Analysis of geomorphologic- anthropogenic changes in sources of Sand and dust storms (Case study: Damghan Erg)

Sand and dust storms occur when unchecked, strong or turbulent winds combine with exposed loose soil dry surfaces. These conditions are usually exacerbated by human activity and land use change in semi-arid and arid regions. The Damghan region, due to its geoecological structure, has created a special features in the arid region on the closed basin of Haj Aligholi. At present the ecosystem balance of the region is affected by anthropogenic exploitation and wind activities. The aim of this study was to investigate the priority of sand resources in the aeolian process. In this study, we were compared the composition and variations of grain size in land natural units (landforms) and human activity - based units (Landscape). In each unit of sand source were taken soil or deposit samples. The results of granulometry show that Agricultural Land Unit contain more than 60% of particles larger than 2000 microns; As a result, this unit is more resistant to wind erosion than other units. Whereas, this value is about 15% for the most sensitive landforms (alluvial plain with water erosion). On the other hand, the granulometry results of particle below 2000 micron indicate that Agricultural Land Unit contains the most vulnerable particles to wind erosion. This means that agricultural land has a high potential to provide sand resources in the process of wind erosion.