Investigation the Factors Affecting the Landslide Using GIS and RS (Case Study Dosti Dam)

Construction of dams and the creation of lakes behind them can lead to geomorphic changes on their edges. One of the most common changes of the kind is landslide. Dosti Dam, as one of the largest storage dams in Iran, is facing such a critical situation. The purpose of this study is to identify the nature of the landslide phenomena, its causes, and the trends and future effects of landslide on the lake of Dosti dam. This research utilizes a descriptive-analytical and an experimental method by using IRS data, Digital Elevation Models (DEM), geological maps, satellite images and data from field and laboratory works along with observations of Earth sections, and sections of classes, and structural complications in the region to complete the geomorphological map, sampling of surface materials, mapping of sample slides for further monitoring and testing the particle size distribution. The results of study show 252 new landslides covering a total area of 123.8 acres (1/23 km). The volume of the sediment produced by these landslides which have entered the lake are about 8595433 m3 (8.59 km3). Causes of the landslide include geological, hydrological, anthropogenic, biological and climatic factors. The landslides have impacted the water quality, dam capacity and unstable domains near the lake, all of which render planning for landslide control a necessity.