Spatial Analysis of Dust Storms in Iran based on Climatic and Vegetation Characteristics

Dust storms are one of the harmful climatic hazards that occur as a result of extensive ecological imbalances. Geographical location of Iran, i.e., the arid and semi-arid belt of the world, provides proper conditions for the occurrence of dust storm hazards. The present study aims to identify and spatially analyze the sources of Iran dust storms by using the National Centers for Environmental Prediction (NCEP/DOE); European Centre for Medium-Range Weather Forecasts operational (ECMWF) ERA-Interim reanalysis datasets and the records of 52 synoptic stations from 1984 to 2016. Since Dust storms occur in areas with disrupted ecological balance One-dimensional radiative-convective model (RCM) implemented to calculate the heat fluxes and heat balance at the ground. Finally, eight environmental parameters have been selected to identify dust sources in Iran. Combining the Analytic Hierarchy Process (AHP) and Index-Overlay (IO) method, the dust sources were detected and evaluated through the land-use maps and the Normalized Difference Vegetation Index (NDVI). The results indicated that before dust storm, the stored energy of the surface is high due to the increase in surface temperature and dry air. Therefore, the released energy through the surface instability forms severe winds in the stormy areas. After energy discharge, the amount of stored energy at the surface decreases drastically on the dusty day. In recent years, due to higher NDVI variations and exacerbation of soil erosion, higher potential dust sources have been found in the southern, southeastern and southwestern parts of Iran. In addition, considering the fundamental changes in NDVI, around the Lake Urmia in the northwest of Iran and eastern Caspian Sea, these areas also have more potential dust sources.