基于GIS的皖南地区暴雨洪涝灾害风险区划

目的]开展对不同重现期暴雨淹没深度模拟研究,分析皖南地区不同重现期下暴雨洪涝灾害淹没情况和不同承灾体的风险区划情况,为皖南地区防洪减灾工作提供科学依据。方法]文章采用算术平均值方法计算面雨量及雨型分布,通过广义极值分布函数拟合,得到拟合参数和不同重现期下日致洪面雨量,利用FloodArea模型计算暴雨淹没深度图谱。即利用皖南地区1961~2014年降水数据,结合人口、GDP及土地利用类型研究分析皖南地区暴雨洪涝灾害风险和区划。结果]皖南地区各子流域暴雨日分布特征及致洪面雨量有很大区别,牧龙河、黄湓河等流域致灾暴雨普遍偏强,漳河、青弋江等流域致灾暴雨普遍偏弱。暴雨洪涝灾害风险区划的一致性表现为各类承灾体风险等级均呈现10年一遇和20年一遇重现期较小,50年一遇重现期中等,100年一遇重现期较大的特点;区域性体现在对3种承灾体空间分布差异明显,其中人口分布集中,GDP分布相对分散,建筑用地情况和人口分布基本吻合,耕地面积比人口和GDP更广泛。结论]皖南地区暴雨洪涝灾害不同承灾体的风险区划呈现一致性和区域性特征,暴雨洪涝灾害不同重现期与人口密集区、经济发达地区、建筑用地、耕地附近的暴雨洪涝灾害风险等级呈现一致性特征。

RAINSTORM AND FLOOD RISK REGIONALIZATION IN SOUTHERN ANHUI PROVINCE BASED ON GIS

In this paper, the methods of general extreme value distribution and FloodArea model were used to calculate disaster area and flood depth caused by storm during different recurrence periods in southern Anhui province from 1961-2014,then obtained different disaster bearing body risk zoning map based on the data of type of land use, population distribution, and GDP distribution. The results indicated that the consistency characteristics of the risk regionalization of rainstorm and flood presented same disaster features, the 10-year and 20-year flooding frequency were small, the 50-year flooding frequency was medium, and 100-year flooding frequency was large.The regional characteristics showed that the population and construction land were in high risk level.It concluded that the risk zoning of hazard-affected bodies in southern Anhui showed a consistency and regional characteristics. The flooding frequency period showed a consistency with the disaster risk levels of populated area, the economic developed area, cultivated land, and construction lands.