A comparative study of Analytical Hierarchy Process and Ordinary Least Square methods for landslide susceptibility mapping using GIS technology

Abstract: This work presents Analytical Hierarchy Process (AHP) method available in Geographic Information System (GIS) to identify and classify the Penang Island according to the grade of present or potential danger of land failure happening. Landslide susceptibility zonation map has been generated by considering seven factors. Sensitivity analysis was performed in detail by varying the contributing factors weights and their effects on defined landslide susceptible locations. In other part of the analysis, ordinary least square (OLS) technique has been used to estimate weights of point parameters then its result compared with AHP technique result. Finally, the landslide susceptibility maps resulted from AHP and OLS method has been compared to the landslide inventory map containing 355 real occurred landslides in order to verify the practicality of susceptibility maps. The outcome was that the 75% of occurred land failures fit into the very high and high susceptibility class of AHP map (using seven parameters), while this is 73.8% in the case of AHP with point parameters (using four parameters), and 65.8% for the OLS map. As conclusion, the AHP method yields reasonable results which make it reliable and credible approach in comparison with OLS, especially in the case of using large number of landslide contributing factors.