基于栅格的鄱阳湖生态经济区洪灾脆弱性评价

Flood Vulnerability Assessment of Poyang Lake Economical Ecological Zone at Raster Level

目前洪灾脆弱性研究主要是基于行政区划上的社会脆弱性评价,无法揭示评价单元内部脆弱性的空间分布。选取鄱阳湖生态经济区作为研究对象,根据人与环境系统的特点,选择影响洪灾脆弱性的15个变量,建立了基于栅格的洪灾脆弱性综合指数模型。结果表明,研究区域的洪灾脆弱性以中度脆弱为主,极度与高度脆弱区主要分布在人口密集的鄱阳湖东南与西南部的湖滨地区、主要河流的缓冲区以及土地利用类型为水田的区域。从脆弱性的3个要素(暴露度、敏感性和适应能力)的空间分布揭示了洪灾脆弱性空间分布形成的原因。基于栅格的评价结果,能够充分反映县市内部和行政边界处洪灾脆弱性的空间分布与变化情况。

Nowadays, researches on flood vulnerability assessment focus on social vulnerability to flood at ad- ministrative-division level, which can not present spatial distribution of vulnerability within assessing units and scaling effect of vulnerability. According to the features of human-environment system of Poyang Lake Economical Ecological Zone, fifteen indicators were selected to develop a composite index of flood vulnerabil- ity. The result indicated that the majority of the study area was moderately vulnerable to floods. High and ex- tremely vulnerable areas were located at the lakeshore area of the southeast and the southwest of Poyang Lake, the buffer area of main rivers and the paddy fields. We analyzed the spatial distribution of flood vulnerability from the distribution of exposure, sensitivity and adaptive ability. The study was to develop a method to identi- fy flood vulnerability at a grid level, which presented the spatial distribution of vulnerability within assessing units and at borders among units. It will supply policy makers with scientific grounds to establish multi-scale policy of flood protection.