Landslide susceptibility assessment in semiarid mountain watershed Using weights-of-evidence and statistical method (Saeedabad-chai Watershd- North of Sahand Mountain)

The aim of this study is assessing and mapping landslide susceptibility in watershed of semiarid mountain areas. Saeedabad-chai Watershd is located on the northwest of Iran and the North of Sahand Mountain. This study is using Bivariate Statistical Analysis (BSA)، weights-of-evidence (WOE)، GIS. The results of this assessment show that causative factors as slope (∑wƒ= + 3. 965)، landuse (∑wƒ= + 0. 759)، distance of road (∑wƒ= + 1. 498)، lithology (∑wƒ= + 0. 424)، rainfall (∑wƒ= + 0. 388)، distance of rural (∑wƒ= + 0. 161) play a major role in the landslide occurrence. There is a negetive relationship between landslides and distance of fault (∑wƒ= - 0. 006) and distance of channel (∑wƒ= - 0. 325) in the Saeedabad-chai Watershd. The medium، high and very high susceptbility zones make up 43. 116 % of the total study area. The acuuracy of the map was evaluated by (Li) index. This index shows that 92% of landslides occure on medium، high and very high susceptbility zone.