In situ field measurement of wind erosion and threshold velocity in relation to soil properties in arid and semiarid environments

Abstract

Field measurement of wind erosion linked to soil properties improves our understanding of erosion processes in arid and semiarid regions to combat this environmental threat. The aim of this study was to investigate wind erosion and threshold velocity (Vt) in relation to soil properties using a portable wind tunnel in 60 sites of Kerman, the largest province of Iran. The result indicated that wind erosion rates ranged from 0.03 g m−2 min−1 to 3.41 g m−2 min−1, indicating a wide variability in the erodibility of soils. Wind erosion was inversely attributed to Vt following a power function. In all cases, the influence of soil properties on wind erosion was supported by their opposite effect on threshold velocity. Clay and silt fractions, mean weight diameter (MWD) of aggregates, dry stable aggregates (DSA), shear strength, surface gravel, the concentrations of K+, Ca2+, and Mg2+, soil organic carbon (SOC) and calcium carbonate equivalent (CCE) were inversely proportional to wind erosion rates following nonlinear functions. Wind erosion was significantly increased as electrical conductivity (EC) and sodium adsorption ratio (SAR) increased. Critical values of 5.7–8.9 m s−1 at 10-m height for Vt, 7% for clay content, .3 mm for MWD, 25% for DSA, and 5% for surface gravel were recognized, approximately. Multiple regression analysis indicated that SAR and MWD were the best predictors of wind erosion rate. Meanwhile, MWD, surface gravel, clay content, and SOC had the best estimation for threshold velocity.