Landslide Risk Assessment Based on GIS Multi-Criteria Evaluation: A Case Study in Bostan-Abad County, Iran

Although typically small in terms of their spatial footprint, landslide hazards are relatively frequent in Northern Iran. In this study, we combine Geographic Information System (GIS), remote sensing and derive a landscape susceptibility map for Bostan Abad County, Iran. The main objective is an inventory evaluation and zonation of natural landslides. This 2685 square kilometer sized county is one of the most important settlement areas in the East Azerbaijan province (North-Western Iran) also containing industrial regions next to the originally predominant agricultural land use. The basic landslides affecting factors are established in form of GIS dataset layers including topography, geology, climatology and land use which is derived from remote sensing imagery. After necessary pre-processing the original data sets a topology is created and active fault lines are buffered and overlaid. Vector layers are transformed into raster format and standardized based on a fuzzy logic model. An Analytical Hierarchical Process (AHP) is applied in order to derive the weights associated with suitability (attribute) map layers. And based on these weights, GIS datasets are combined by weighted overly techniques and the landslide susceptibility map of the study area created. The resulting information is useful for (a) a better understanding of existing landslides and their origins, (b) supporting emergency decisions and (c) prioritization of efforts for the reduction and mitigation of future landslide hazards.