Physical Sciences and Mathematics Commons^™

An Evaluation Of Modified Bed Load Sediment Transport Equations For Enhanced Sediment Transport Quantification In Steep Mountain Streams – Case Study Little Fountain Creek, Colorado Springs, Co., James Emerson Smith Iv

LSU Master's Theses

In mountainous regions, extreme floods occur every year, placing societies and infrastructures at risk. Communities rely on local, state, and federal agencies to emplace flood structures, perform flood risk assessments, and simulate catastrophic events. While, our ability to quantify and predict the movement of sediment in streams with low gradients is well developed (Bathurst, 1987), our ability to quantify and predict the movement of sediment along steep mountain streams (SMS) has not been developed to a similar degree (Yager, 2012; Schneider, 2016). To most effectively manage mountainous watersheds and understand the risk associated with flood events, scientists must better understand …

Analysis Of Fluvial Scroll Bar Development With Surface Wave Inversion: False River, Louisiana, Blake Odom

LSU Master's Theses

The development of ridge-and-swale scroll bar topography of meandering river point bars is not well understood. We hypothesize that scroll bars formed during lateral accretion by the landward migration of transverse bars. To explore this, we relate the scroll bar topography to the internal sedimentary structure. We acquire, invert, and interpolate three pseudo-2D shear wave velocity profiles in two regions of the False River point bar, a Mississippi river oxbow lake in Pointe Coupee Parish Louisiana. Prior studies provide electrical conductivity well logs and cores as well as SH seismic reflection images along the same seismic surveys. LiDAR elevation data …

Three-Dimensional Flow, Morphologic Change, And Sediment Deposition And Distribution Of Actively Evolving Neck Cutoffs Located On The White River, Arkansas, Derek Allen Richards

LSU Doctoral Dissertations

Neck cutoffs are important and prominent features of alluvial rivers yet detailed field-based research of neck cutoffs has been insufficient to fully characterize three-dimensional flow, morphologic change, and sediment deposition and distribution. The main objectives of this research are to examine the formation and evolution of neck cutoffs by characterizing the flow field, morphology, and sediment distribution through neck cutoffs with complex planform configurations located on the White River, Arkansas. Results led to the production of two conceptual models. The flow model has main hydrodynamic characteristics of (1) tight bend flow resulting from flow redirection of nearly 180° through the …

Effects Of Natural And Anthropogenic Forcing On Marsh Channel Evolution, Jeremiah Robinson

LSU Master's Theses

Wetlands have many ecological and physical properties that are essential for coastal communities. These ecosystems sustain local economies, provide essential habitats, are a source of numerous ecological and biological services, and protect coastal populations from storms. Of the many wetland types, salt marshes are among the most vulnerable to environmental changes. Salt marshes quickly respond to natural and human-driven perturbations and their high rate of loss in the last century is cause for concern.

In this project the rate of marsh loss driven by channel widening was measured through a comparative analysis of modern high resolution images and historic aerial …

Topographic Control On Post-Lgm Groundings Of The West Antarctic Ice Sheet In The Whales Deep Basin, Eastern Ross Sea, Matthew Danielson

LSU Master's Theses

By the peak of the Last Glacial Maximum (LGM), the West Antarctic Ice Sheet (WAIS) had advanced to the outer continental shelf of eastern Ross Sea trough basins. During the post-LGM retreat, the WAIS paused several times within 75 km of the Whales Deep Basin (WDB) shelf edge. An overlapping stack of seven grounding zone wedges (GZWs) records the locations of these groundings. Here we used ~7500 km of seismic reflection data to map the subglacial unconformity that was eroded when WAIS was grounded at the shelf edge, i.e., prior to the deposition of the backstepping GZWs. With respect to …

Sediment And Plant Dynamics In A Degrading Coastal Louisiana Landscape, Glenn Michael. Suir

LSU Doctoral Dissertations

Alterations to Louisiana’s river systems and local hydrology have resulted in reduced freshwater, sediment, and nutrient inputs into wetland landscapes, causing significant negative impacts on marsh productivity and stability. To combat these losses many restoration projects have been constructed or planned throughout coastal Louisiana. Typical goals of wetland restoration efforts are to conserve, create, or enhance wetland form, and to achieve wetland function that approaches natural conditions. Failure to adequately maintain wetland elevation and hydrology can have serious implications on sedimentation and vegetation processes, which significantly reduces the likelihood of reaching structural and functional targets. Measures of wetland condition have …