Hazards Analysis of Displacement of Sand Dunes in Sistan Plain

In Sistan plain, conditions for wind erosion and, consequently, sand spreads are provided. Due to the settlements in the wind erosion centers of this area, the necessity of determining the origin of sands, the analysis of the hazards caused by the displacement of sand dunes and factors creating these hazards are the goals of this study. It is a descriptive-analytical study based on both field and library methods. Initially, by studying the maps and field observations, it was cleared that the dry bed of the rivers of this region is the main origin of sands. Then, the morphometric parameters of several Barkhans (during 120-days winds) and the amount of their displacement were measured and recorded. The statistical analysis indicated that there was an inverse relationship between the length of Barkhans with their displacement, while there was no significant relationship between the other parameters and Barkhans displacement. The presence of Barkhans near ​​rural lands, the role of different land use, the effect of land roughness on the wind speed, and the amount of sand production in displacement of Barkhans can be considered as the main significant factors. The hazards of the sand dunes displacement at the villages include threatening public health, burying the villages, degrading the soil quality and destructing public infrastructure. Several factors such as intense and permanent winds, low-slope and low-roughness plain, fine-grained soil, successive droughts and vegetation loss play a role in the amount of sand displacement in Sistan Plain.