基于GIS的中国泥石流易发性评价

Susceptibility evaluation of debris-flow in China based on GIS

探讨全国泥石流易发程度,为地质灾害防治规划、宏观层面国土空间布局等提供依据。以中国内地(未包含香港、澳门和台湾)为研究区,选取起伏度、地貌类型、活动断裂距离、岩组(性)、年平均≥50mm暴雨日数、土地利用程度等6个易发性评价因子,基于1km×1km评价单元,采用概率比率模型,进行了易发性评价,形成了全国泥石流易发程度分区,并对结果进行了检验。评价结果表明:高易发区面积占7%,泥石流数量占全部的52.50%;中易发区面积占的28%,泥石流数量占33.51%;低易发区面积占28%,泥石流数量占11.45%;不易发区占37%,泥石流数量占2.55%。

The paper discusses the susceptibility degree of debris-flow throughout the country to provide basic evidences for the prevention and planning of geological disasters,the spatial layout of lands at a macro level,etc.In this study,taking China's Mainland（not including Hong Kong,Macao and Taiwan） as the research area,the susceptibility evaluation is conducted based on 1 km×1 km evaluation unit,by selecting six factors such as relief amplitude,geomorphic type,active rift distance,petrofabric（lithology）,rainstorm days（the average rainfall is ≥50 mm） and land use degree and using the probability ratio model.The sub-areas subject to the susceptibility degree of debris-flow throughout the country are formed and the results are tested.The results from the evaluation indicate that the area with high susceptibility accounts for 7% and the number of the debris-flow accounts for 52.50% of the total quantity of the debris-flows;the area with medium susceptibility accounts for 28% and the number of the debris-flow accounts for 33.51%;the area with low susceptibility accounts for 28% and the number of the debris-flow accounts for 11.45%;the area with little susceptibility accounts for 37% and the number of the debris-flow accounts for 2.55%.