Modeling the Mechanisms Behind Yardang Evolution

Abstract

New work by Pelletier et al. (2018, https://doi.org/10.1002/2017JF004461) and Pelletier (2018, https://doi.org/10.1002/2017JF004462) quantitatively explains how arid landscapes can be sculpted into regular “teardrop”-shaped hills known as yardangs. A diversity of theories have been proposed to explain these perplexing hills. Pelletier (2018) helpfully clarifies that the most likely suite of mechanisms involves an interplay between wind- and water-driven erosion. Using detailed field measurements from Ocotillo Wells, California, a model is developed that explains how yardangs achieve their characteristic form and spacing. Although couched around the iconic yardang, the work contributes a general and robust template for understanding landscapes where both wind and water erosion are present.