题组对社区水灾脆弱性作空间展示和分析。同时，选择“风险感知”、“自然脆弱性”和“社会脆弱性”三个关键属性进行社区综合风险的三维表征。根据研究结果和表征特点，并基于“风险阶梯”设计思想，确定社区水灾综合风险的判断标准和评定规则，设立了“红橙黄绿蓝”五色预警等级，对每一等级进行了详细的针对性防范措施设计。最后，又对社区综合风险防范组织体系、应急物资准备和居民风险意识教育进行了设计。