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

Nittrouer, Jeffrey A, Austin TX

Investigators

Abstract

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.