Spatiotemporal Dynamics of Bedload Sediment Flux in Large Rivers

地理学空间科学（GSS）计划该研究项目将提供有关全球尺度的预测和分析在大型河流泥沙通量的新知识，特别注意到在河床中的泥沙输运。 研究人员将开发一个全球分布的推移质通量计算机模型，以分析推移质与环境动态之间的空间相互作用以及推移质与悬浮泥沙之间的比例。 该项目将为河流地貌的驱动因素和机制提供新的见解，从而改变对这些关键地貌过程的基本分析能力。 该项目将纳入一个多方面的教育计划，通过研究、指导和涉及研究生、本科生和中学生以及公众的外联活动，促进地理和地球科学的研究、教学和学生参与。 项目成果将通过在亚拉巴马自然历史博物馆举办长期解说展览，提高公众对水资源和教育的认识。推移质输移是河流系统物理、生物和化学动力学的重要驱动力，它影响河流系统的水质和可用性、河流形状和生态功能以及海岸动态。 研究人员将在现有的全球尺度水文建模框架内开发一个新的推移质通量模块。 分析将侧重于基于物理的推移质模块在大规模模拟中的普遍适用性，以及沿着系统悬浮物通量和推移质通量之间的比例的空间趋势及其与流域特征的关系。为了促进这些分析并验证模型，将从现有的美国地质调查局数据库，学术文献，在线资源和研究者的合作网络中收集全球分布的观测数据库。 这项研究的结果将提供一个第一个空间和时间上明确的一阶估计全球推移质通量和数值框架研究的参数，驱动程序和机制，在全球大型河流的推移质通量。 河流中沉积物迁移的量化将有助于研究碳和养分循环、河流、沿海和海洋生态、水坝的可持续性以及水和粮食安全。

NATIONAL SCIENCE FOUNDATIONGEOGRAPHY SPATIAL SCIENCES (GSS) PROGRAMABSTRACTThis research project will provide new knowledge regarding global-scale predictions and analysis of sediment fluxes in large rivers, with special attention given to sediment transported in riverbeds. The investigator will develop a globally distributed, bedload-flux computer model to analyze the spatial interactions between bedload and environmental dynamics as well as the ratio between bedload and sediment transported in suspension. The project will provide new insights into the drivers and mechanisms of fluvial geomorphology, thereby transforming fundamental analytical capabilities with regard to these key geomorphological processes. The project will incorporate a multifaceted educational plan that promotes research, teaching, and participation of students in geography and the geosciences through a combination of research, mentoring, and outreach activities involving graduate, undergraduate, and middle school students as well as the general public. Project results will enhance public awareness of water resources and education through a long-term interpretive exhibit at the Alabama Museum of Natural History. Bedload sediment transport is a significant driver of the physical, biological, and chemical dynamics in river systems, and it affects water quality and availability in river systems, river shape and ecological functioning, and coastal dynamics. The investigator will develop a new bedload flux module within an existing global-scale hydrological modeling framework. The analyses will focus on the universal applicability of the physically based bedload module for large-scale simulations and on the spatial trends of the ratio between suspended and bedload fluxes along river systems as well as its relationship to river basin characteristics. To facilitate these analyses and to validate the model, a globally distributed observational database will be collected from existing U.S. Geological Survey databases, scholarly literature, online resources, and the investigator's collaborative network. Outcomes from this research will provide one of the first spatially and temporally explicit first-order estimates of global bedload flux and a numerical framework for studying the parameters, drivers, and mechanisms of bedload flux in large global rivers. The quantification of sediment transport in rivers will be catalytic for examining carbon and nutrient cycles, river, coastal and marine ecology, dam sustainability, and water and food security.