Doctoral Dissertation Research: Creation and implementation of an early warning system for sand dune remobilization

Arizona State University, Scottsdale AZ

Investigators

Abstract

Approximately one-third of the global population lives in arid regions, where drought has been increasing in duration and intensity under modern climate change. Drought conditions have been connected to dune remobilization, which is the transition of a dune field from stable to active. Remobilization can have detrimental effects on those living in arid lands, including impacts on infrastructure, agriculture, and human health. To date, remobilization and its impact on surrounding communities has been noted in several studies from around the globe. While studies on dune remobilization exist, they often focus on dune fields after movement has begun. However, if remobilization can be detected in its early stages, it allows communities to engage in proactive dune management strategies rather than the reactive approaches being used in many places today. This doctoral dissertation project investigates sand dune remobilization to inform an early warning system for remobilization. First, a study of paleoclimate-dune interactions is undertaken to determine the climate required for modern remobilization. Sand dune formation, activity, and stabilization have often been correlated with changes in climate, so determining the climatic impact on sand dunes from the past can inform climate-dune interactions in the future. Second, connections between historical climate, drought, and vegetation change are established under the prediction that increased drought conditions will reduce vegetation. Vegetation is a landscape stabilizer, so tracking vegetation loss over time can provide an early warning of a soon-to-be remobilizing dune field. Lastly, dune color is presented as a proxy for the presence of sand grain coatings, which are comprised of iron and clay and act not only as a landscape stabilizer but also exhibit an orange-red color that can be observed using remotely sensed imagery. Research investigations will combine a suite of methods, including paleoenvironmental analyses, remote sensing, and scanning electron microscopy that have not yet been used together for dune remobilization studies. Research products and findings will inform an early warning system for dune remobilization in arid regions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.