Landslide susceptibility analysis based on a semiquantitative method in the sierra-costa region, michoacán, mexico

Abstract

ABSTRACT Landslides are one of the most common and destructive natural hazards in the world. The Sierra-Costa region in the southwestern part of the Michoacán state, Mexico, is prone to landslides because of its physiography, geology, and climate. In particular, the area is prone to shallow landslides in the weathered rock that is triggered by heavy rainfall. Here, we present a susceptibility model for this hazard that is based on an analytical hierarchy process (AHP). To assess landslide susceptibility, we designed maps of different parameters (lithology, distance to faults, slope gradient, slope aspect, geoforms, soil type, distance to rivers, and land cover). The landslide susceptibility map includes five classes: nullnull, low, moderate, high, and very high susceptibility. About 5% of the area is categorized as having null landslide susceptibility class; 18% is low susceptibility, 28% moderate susceptibility, 29% high susceptibility, and 20% very high susceptibility. The very high susceptibility areas are dominantly underlain by limestone and weathered granite and are near faults. We evaluated the precision of the model using the receiver operating characteristic (ROC) curve method. The susceptibility model represents the first step in understanding the distribution of landslides in the Sierra-Costa region.