The study of removal (detachment) and transitional regions of wind erosion upon ground indicator (Case study:Khartouran Erg)

Abstract

The result of wind dynamic (capacity and potential) is transport of soil or sediment particles and subsequent formative desert landforms based on the severity of erosion or sedimentation. The Khartouran region, because of its geology, geomorphology and climatology conditions is a special place in the arid region 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 wind erosion process in the Khartouran area can be categorized as origin, transport and sedimentation sites. In this research, the studied area was about 200000 ha, southwest of the town of Sabzevar covering sand origin and transport areas. The studies were carried out based on topographic, geologic maps, landsat images, aerial photographs and field observation. Based on these documents, the area was divided into a 9 km2 (3?3 km) grid and identity points of each grid were determined (214 points). On each identity point, indices of wind erosion (deflation, abrasion and accumulation), were collected. The results have shown two geomorphologic units (pediment playa) in project area and the geomorphologic facies (landforms) such as desert pavement, small yardang (kalotak), rebdou, nebka and sand ripple have been found by aeolian transport of sand. Based on ground indicators, determined removal and transit zones. Based on studies and results can conclude that these regions were affected by wind erosion in the past more than of current time and khartouran Erg is a result of wind activity in the past. Currently, the rate of sand flux and the balance between erosion and sedimentation are dominant factors in shaping geomorphologic facies (Aeolian landforms). <br /> <br />Key words: Khartouran Erg; Deflation; Abrasion; Wind erosion; Removal zone; Transit zone; Sand dunes; Wind erosion indicators