A Review of the Effects of Surface Moisture Content on Aeolian Sand Transport

Over the past several decades, a number of studies have shown that intergranular cohesion associated with the presence of moisture significantly increases the critical shear velocity required to initiate motion in sand grains, and decreases transport rates. This paper examines currently available models of moisture effects and compares model predictions for several hypothetical situations. Model predictions exhibit considerable disagreement regarding the magnitude of moisture effects. For 0.27-mm sands, predicted increases in threshold shear velocity associated with a 1% moisture content ranged from about 8% to 148% of the expected dry threshold velocity, and with 4% moisture increased to 47%–206% of the dry value. Based on the predicted threshold shear velocities, the expected transport rates at a 1% moisture content under a 0.50 m s−1 shear velocity range from no transport to more than 100 kg m−1 hr−1.