EAR-PF: Field observations and modeling of backwater effects on bed material sequestration and fluvial kinematics in the lowermost Mississippi River

Jeffrey a . Nittrouer博士被授予美国国家科学基金会地球科学博士后奖学金，在伊利诺伊大学厄巴纳-香槟分校开展一项研究和教育计划。Nittrouer博士将使用密西西比河下游的实地观察研究，并结合物理模型来了解河流靠近其海洋出口的沉积物运输动力学。收集的数据包括低潮和高潮期间的水沙输运测量数据，这将有助于限制时空泥沙通量差异，以及与两种排水制度相关的输运应力。此外，对河床沉积物组成的测量和沉积物通量的时间将用于描述密西西比河最下游的河道形态和平台特征的测量变化的原因。这项研究将为沉积物和相关颗粒从蜿蜒河流系统到三角洲和海洋环境的时间和运动提供分析。这是一个特别重要的研究领域，因为当河流接近其出口时，水流减速对沉积物通过源-汇沉积体系的路径有重要影响。这些信息将直接应用于最近减轻路易斯安那州南部沿海湿地损失的努力。湿地是对环境敏感的系统，在许多生态服务中，它可以自然地缓冲威胁城市人口和基础设施的风暴潮。在主办机构对地球科学和河流系统动力学感兴趣的学生将接受培训，操作最先进的仪器和软件程序，从最下游的密西西比河收集和分析数据。此外，学生将学习河流流体动力学和泥沙运输背后的物理理论。将举行教育研讨会，讨论路易斯安那州南部丰富的河流和沿海湿地问题，随后将进行实地考察，追踪密西西比河，从中西部开始，在路易斯安那州的出口结束。

Dr. Jeffrey A. Nittrouer is awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the University of Illinois, Urbana-Champaign. Dr. Nittrouer will use field observation studies from the lower Mississippi River coupled with physical modeling to provide an understanding for sediment transport dynamics where a river nears its marine outlet. Data to be collected include measurements for water and sediment transport during low- and high-water discharge, which will help constrain spatial and temporal sediment flux disparity, and the transport stress associated with both water discharge regimes. Additionally, measurements for channel bed sediment composition and timing of sediment flux will be used to describe causes for measured changes in channel morphology and planform character of the lowermost Mississippi River.This research will provide analyses for the timing and movement of sediment and associated particulates from meandering fluvial systems to the deltaic and marine environment. This is a particularly important area of study, because decelerating water flow as a river nears its outlet has important influences for the routing of sediments through source-to-sink sedimentary systems. This information will have direct applications for recent efforts to mitigate coastal wetland loss in southern Louisiana. Wetlands are environmentally sensitive systems that, amongst many ecological services, naturally buffer storm surges that threaten urban populations and infrastructure.Students with interest in geoscience and river system dynamics at the host institution will be trained to operate state-of-the-art instruments and software programs that collect and analyze data from the lowermost Mississippi River. Additionally, students will be educated in the physical theory behind fluvial hydrodynamics and sediment transport. Educational seminars will be held to discuss river and coastal wetland issues that abound in southern Louisiana, and will be followed by a field trip that will trace the Mississippi River, starting from the Midwest and ending at its outlet in Louisiana.