H.Memarian - Soil and Water Engineering Services Company of Iran
M.Tajbakhsh - University of Birjand, Department of Agriculture
A.Safdari - Soil and Water Engineering Services Company of Iran
E.Akhondi - Soil and Water Engineering Services Company of Iran

By landslide zonation, critical areas in terms of slope instability to using in the sustainable development programs are prepared. Estarkhty watershed is located in the northeast of Iran and is a sub watershed of Atrak River. This watershed has five geological units that are included: SAhale and sandstone. limestone, andesite and recent alluviums. Because of high sensivity of Shouijeh formation, landslide zonation has done only on this formation. In this study Statistical Index method, was applied to landslide zonation and these factors were used: slope, aspect, the distance as to river and fault, soil, land use, soil hydrological groups, rainfall, elevation and direction of geological layers. In this method a weighted value for each class of parameters is defined and finally by considaring all of these values, the sum of these values for each pixel was estimated.

GIS , Landslide , Risk , Statistical Index , Shourijeh formation , Zonation