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

全球约有三分之一的人口生活在干旱地区，在现代气候变化的影响下，干旱的持续时间和强度都在增加。干旱条件与沙丘再活动有关，沙丘再活动是沙丘从稳定到活跃的过渡。重新流动可能对生活在干旱地区的人产生有害影响，包括对基础设施、农业和人类健康的影响。迄今为止，地球仪的几项研究已经注意到重新动员及其对周围社区的影响。虽然有关于沙丘再运动的研究，但它们往往集中在运动开始后的沙丘区。然而，如果能够在早期阶段发现重新动员，社区就可以采取积极主动的沙丘管理战略，而不是采取目前许多地方所采用的被动办法。本博士论文项目调查沙丘再动员，通知再动员预警系统。首先，进行古气候沙丘相互作用的研究，以确定现代再动员所需的气候。沙丘的形成、活动和稳定往往与气候变化相关，因此确定过去气候对沙丘的影响可以为未来的气候-沙丘相互作用提供信息。第二，历史气候，干旱和植被变化之间的联系建立在预测的干旱条件增加将减少植被。植被是一种景观稳定剂，因此，随着时间的推移，跟踪植被损失可以提供一个即将重新激活沙丘领域的早期预警。最后，沙丘的颜色是作为一个代理存在的沙粒涂层，这是由铁和粘土，不仅作为一个景观稳定剂，但也表现出橙红色，可以观察到使用遥感图像。研究调查将结合联合收割机的一套方法，包括古环境分析，遥感和扫描电子显微镜，尚未一起用于沙丘再活化研究。研究成果和发现将为干旱地区沙丘再活化的早期预警系统提供信息。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.