Determinación de la susceptibilidad a los deslizamientos en el Valle de Siguas - Arequipa. mediante aplicación del método Mora - Vahrson

Abstract

The Siguas Valley, located in the Arequipa region, is an area of intense agricultural activity where slope instability has caused significant impacts on both infrastructure and land use. This research determines landslide susceptibility through the application of the Mora- Vahrson method, adapted to include soil moisture as a triggering factor. The hypothesis is that the northwestern part of the valley is the most susceptible to landslides due to the interaction of oversaturated soils, unfavorable geomorphology, and unconsolidated lithology. The study integrates data on geology, geomorphology, slopes, land cover, and satellite- based moisture indices in a weighted overlay analysis using ArcGIS Pro. The results show that areas with unconsolidated materials, steep slopes, and land cover altered by human activity present greater instability. Furthermore, it is confirmed that over-irrigation in the valley has led to soil oversaturation, reducing its strength and favoring the occurrence of landslides. It is concluded that the combination of geological, slope, and moisture factors determines the distribution of susceptible zones. As a mitigation measure, reforestation with eucalyptus trees is recommended over 40 hectares to reduce excessive infiltration, along with continuous monitoring of the area and regulation of agricultural irrigation. The results of this study provide a useful tool for managing geological risk in regions with similar conditions.