National-Scale Risk Assessment of sinkhole Hazard in China

Assessment of sinkhole hazard (karst collapse and mining collapse) at a national scale is very important for government's decision-making on land-uses. This paper introduces the analysis and assessment of sinkhole hazard using GIS functions such as buffer analysis, overlay analysis, and spatial analysis. Factors of the risk assessment include types of carbonate rock, the geomorphological settings, hydrogeologic conditions, human activities, and land use. Human activities consist of urbanization, mining, and distributions of highway and railway. All factors were digitized as corresponding GIS coverages and assigned weight values based on the distribution and probability of sinkhole collapses. The Analytic Hierarchy Process (AHP) was used to determine the weight of each factor. The assessment result is divided into five levels: very high risk, high risk, medium risk, low risk, and very low risk. The very high-risk areas are mainly located in Guangxi, Guizhou, Yunnan provinces. A few very high risk areas are sparsely distributed in Hubei, Hunan, Chongqing, Sichuan, and Shaanxi.