Dust temporal and spatial deposition affected by climate and soil mineralogical and chemical properties in a semi-arid area

The important process of aerosol dusting is of economic, environmental and heath significance. The objective was to investigate the climatic parameters including rainfall (R), wind speed (WS), temperature (T), and relative humidity (RH), as well as soil mineralogical and chemical properties affecting dust deposition rate (DDR), in a unique and rarely studied area, the Kuhdasht watershed (456 km(2)) of Lorestan province, Iran. Data were collected seasonally using glass-traps inserted in ten research stations to indicate DDR seasonal and spatial variations using ARC-GIS. The spatial distribution of organic matter (OM), clay and CaCO(3), and the mineralogical properties (using diffractograms obtained by XRD) of the dust and soil samples were determined. The city had the highest DDR decreasing toward the mountains. Spring (3.28–4.18 ton/km(2)) and autumn (1.82–2.52 ton/km(2)) resulted in the highest and the least DDR, respectively. The diffractograms indicated the sources of dust were local or from out of the borders. The clay minerals (kaolinite and illite) and the evaporating minerlas (gypsum, calcite, dolomite, and halite), detected in the soil and dust samples indicated their contribution to the process of DDR. According to the regression models and the correlation coefficients, DDR was highly and significantly correlated with R (R2= 0.691), WS (0.685) and RH (0.463) indicating such parameters can importantly affect DDR in the semi-arid areas.