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Studying landslide triggering factors and zoning of their hazards can effectively help in reducing the damages. This research was an effort in this regard, studying landslide triggering factors and mass movement hazard zoning for the Germichay watershed, zoned by both Multiple Regression (MR) and Analytical Hierarchy Process (AHP) methods. Finally, a regional model has been presented.
Methodologically, first the landslide triggering factors of the area were studied; then, the most important factors along with their priority arrangement including lithology, slope, land use, lineament factors, precipitation, aspect and altitude were investigated. Next, the map of landslide distribution was prepared. In MR method, four factors were examined, and the map of their homogeneous units was prepared using GIS. In order to quantify the factors and give them weights, landslides percentage in different units was determined. Employing the stepwise regression method, the zoning model was found after omitting the precipitation factor. In AHP method, the above mentioned seven factors were used where the proposed factors were compared in pair, with their weights being then determined. Moreover, cumulative curve was used to classify the above factors, and the landslide value (%) was then determined for ranking. Eventually, according to the weight earned by each factor as well as rank values, the zoning model was finalized.
Comparing the results of these two methods, it was found that the AHP method is clearly more accurate and reliable than the MR method as the former contained more variables as well as a rational classification without any expert's bias/interference. Therefore, the AHP model was evantually evantually selected as the final model.