Statistical Studing of Factors and Mass Movements Happening Hazard Zonation in " Chenaran watershed"

Chenaran watershed is located in the northern Khorasan Province, at northern slopes of Aladagh range and is one of the Atrak river subbasins. Several large scale landslides occur in this basin which led to a lots of damages. In order to recognize the mass movements, all aspects of the factors and processes which continually affect on slopes and led to instability, of slope should be identified. In this research the geology, hydrology, topography and landcover-landuse factors were studied.At the first step, the weight of quantitative & qualitative effective variables in basin mass movements was determined, by using “Landslide Index Method” (LIM) model. Then by obtaining of “Logistic regression” model of mass movements in basin, final map for prediction of mass movements probability with 2 classes was prepared. According to the vulnerability about landslide hazard, subbasins were ordered by calculation of weighted accumulation per hectar. Thus, the “Shurijeh Formation” (Ksh) consists of clastic rocks (siltstone and marl) and evaporites, which are impermiable, with assistance of slope, altitude, ground waters, landuse and Chenaran river under cutting, are the most important factors for mass movements in chenaran watershed.