GIS-based Multi-Criteria Decision Analysis for landslide susceptibility mapping at northern Evia, Greece

This study evaluates the application of GIS-based Multi-Criteria Decision Analysis (MCDA) in landslide susceptibility mapping. The method was applied at the northern part of Evia Island (Greece) where landslides are frequent, often causing problems in local communities. GIS-based MCDA is concerned with how to combine the information from several criteria (factors) to form a single index of evaluation in a GIS environment. Weighted Linear Combination method of MCDA approach is applied, as it is the most commonly used. The Analytic Hierarchy Process (AHP) was also implemented for estimating the relative importance (weights) of the selected factors, providing the means to measure the consistency of decisions during the process. In the final map the landslide susceptibility conditions of the region are presented and classified by an easy-to-interpret scale. Its purpose is to convey information on slope stability conditions, in a way that can easily be for land use planning. However, specific uncertainties inherent in MCDA affect the reliability of the generated map and complicate its use. Through this study the most serious sources of uncertainty are identified and discussed, followed by suggestions on how to minimise them and ensure optimal use of the results by potential end users.