基于GIS和AHP方法的喀斯特地区泥石流危险性评价

Risk Assessment of Debris Flow in Karst Area Based on GIS and AHP

泥石流主要发生在山区,给人们的生活、生产、生存带来严重危害。以贵州省关岭县为例,从地形地貌、地质构造、水文气候、人类活动4个方面选取了高程、地层岩性、年降水量、人口密度等9个评价指标,利用层次分析法确定了各指标因子对泥石流的影响权重;基于GIS技术构建研究区泥石流危险评价模型,对研究区泥石流灾害的危险性进行分级,评价泥石流危险性原因,绘制危险性分布图。研究结果表明:泥石流极高危险区和高危险性区主要分布在研究区中部和北部区域,面积达到研究区总面积的30%;危险性最小区主要分布在研究区西北、东南等区域,占研究区面积的11.47%;选取的9个评价指标都是影响泥石流发生的重要因子。通过研究将理论分析指导实际应用,对政府有效进行关岭县泥石流灾害的预警及防治对策制订提供参考,为减灾防灾奠定了坚实的基础。

Debris flow mainly occurred in the mountains,causing serious harm to people's life,production and survival.In this paper,9 evaluation indexes of elevation,stratigraphic lithology,annual precipitation and population density were selected from four aspects: topography,geological structure,hydrological climate and human activity in Guanling county of Guizhou Province.This paper determined the weight of each index factor by analytic hierarchy process.Based on GIS technology,the risk assessment model of debris flow in the study area was established.The risk of debris flow disaster in the study area was graded,the risk of debris flow was evaluated and the risk distribution map was drawn.The debris flow areas with extremely high risk and high risk were mainly distributed in the middle and northern regions,reached 30% of the study area.The most dangerous areas were mainly distributed in the northwest and southeast regions of the study area,accounting for 11.47%.The 9 evaluation indexes were the important factors affecting the occurrence of debris flow.Through the research,the author would provide a reference for the government to effectively carry out the early warning and prevention countermeasures of debris flow disaster in Guanling,and lay a foundation for disaster prevention and control.