EAR-Climate: Global Survey of Multiscale River Mobility and its Response to Climate Change and Human Interference

河流天生就是移动的。流动性有各种形式和大小，从最小的沙洲的下游游行到大洪水后河道的大规模改道。目前尚不清楚这些河流流动性的多尺度如何应对持续的气候变化和人类活动（例如，水坝、森林砍伐），这严重破坏了世界各地河流的水和沉积物供应。这个研究小组将通过调查卫星档案中的多尺度河流流动性来解决这一知识缺口-近半个世纪的全球图像-使用最先进的图像处理。该项目将为本科生、一名研究生和一名博士后研究员提供跨学科培训的机会。它还将与现有项目合作，为代表性不足的群体提供K-12外展服务，并提供有价值的公共数据集，为我们不断变化的世界中河流沿着未来研究和管理提供信息。为了调查多尺度河流流动性，调查人员将利用两种最先进的图像处理技术。首先，单个银行和酒吧的小规模运动将被捕获使用粒子图像测速。第二，大规模的运动渠道改道，洪泛区改造，和其他过程将被捕获使用达到规模的像素为基础的方法。然后，研究人员将河流流动性结果与全球观测和泥沙和供水模型相结合，以检验两个具体假设：1）大规模河流流动的速度是由长期的水沙供应决定的; 2）小规模河岸运动的速度已经改变，以应对最近气候和人类引起的水和沉积物供应中断，具有取决于河流类型的某种程度的自然变化（例如，蜿蜒的、编织的）。这项工作将促进我们的理解和能力，比较分析河流的流动性在地球仪。这一奖项反映了NSF的法定使命，并已被认为是值得支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

Rivers are inherently mobile. Mobility comes in all shapes and sizes, from the downstream march of the smallest sandbar to the wholesale diversion of river channels after a major flood. It remains unclear how these multiple scales of river mobility are responding to ongoing climate change and human activities (e.g., dams, deforestation), which are drastically disrupting the water and sediment supplied to rivers worldwide. This team of investigators will tackle this knowledge gap by surveying multiscale river mobility in the satellite archive—nearly a half-century of global imagery—using state-of-the-art image processing. The project will provide opportunities for interdisciplinary training to undergraduate students, one graduate student, and one postdoctoral researcher. It will also provide K-12 outreach to underrepresented groups in partnership with existing programs, and deliver a valuable public dataset to inform future studies and management along rivers in our changing world.To survey multiscale river mobility, investigators will leverage two state-of-the-art image-processing techniques. First, the smaller-scale motion of individual banks and bars will be captured using particle image velocimetry. Second, the larger-scale motion of channel diversions, floodplain reworking, and other processes will be captured using reach-scale pixel-based methods. Then, investigators will couple river mobility results with global observations and models of sediment and water supply to test two specific hypotheses: 1) the pace of large-scale river mobility is set by the long-term supply of water and sediment; and 2) the pace of small-scale bank movements has changed in response to recent climate- and human-induced disruption in water and sediment supply, with some degree of natural variability that depends on river type (e.g., meandering, braided). This work will advance our understanding and ability to comparatively analyze river mobility across the globe.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.