Document Type : Research Paper
Authors
1 MSc Student, Faculty of Rangeland and Watershed Management, Gorgan University of Agricultural Sciences and Natural Resources, Iran
2 Professor, Faculty of Rangeland and Watershed Management, Gorgan University of Agricultural Sciences and Natural Resources, Iran
Abstract
Landslide is one of the natural hazards that makes numerous financial and life damages each year. By landslide hazard zonation, we able to detect susceptible areas to landslide and with applying developed methods and suitable management the abundance of land sliding and the amount of damages will be reduced. In this study potential landslide hazard evaluated using multivariate regression model at a part of Alamout watershed in general level (1:50000 scale). So first, landslide distribution map of area prepared using study of air photos and field surveying. After reviewing available resources along with reviewing the benefit of experts, all factors that can affect landslide were extracted and among them eight parameters including (lithology, slope percent, aspect, height, distance to fault, land use, rainfall and earthquake acceleration) were selected as landslide effective factors. AHP and pair comparing technique were used for numerical weighting to qualitative categories of land use, aspect, and lithology parameters. Homogeneous units map prepared using overlaying 8 maps of landslide key factors, and by crossing of homogeneous map and landslide distribution map. Categories of each parameter were detected in each landslide, and with weighting average of them, the effect of each parameter was determined in each landslide. Therefore 84 observations prepared for statistical analysis of landslides. Results showed that 5 parameters including lithology, slope, height, distance to fault and land use have meaningful relation with landslides that determining coefficient between these parameters as independent variables and logarithm of landslides area as dependent variable was 60.7%. Landslide hazard zonation map and landslide distribution map were crossed and efficiency of model was evaluated. The Chi square test was used for comparing of difference between hazard classes of model. Results show that model has higher efficiency in higher classes of hazard. Results show also measured chi square rate is meaningful at 99% of confidence interval, and there is suitable separation among landslide hazard classes.
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