Landslide Hazard Zoning using Gamma Fuzzy Operator (A Case Study: Taleghan Watershed)

One of the slopping processes which creates tremendous damage in many locations of Iran and the world is landslide phenomenon. Creating a landslide susceptibility map provides the possibility to recognize susceptible areas and to verify them in the environmental programs. The purpose of this research is to map the susceptibility of landslide in Taleghan watershed by establishing informational layers and effective factors in the occurrence of landslide via gamma fuzzy operator. Input information set in assessment of potential hazardous landslide include nine factors: elevation, slope, aspect, geology, land use, vegetation density, and distance from road, distance form fault and drainage density. Landslide points of watershed have been converted to landslide areas using satellite images and level of correlation between each effective parameter in landslide occurrence and landslide areas was determined by the frequency ratio. Next, zoning maps of landslide were created using gamma fuzzy operator 0.7, 0.8 and 0.9. The result from the quality sum index showed that a gamma fuzzy operator with a value of 0.7 had a higher accuracy compared to the other two gamma fuzzy operators in making a landslide hazard susceptibility map in the study area.