Landslide susceptibility mapping using the analytical hierarchy process and the Geographic Information System along the Agadir Ida Ou-Tanane province, Morocco

Abstract

This study focuses on evaluating the susceptibility to landslides in the Agadir Ida Ou-Tanane province following the significant seismic event on September 8, 2023, employing Geographic Information System (GIS) and Analytical Hierarchy Process (AHP). The region, characterized by tectonic activity and diverse lithology's such as clay, limestone, and alluvium, coupled with steep slopes, is inherently prone to landslides. Utilizing the AHP methodology, we integrate ten factors influencing landslide vulnerability: lithology, slope, earthquakes zone, rainfall, land cover (LULC), distance from faults, hypsometry, drainage, distance from road, and aspect to map susceptible areas effectively. Pairwise comparison matrices and expert assessments were employed to establish the relative significance of these factors, with the reliability of judgments evaluated through the calculation of the consistency ratio (CR). The resulting map depicting landslide susceptibility illustrates a spatial continuum from very low to very high susceptibility areas. Given the active tectonic setting of the region, lithology and slope emerge as the predominant factors influencing susceptibility. Model validation was conducted using observed landslide occurrences, enhancing the applicability of this mapping for land-use planning and risk management purposes.