Assessment of the Effects of Rainfall Frequency on Landslide Susceptibility Mapping Using AHP Method: A Case Study for a Mountainous Region in Central Vietnam

Abstract Vietnam’s mountainous regions often encounter landslides, frequently resulting in fatalities, infrastructure damage, and landscape destruction. A landslide susceptibility map is an effective tool for mitigating disaster impacts on hazard-prone areas. This study investigates the applicability of the Analytic Hierarchy Process to produce a landslide susceptibility index. Eight major impact factors are analyzed using SAGA, a GIS-based toolkit, including slopes, aspect, land use, soil type, elevation, distance to road, distance to stream, and antecedent rainfall. Four landslide susceptibility maps are produced corresponding to frequency scenarios of 3-day antecedent rainfall data which is taken from Regional Frequency Analysis (RFA). We assess the modeling performances using Area Under the Curve (AUC) index and the results show that the AHP model has good performance. The findings demonstrate a significant influence of rainfall antecedent conditions on the susceptibility map of landslides in this study area.