Mapping of Landslide Susceptibility Using Analytical Hierarchy Process (AHP) in the Ain Smara and its Surrounding Areas, Algeria (Northeastern of Algeria)

Abstract

Man has always sought to cope with geological hazards. Landslides are one of the most common natural hazards. Landslide sensitivity mapping is one of the mitigation efforts to reduce the risk of landslides. In this sense, this mapping is to identify the areas most susceptible to landslides. This work is based on remote sensing and the geographical information system as basic tools to establish a map of the areas of susceptibility to landslides in the region of Ain Smara and its surrounding areas. For a landslide risk assessment in our study area, we used the Analytical Hierarchy Process (AHP) method which is very effective in arid and semi-arid regions. This technique is a quantitative method based on a qualitative evaluation of certain phenomena. This method has been applied in the Constantine region of Algeria, as well as in other regions of the world to determine the weights of each phenomenon influencing the landslide. Data used to map landslide susceptibility in the study area include slope, Lithology, slope aspect, drainage distance, fault distance, distance from streams, distance from roads, and land cover. The data were then spatially analyzed using the overlay function in ArcGIS 10.2 to map the landslides. Landslide susceptibility in the area of Ain Smara and its surrounding area consists of five classes: very low, low, moderate, high, and very high. The results of this study were verified based on actual landslide locations within the study area. In our study area, we noticed the dominance by very low susceptibility to landslides per percentage area of 30.27%, low susceptibility of about 20.08%, moderate susceptibility of about 17.23%, high susceptibility of approximately 20.12% and very high susceptibility of approximately 12.30%. The landslide susceptibility map shows that the very high susceptibility zone is located in the western part of the study area, geologically covered by the formation of Pliocene clay and a denudation morphology.