基于层次分析法与GIS相结合的岩溶塌陷地质灾害易发性分区评估——以云南省师宗县为例

Geo-Hazard Susceptibility Zoning Evaluation of Karst Collapse Based on the Combination of AHP and GIS:A Case Study of Shizong,Yunnan

以岩溶地貌发育的云南省师宗县作为研究实例,通过层次分析法确定岩溶塌陷评估因子及其权重值,并划分岩溶塌陷评估因子的等级。在此基础上,利用GIS空间分析技术对岩溶塌陷空间数据进行处理和分析,按地质灾害综合危险性指数R值将研究区域划分为三大地质灾害易发程度不同的区域,并通过实例验证分析地质灾害综合危险性指数R值求取的可行性,实现了基于层次分析法与GIS技术相结合的云南省师宗县岩溶塌陷地质灾害易发性分区和评估。结果显示:师宗县岩溶塌陷高易发区(4≤R≤5)集中分布于研究区域的北部和中部,占总面积的39.22%;中易发区(2<R<4)集中分布于北部和南部,占34.89%;低易发区(1≤R≤2)集中分布于南侧,占25.89%。总体上,该区域岩溶发育程度为强发育;岩溶塌陷地质灾害易发程度在空间分布上具有明显的地带差异性。

In this paper, Shizong County of Yunnan Province is taken as an example to evaluate the geo-hazard susceptibility zones of Karst coUapes. AHP is used to determine the evaluation factors of karst collapses and their weights, and the evaluation factors are graded. Then the regional geological environmental conditions are analyzed. On that basis, by using the GIS spatial analysis technology, the spatial data of karst collapses are processed and analyzed. The studied area can be classified into three types of zones with different geological hazard susceptibility according to the geo-hazard comprehensive risk index R value. They are the high susceptibility zones （ 4≤R≤5 ）, the medium susceptibility zones （ 2〈R〈4 ）, and the low susceptibility zones（1≤R≤2）. The feasibility of geo-hazard comprehensive risk index R value is checked with its application to practice. The result shows that the high susceptibility zones are mainly distributed in the northern and central parts of the county, accounting for 39.22% of the total area; the medium susceptibility zones are mainly distributed in the northern and southern parts, accounting for 34.89% of the total; and the low susceptibility zones are mainly distributed in the south, accounting for 34.89%. Generally, the karst landscape development degree in Shizong County is very high, and geographic hazard susceptibility of karst collapses shows obviously zonality differentiation in spatial distribution.