西南山区县域单元的地质灾害风险评价——以怒江流域泸水市为例

Geohazard risk assessment about county units in southwest mountainous areas of China:Take Lushui County of Nujiang river basin as an example

西南山区作为中国西部地区的高山峡谷区域,区内地质灾害十分发育,具有人口、房屋多集中于斜坡坡脚分布的特点,亟需寻找一套新的易损性评价方法,针对该区域进行有效合理的风险性评价。文中选取具有典型西部山区特征的泸水市,利用地质灾害基础数据,基于GIS平台和逻辑回归理论,对模型进行评估、多元共线性诊断、拟合度检验,建立地质灾害危险性评价模型,同时考虑承灾体可能遭受的破坏状态和类型,构建了不同类型承灾体的易损性指标分级赋值表,首次提出了针对西南山区人口、房屋等承灾体分布特征的易损性评价方法,综合评价地质灾害危险性、易损性及风险性。结果表明:泸水县城北部为地质灾害极高风险区和高风险区,县城及周边大部分区域为中风险区和低风险区,与野外调查评价结果基本一致。提出的风险评估方法能有效反应县域范围内地质灾害的风险现状。

The southwest mountainous area is a high mountain valley area in western China,geological disasters in this area are developed,with the characteristics of population and houses concentrated in the toe of the slope.It is urgent to find a new set of vulnerability assessment methods for effective and reasonable risk assessment in this area.This paper selects Lushui City,a typical western mountainous area,and uses GIS platform and logistic regression theory to conduct model evaluation,multivariate collinearity diagnosis,and fitness test,and finally establish a geological hazard risk assessment model.Considering the damage state and type that the hazard-bearing body may suffer,the classification and assignment table of the vulnerability index of different types of hazard-bearing bodies is constructed.For the first time,a vulnerability assessment method based on the distribution characteristics of disaster-bearing bodies such as population and houses in the southwest mountainous area is proposed.The results show that the northern part of Lushui County is a high-risk area,and most of the county and its surrounding areas are medium-risk and low-risk areas,which are basically consistent with the field survey and evaluation results.This risk assessment method can effectively reflect the risk status of geological disasters within the county.