Wind regimes and aeolian sand transport in Lut Desert of Iran
1, Christian Opp2
1University of Marburg, Faculty of Geography, Marburg, Germany, 2Desert Division, Research Institute Forests & Rangelands Iran, Tehran, Iran
Wind plays very important role to form dunes. Wind energy controls the rate of sand transport in arid environments. For measurements of prevention or protection against aeolian erosion, basic knowledge of climate, especially of the wind conditions and the resulting aeolian forms, especially dunes are a necessary prerequisite.
Wind records for 13 metrological stations around Lut Desert area analyzed with standard aeolian-sediment transport methods. Hereby wind rose, Drift Potential (DP), Resultant Drift Direction (RDD), Resultant Drift Potential (RDP) and the ratio of RDP/DP have been calculated. The map of morphology of Lut (Yalan) sand sea was surveyed by using Landsat ETM data, aerial photographs, Google Earth scenes and field operations. The spatial distribution of drift potential was also mapped using GIS and geo-statistic methods overlaying on sand dune map. Finally, the activities of sand dunes were classified.
The results show that the drift potential (DP) on Lut desert is generally high (DP >400) in the central and eastern areas, where effective winds are from northeast and southern direction. Other areas have moderate drift potential (DP 200-400), which is predominantly of northwestern wind direction. Meteorological observations show that there are effective winds of two directions (south and north) as well as west and northwest for dune formations. While the southern and northern as well as northeastern winds transport the sand to the Lut Desert, the northwestern wind forming the dunes. This results proved by localized RDD and morphology of dunes which formed star and linear dunes. In addition, the results demonstrate that topographic obstacles influence on morphology of sand dunes in northern area of the Erg and forming the highest stars dunes in Iran.