Predicting Coastal Deltaic Change on a Global Scale

海岸侵蚀预计将成为21世纪世纪地球表面的主要危害，部分原因是海平面上升、河流筑坝和土地利用变化将影响河流三角洲的沉积物收支。沿海变化预测对于长期沿海管理和未来沿海灾害评估，特别是与气候变化有关的沿海灾害评估至关重要。这个项目将突出三角洲在哪里以及以多快的速度被海平面上升淹没，被海浪侵蚀成沙嘴和堰洲岛，或者被潮汐塑造成冲积河口。这样一个统一的全球图景也可以用来评估由碳排放等因素驱动的不确定的未来情景将如何影响沿海变化。为了产生更广泛的影响，调查人员将与Delaware和联合国合作，通过开发三角洲预测工具，在地方和全球范围内接触决策者，这是一个新的互动式网络地图，将突出显示河流三角洲的预测变化。这一工具将与联合国大学出版的关于未来三角洲变化的白色文件一起使用。所有模型代码和数据将在一个公共存放处向科学界提供。这项研究将支持一名博士后研究员，一名研究生和一名本科生。该项目将建立国际和跨学科合作。当河流的沉积物沉积在河口附近时，就形成了河流三角洲。三角洲存在于各种各样的形状和大小，部分原因是海浪，潮汐和海平面波动移动海岸带内的沉积物。这种可变性使得预测河流三角洲周围未来的海岸侵蚀和沉积具有挑战性。该项目将建立一个全球河流三角洲变化的计算机模型，以便：（i）通过计算由于河流、海浪、潮汐和海平面波动引起的沉积物运动来预测现代河流三角洲的形状，以及（ii），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。

Coastal erosion is expected to be a major Earth-surface hazard in the 21st century, in part because sea-level rise, river damming, and land-use changes will affect the sediment budget of river deltas. Predictions of coastal change are critical for both long-term coastal management and the assessment of future coastal hazards, particularly in relation to climate change. This project will highlight where and how fast deltas are expected to be drowned by sea-level rise, eroded by waves into spits and barrier islands, or shaped by tides into alluvial estuaries. Such a unified, global picture can also be used to assess how uncertain future scenarios, driven by for example carbon emissions, will affect coastal change. To achieve broader impacts the investigators will collaborate with Deltares and the United Nations to reach decision makers on a local and global scale by developing the Delta Forecast tool, a new interactive web-based map that will highlight projected changes to river deltas. This tool will accompany a white paper on future deltaic change published with the United Nations University. All model codes and data will be made available to the scientific community in a public repository. This research will support one postdoctoral researcher, one graduate student, and one undergraduate student. The project will set up international and interdisciplinary collaborations. River deltas form when sediments from a river are deposited close to the river mouth. Deltas exist in a wide variety of shapes and sizes partly because ocean waves, tides, and sea-level fluctuations move sediments within the coastal zone. This variability has made it challenging to predict future coastal erosion and deposition around river deltas. This project will create a global computer model of river delta change to: (i) predict modern river delta shape by calculating sediment movement due to the river, ocean waves, tides, and sea-level fluctuations, and to (ii), incorporate predictions of changes to these forces and assess future river delta change.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.