Landslide Susceptibility Mapping for the Urmia Lake basin, Iran: A multi- Criteria Evaluation Approach using GIS

Although typically small in terms of their spatial footprint, landslide hazards are relativelyfrequent in Northern Iran. We assess landslide susceptibility for the nearly 20.000 km2 large study area of the Urmia lake basin which is dominated by agricultural land use but includes the major settlements areas of the East Azerbaijan province, Iran. Landslide factors are established in form of GIS dataset layers including topography, geology, climatology and land use. After pre-processing all data layers are standardized based on a fuzzy logic model. An Analytical Hierarchical Process (AHP) delivers the weights for the GIS-analysis.Datasets are combined by GIS spatial analysis techniques and a landslide susceptibility map of the study area is created. An existing inventory of known landslides within the case study area was compared with the resulting susceptibility map. We found that high susceptible zones cover about 4.47% (944 km2) of the total area whereby geological outcrops of sedimentary and volcanic formations such as volcanic ash contribute most to the landslide susceptibility. Due to the dynamic growth of settlements especially in the vicinity of the city of Tabriz landslide hazards may cause even more damage in the future.The resulting information of thisresearch is useful for a) a better understanding of existing landslides and their origins in North-Western Iran, b) supporting emergency decisions and c) prioritization of efforts for the reduction and mitigation of future landslide hazards.