Influence of Shear Strength and Moisture Content on Aeolian Sand Erosion: Fid-Bau Portal

Influence of Shear Strength and Moisture Content on Aeolian Sand Erosion

Zambrano-Cruzatty, Luis / Yerro, Alba / Stark, Nina

Wind erosion is a critical factor in coastal engineering regarding its role in, e.g., coastal dune stability, dune morphology, and beach erosion. This phenomenon has been studied for decades from different research fields such as sedimentology, morphology, agriculture, or coastal engineering, resulting in different approaches to determine the wind velocity threshold required for particle mobilization. However, geotechnical parameters such as bulk density, friction angle, or the soil water characteristic curve (SWCC) have not been considered in these expressions, which contributes to uncertainties when predicting the fluid threshold velocity for a given sand using the existing predictive equations. This study proposes a new set of analytical expressions to estimate the initiation of wind erosion that includes the influence of the shear strength and moisture content. An infinite slope stability analysis has been performed in which the wind velocity effect is expressed as a set of normal and tangential stresses on the slope surface, and the shear strength of the sand is defined in terms of moisture content via the SWCC. The equations were calibrated and tested using a compiled dataset from the literature, which is composed of wind tunnel experiments performed on different types of uniform sands and water contents. Preliminary results show good agreement between the predicted and observed threshold velocities, which indicates that the erosion initiation by wind can be predicted using geotechnical parameters.