Landslide risk zoning using Spatial Multi-Criteria Evaluation method (SMCE) (Case study: Fereidan watershed)

Landslides are classified as natural disasters that pose financial losses and deaths in the country annually. Besides, identification of high risk areas can be effective in reducing the damage and improving decisions on land-development policies. Preparation of landslide zoning map makes it possible to identify the vulnerable areas and use them in various environmental programs. In this study, the multi-criteria methods were presented to create the landslide capability map using geographical information system and decision rules. The aim of producing landslide capability map is to reduce the risks of landslides and support land development policies in the watershed scale. In this regards, different factors such as geology, slope, aspect, landuse, distance to road, rivers and fault maps were employed. Additionally, slope and river maps were expressed as restrictions. After weighing the factors and sub-factors, the landslide sensitivity maps were converted to the values ranged as 0-1. Afterward, in terms of sensitivity the final map was classified to three classes of low risk, moderate risk and high risk. The results showed that some factors such as precipitation, geology and slope have the highest impact on landslide occurrence and should be considered with more emphasis in order to be used for planning and policy making in the study area. According to the results, the first group factors including geology, landuse, slope and aspect and the second group factors including land distance from fault, river, road and rainfall are weighed as 0.6 and 0.4, respectively.