Document Type : Research Paper
Authors
Abstract
The results of wind dynamic are transport of soil or sediment particles and subsequently evolution of desert landforms according to the intensity of either erosion or sedimentation process.Geology, geomorphology and climatology conditions of the Khartouran region create a special situation on the closed basin of Dasht-e-Kavir. It is evident that the ecosystem balance of the region is affected by anthropogenic exploitation and wind activity, so this area has a geoecological structure with special features. The Khartouran Erg is resulted of wind activity on sand sources. The study area is located on the southwest of Sabzevar city with a total area about 200000 hectares. The study was carried out based on topographic, geologic maps, satellite images, aerial photographs, field observation and sampling. Based on the information and data, the study area was divided into grid cells of 3 km × 3 km. Surface soil or sediment of corner points of each grid was sampled (214 points). The results of granolometry analysis of soil or sediment samples were presented in seven maps. These maps show grain size distribution and consequently determine sand supplement potential of each point in different wind velocities.The granulometry analysis of samples showed that particle size with a range of 0.063 to 0.150 mm (the most vulnerable sand particle size to wind erosion) comprised the most percentage of distribution. Based on the results it may be concluded that these regions were affected by wind erosion in the past more rather than of current time and Khartouran Erg is result of wind activity in the past. Currently, the rate of sand movement intensity and the balance between erosion and sedimentation are dominant factors in shaping geomorphologic facies (Aeolian landforms).
Keywords
)