山区镇域山洪灾害孕灾环境分区研究

Research on Torrent Disaster Development Environment Partition in Mountainous Town-region

以重庆市巴南区接龙镇为研究范围,在分析山洪灾害孕灾因子基础上,选取地形坡度、地形起伏度、年均降水量、植被覆盖率、路网密度、居民点密度、历史灾害点密度共7个指标,构建山洪灾害孕灾环境分区指标体系,利用层次分析法确定各指标权重,采用综合指数法建立山洪灾害孕灾环境评价综合模型;利用ArcGIS软件,以100 m×100 m网格尺寸为单位精细获取研究区各评价指标数据,计算得到各网格孕灾环境综合指数值,并根据该值进行镇域山洪灾害孕灾环境等级划分;结果表明:研究区山洪灾害孕灾综合指数值在15-67之间,孕灾分区主要集中于中易发区,其中中易发区117.21 km2,占总面积的64.21%,低易发区61.70 km2,占33.81%,高易发区3.62 km2,占1.98%。

Taking Jielong Town,Banan District of Chongqing,as research area,on the basis of the analysis of torrent disaster development factors,this paper selects such seven indicators as topographical slope,topographical degree of ups and downs,average annual rainfall,vegetation coverage,road network density,residential density and historic disaster point density to construct the index system of torrent disaster development environment partition, uses analytic hierarchy process to determine the weight of each indicator,uses comprehensive index method to construct comprehensive evaluation model of torrent disaster development environment,uses ArcGIS software and takes 100mx100m grid size as the unit to accurately obtain each evaluation indicator data in the studied region,uses calculation to receive the comprehensive indicator value of each grid disaster development environment,and makes division of town-region torrent disaster development environment according to the scores of the comprehensive indicator value. The results show that the comprehensive index value of torrent disaster development in the studied region is between 15 and 67,that disaster development partition is mainly centralized at medium easily-happening area,that medium easily-happening area covers 117. 21 km2,accounting for 64. 21 percent of the total area,that low easily-happening area covers 61. 70 km2,accounting for 33. 81 percent,and that high easily-happening area covers 3. 62 km2,accounting for 1. 98 percent.