Spatial Variability in Aeolian Abrasion

Wind-driven sediment transport dominates arid landscape evolution. In particular, wind-blown sand forms dune fields and erodes exposed surfaces through abrasion. Aeolian dunes often serve as a sand source for abrasion, however, the relationship between the magnitude of abrasion and distance from a sand source remains poorly constrained. Previous work on aeolian abrasion has focused on ventifacts, wind-carved cobbles and boulders that record the direction of erosive winds in their pattern of surface erosion. These geologic indicators provide robust evidence that wind-abrasion has occurred, but without more information provide little insight into the magnitude or rate of surface erosion. Aeolian abrasion can cause significant damage to both natural and engineered materials, but sometimes proximity to sand sources is unavoidable. A quantitative understanding of how aeolian erosion rates vary with material type and distance from a dune field would facilitate better-informed decision making in arid regions, and provide expected rates of degradation from aeolian abrasion that could be used in planning and risk management. The proposed work aims to address this gap in knowledge. We propose a12-month field experiment in which we monitor the wind conditions in the Ibex dune field, capture saltating sand causing abrasion, and measure progressive abrasion-related mass loss on a variety of natural and synthetic materials at increasing distance from the dunes. The proposed work is divided into three major tasks completed over a total of 18 months: Assembly of sampling devices and deployment of those devices in the field (Task 1a), contextual mapping of ventifacts in the study area (Task 1b), field monitoring of sediment flux and abrasion (Task 2),and finally data analysis (Task 3).