Geomorphological Analysis of Dunes Drifting Process in the East of Sistan Plain During Recent Draughts

Sistan plain that is located in east of Iran has a dry and unpleasant climate and sand storms and movement of dunes are one of the threatening factors in this area. Draught occurrence in Sistan region and subsequent decrease in vegetation, dryness of the Hamoon Lake and 120- Days wind caused windy erosion and sand storms conditions. These factors caused additional velocity of dunes movement in the region and making plentiful sandy-hills. Kaftaregi and then 6 hills of loess (Barkhan) were chosen as samples in field calculations. The rate of movements was calculated in 3 months and adjusted in a table. The results of field investigations showed that wind in high speed are caused increasing dunes movements and damaged farming fields, villages, roads, irrigation channels, installations. After determining the rate of dunes movement, movement of them will be forecasting for further years. Satellite images and field investigations showed that water storage of Chah Nimeh which is the only drinking water source of people, would be threatened by sand storms in the future, and water storage will be in serious danger, if there isn’t a way to prevent the rushing of sands. In this article, the attempt will be to survey the effect of 120- days wind in producing sand storms, and then mathematical model will be determined between geomorphic parameters. At the end, dunes drifting and damages will be forecasted by satellite images, topographical maps and field investigations.