Surface Shear Resistance of Dust Hotspot Soils on a Small Scale in Southwestern Iran

This research was conducted to quantify the direct and indirect effects of surface shear resistance (SSR) on dust hotspot soils in the southeast of Ahvaz city, Khuzestan, Iran. For this purpose, we measured certain parameters, including the mean weight diameter (MWD) of dry aggregates, particle size distribution (PSD), permanent wilting point percentage, soil moisture percentage, sodium absorption ratio (SAR), organic matter, calcium carbonate (CaCO3), and soil electrical conductivity (EC). SSR was measured in 100 different locations of the field conditions using the modified shear device (MSD), specifically designed and manufactured to perform this project. The effects of soil properties on SSR were investigated employing path analysis and multi-linear regression approaches. SSR values (0.32-0.98 kPa) in the dust hotspot soils indicated that these soils are highly susceptible to wind erosion and have a high variability (4.26%). The best regression pedotransfer model accounted for 42% of SSR variations by soil estimating parameters. MWD and CaCO3 were identified as the most sensitive parameters in SSR estimation in the dust hotspot soils in southwestern Iran. MWD and CaCO3 (via PSD) showed the highest direct and indirect effects on SSR, respectively. In general, SAR on SSR represented no significant effects in this region due to high EC values.