基于GIS的公路边坡地质灾害危险性评价

Risk assessment of highway slope geological disasters based on GIS

针对丹巴县公路边坡地质灾害频发状况以及区域分布的特点,对丹巴公路边坡灾害进行了危险性分区研究。通过分析自然环境概况与公路地质灾害特征,选取坡度、岩土类型、降雨、河网密度、植被覆盖率和地震6个因素作为地质灾害危险性评价指标体系;采用影响因素叠加法构建危险性评价指数的数学模型,并运用云模型-层次分析法(CM-AHP法)计算各评价指标的权重;基于ENVI 5.2与ArcGIS 10.2软件计算生成《丹巴县公路边坡地质灾害危险指数图》,同时考虑公路工程特点,划分了II低危险区、III中度危险区、IV高危险区和V极高危险区4个等级16个灾害区,依据定量区划范围并结合定性分析的评价方法对丹巴县公路进行地质灾害危险性进行评价。研究结果表明,评价结果与公路边坡灾害实际情况吻合,可为四川省丹巴县公路边坡灾害的预防治理工作提供一种新的途径。

The risk regionalization of highway slope disasters was studied according to the situation of frequent geological disasters and the regional distribution characteristics of highway slope in Danba County.By analyzing the natural environment and highway geological hazard characteristics,the slope,rock and soil types,rainfall,river network density and vegetation coverage as the main factors were selected to build risk assessment index system.Based on the superposition method of the influencing factors,the mathematical model of the risk assessment index was established,and the weight of each evaluation index is calculated by using cloud model-analytic hierarchy process(CM-AHP method).Based on the software of ENVI5.2and ArcGIS10.2,the hazard index map of"Danba county highway slope geological hazard"was plotted.In view of the hazard zoning index and the characteristics of highway engineering,the highway slope disasters in Danba county was divided into4grade16disaster areas,such as the low risk area,medium dangerous area,high dangerous area,extremely high danger area.According to the evaluation method of quantitative regionalization range and qualitative analysis,the geological disasters risk assessment of highway in Danba county was carried out.The evaluation results coincide with the actual situation of highway slope disaster,which can provide a new way for the prevention and treatment of Danba County Highway slope disaster in Sichuan province.