Risk zoning and effective factors on mass movements in the southern slope of Damavand

Land and geomorphic hazards are important natural hazards that cause many human and financial losses in all countries of the world and especially in Iran. Therefore, studying and preparing a risk zoning map is one of the priorities of every country today. In this research، the investigation and zoning of the risks of mass movements in the southern slopes of Damavand have been discussed. To prepare the zoning map, at first, the effective factors in the occurrence of mass movements were identified using theoretical foundations and research background. In this way, climatic parameters (rainfall, temperature, frost), human factor (communication routes, land use), topographic parameters (slope and height and slope direction), geological parameters (rock type, distance from the fault), hydrological parameters (distance from the river) as variables. The main ones were identified. In this area, a total of 46 cases of landslides have been observed using aerial photos، of which 36 cases are located from Pleur to Reine. AHP hierarchical analysis model will be used to model and predict the relative risk of mass movements in this research. For weighting and pairwise comparison of variables and sub-variables, the opinions of 30 experts were used. Finally, the studied area was prepared using the hierarchical method of zoning the risk of mass movements in five zones: very dangerous, dangerous, medium-risk, low-risk and safe. The very dangerous area with the output pixel number of 3773 covers approximately 4.8% of the area. The dangerous area covers 20% of the area with the number of 15.779 output piskels. The medium risk area with the output pixel number of 57335 is the widest area in the region, which covers an area of 72.8% of the area. The area with low risk with the number of output pixels of 1302 is approximately 1.6% of the area and the safe area with the number of pixels is 380 is the smallest area of the area, which covers about 0.4% of the area.