Determination of Geomorphic and Land use Characteristics of Dust Source Hotspots (Case Study: Khorasan Razavi Provience)

Dust phenomenon is the One of the most important hazards in the dry and semi-arid region. The occurrence of this phenomenon is accompanied by many physical and financial losses. In this research, was studied the characteristic of land use and geomorphology dust source in Khorasan Razavi Province. At first, 65 soil dust sources were identified for the time period (2005-2016) by using the dust enhancement indices on the MODIS images. Then geomorphologic and land use maps were prepared and the dust source area were overlaid on these maps. The results indicate that in geomorphology map, 81 percent of the dust source area in the plain head unit occurred, accounting for about 71.5 percent of the all area. At other geomorphic surfaces, dust sources area are located in the Playa unit (10.7% in 17.5% of the area) and in the mountains (6.4% in 14% of the area). The results of land use survey showed that the highest number of dust source area occurred in poor rangelands (35.3%) and dryland lands (27.6%), which covers 35.3% of the total area. By calculating the dust rate at different levels, it was determined that in addition to the type of geomorphology and land use structure, there is a close correlation between the area and the number of dust source per unit with the emission rate of dust.