Landslide Inventory and Susceptibility Mapping in the Río Chiquito-Barranca Del Muerto Watershed, Pico de Orizaba Volcano, Mexico

Abstract

In volcanic environments, stratovolcanoes have great potential to produce landslides and debris flows due to their high relief. Their volcanic activity can trigger voluminous landslides along stream systems; however, these are rather infrequent. On the other hand, small but hazardous non-magmatic landslides occur frequently during volcanic repose. InMexico, Pico de Orizaba presents the greatest potential threat for the formation of landslides and debris flows triggered by non-magmatic activity because of its large area of weakened rocks at high altitudes and high seasonal rainfall. The Rio Chiquito-Barranca del Muerto watershed on the southwestern flank of Pico de Orizaba was selected as a case study. This chapter provides an overview of the on-going International Program on Landslides (IPL) project IPL170 “Landslide susceptibility and landslide hazard zonation in volcanic terrains using Geographic Information System (GIS): A case study in the Rio Chiquito-BarrancaDelMuerto watershed, Pico de Orizaba volcano,Mexico”. First, the project aimed to derive a landslide inventory map from a representative sample of landslides using aerial photography and field investigations. Next, Multiple Logistic Regression was used to examine the relation between landsliding and several independent variables (elevation, slope, contributing area, land use, geology, and terrain curvature) to create the susceptibility map. With six independent variables, the multiple logistic model susceptibility map tended to overpredict landslides at 10-m pixel resolution. However, the model was statistically valid and able to predict 72% of existing landslides. The implementation of a landslide inventory and susceptibility mapping techniques showed the feasibility of the method to be used in other volcanic areas of Mexico.