Slope instability hazard zonation in Baleghluchai watershed in Ardabil using AHP Fuzzy method

Landslides and slope instabilities are among the important natural hazards, which cause human and financial casualties and loss of economic resources every year. These hazards mostly occur in natural slopes or those manipulated by human. Landslide hazard zonation is one of the methods by which, areas prone to landslide occurrence can be determined and plannings can be done using the obtained zonation maps to reduce the casualties. The aim of this contribution is to study landslide hazard zonation within the Baleghluchai watershed in NW Iran. First, the main factors including the slope and its direction, geology, soil, climate, distance from the road and river and land usage were determined. The method of current investigation was Fuzzy AHP in the GIS environment, based on which, after preparing data layers using the above-mentioned parameters and giving weights to them in the GIS environment, the landslide potential map, as well as classification was carried out by Fuzzy AHP method. Results showed that the largest part of the watershed (32.21%) has low landslide potential, while about 13.5% of it has very high potential. Areas with very high and high landslide potential (327.39 km2 area) are mainly located in the northwest of the watershed, with some small areas distributed in the south and east, while areas with very low and low potential (504.06 km2) are mainly found in the central to northwestern and southern parts of the watershed.