GIS-AHP-Based Landslide Susceptibility Assessment of the Bradost Anticline, Northern Iraq

Abstract

The use of landslide susceptibility assessment is a vital step for sustainable land-use planning and risk mitigation, especially in mountainous areas and in complex tectonic and geomorphological environments. The present study aims to assess the landslide susceptibility in the Bradost Anticline through an integrated Geographic Information System (GIS) and Analytic Hierarchy Process (AHP) approach. The following 10 conditioning factors were considered: geology, lineament density, slope, elevation, stream density, gully density, slope curvature, topographic wetness index, normalized difference vegetation index, land use/land cover. All the factors were treated, standardized and visualised as thematic GIS layers. The AHP was then applied to normalize the weights and weighted layers were combined to create a landslide susceptibility map. Very high, high and moderate stability zones cover 11.36%, 25.05% and 29.87% of the area, respectively. The low and very-low-stability areas constitute 23.05% and 10.67%, respectively, showing high or very high landslide susceptibility (33.72%) in the study area. The highest weights were recalculated for geology, lineament density, and slope (0.190, 0.188, and 0.179, respectively). An overall accuracy of 83.06%, a kappa coefficient of 0.787, and an area under the ROC curve of 0.894 were used to validate the model. These outcomes show high level of agreement with the observations in the field and high level of discriminatory performance. The framework can be used as a regional screening basis for landslide mitigation, land-use planning and infrastructure protection in vulnerable mountainous terrain.