基于聚类和最大似然法的汶川灾区泥石流滑坡易发性评价

选择坡度、相对高差、地表径流深和地震烈度4个震后地质灾害的主控因素作为评价影响因子,采用聚类分析和最大似然法评价汶川极重灾区(四川省部分)震后地质灾害的易发性.结果表明:聚类分析和最大似然法这种非监督分类的方法适用于没有足够训练数据的情况,可以快速对一个大区域的地质灾害易发性进行评估；从得到的易发性评价图中可知,在大块的高易发区内存在一些小的极低易发区,这些区域可以作为安全的居民点使用,在极高易发区和高易发区以及高易发区与极低易发区分界线附近,地质灾害点分布比较密集.

Susceptibility mapping of landslides and debris flows in 2008 Wenchuan earthquake by using cluster analysis and maximum likelihood classification methods

Cluster analysis and Maximum Likelihood Classification（MLC） methods are introduced to map the susceptibility of post-quake geo-hazards in the Ms 8.0 Wenchuan earthquake area.Four variables including slope gradient,relative relief,seismic intensity and surface runoff are chosen as predominant factors of the susceptibility mapping.The mapping result shows that this approach has the advantage of rapid evaluation,and is applicable even when there is short of training data.Five kinds of susceptibility（very low,low,moderate,high,and extreme high） are assigned to the study area by virtue of expert experience and geo-hazard density.The final map gives a reasonable assessment of susceptibility of post-earthquake geo-hazards in the area.It is found that there exist safety spots within the region of high danger,which are suitable for habitations and facilities.Moreover,the hazard density near the boundaries between extreme high and high regions,or high and very low regions is larger than other regions.