Predicting Coastal Deltaic Change on a Global Scale

海岸侵蚀预计将是21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泥沙收支。对沿海变化的预测对于长期的沿海管理和评估未来的沿海危害，特别是与气候变化有关的危害，都是至关重要的。该项目将突出三角洲预计将在哪里以及以多快的速度被海平面上升淹没，被海浪侵蚀成唾液和障碍岛，或被潮汐塑造成冲积河口。这种统一的全球图景也可以用来评估不确定的未来情景，例如由碳排放驱动的情况，将如何影响沿海变化。为了实现更广泛的影响，调查人员将与Deltares和联合国合作，通过开发Delta Forecast工具，在当地和全球范围内接触决策者，这是一种新的基于网络的互动地图，将突出河流三角洲的预测变化。该工具将与联合国大学一起出版一份关于未来三角洲变化的白皮书。所有模型代码和数据都将在一个公共储存库中向科学界提供。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。当河流中的沉积物沉积在靠近河口的地方时，就形成了河流三角洲。三角洲以各种各样的形状和大小存在，部分原因是海浪、潮汐和海平面波动使海岸带内的沉积物运动。这种变异性使得预测未来河流三角洲周围的海岸侵蚀和沉积变得具有挑战性。该项目将创建一个河流三角洲变化的全球计算机模型，以：(I)通过计算河流、海浪、潮汐和海平面波动引起的泥沙运动来预测现代河流三角洲的形状，以及(Ii)纳入对这些力量的变化的预测，并评估未来的河流三角洲变化。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.