Abrasion of soil clods with different textures and moisture contents in sand flow environment

Abstract

Abstract Abrasion is an important but complicated and fundamental process in soil wind erosion. To determine the relationship between the abrasion mass (AM) of soil clod and sand transport rate (q), and to investigate the influences of clod characteristics including moisture content, geometry, and soil texture on AM and on clod abrasion resistance, we conducted soil clod abrasion experiments in a wind tunnel. The soils types were aeolian sandy soil, loess soil, chestnut soil, and brown calcic soil, respectively. The abraders were the same soil as used for making the target clods. We found that moisture content obviously influenced AM, and the AM variation at relatively high friction velocity (u∗ = 0.44, 0.52, and 0.60 m∙s−1) showed different trends from those at lower u∗ (0.31 and 0.37 m∙s−1). For dry clods of each soil type, AM of the hexagonal prism clod was greater than that of cylindrical clod, but for moist clods, AM of the two geometries differed among soil types. We developed an AM prediction equation which mainly accounts for the mean particle size (d) and u∗. Using the abrasion coefficient (AC) as the abrasion resistance index, dry clods of the loess soil showed the strongest resistance, followed by clods of an aeolian sandy soil, chestnut soil, and brown calcic soil. However, AC could not quantitatively predict the resistance of moist clods.