Quantitative Analysis of Landslide Risk and Its Zoning in Alamut River Basin Using Logistic Regression Method

Landslides and slope instability are major hazards to human activity, which cause damage, this instability and hazard are potential and damaging phenomena, our country is mainly mountainous topography, tectonic and seismic activities. The high humidity, diverse geological and climatic conditions have created most of the natural conditions to create a wide range of landslides. The purpose of this study was to identify the effective factors in landslide generation and identify potential landslides in Alamutroud basin in Qazvin province using logistic regression method. In this study, landslide distribution map of the basin was prepared by studying aerial photos and field surveys using GPS and satellite imagery. Eight effective factors including slope, slope direction, sea level rise, distance from riverbed, land use, lithology, distance from fault and drainage network density were used and then processed using Matlab software. , ARC GIS, IDRISI and EXEL. According to the results, 58.26% of the catchment area is in the low and very low risk zone and 17.44% in the high and very high risk area. Also the factors of height and distance from the ranch have the highest scores in landslide creation. Also the model validation indices including pseudo ROC and R_square ChiSquare were calculated /957 -2511/283 and/ 3518  respectively which have acceptable validity.