While the Department of River-Coastal Science and Engineering at Tulane is in its formative stages, there are opportunities for graduate-level students to work with our faculty in several different ways. The tenure-track faculty (e.g., Allison and Meselhe) are seeking graduate students that can be tracked through the Earth & Environmental Sciences (M.S. and PhD) degrees, or through the SSE Interdisciplinary PhD program. There are also research opportunities for graduate-level students to work with our other faculty through the RCSE6900 Independent Study course, or through internships with our U.S. Army Corps of Engineers adjunct faculty. Prospective students should inquire with individual faculty about specific opportunities in their fields of interest. A brief introduction to these interests is listed below for each of our faculty:
River and Coastal Sediment Dynamics and Radiochemical Lab
Team: Graduate students Katrina Ginsburg, Marie Mathews, Autumn Murray, Ryder Myers,
Undergraduate research assistants Madeline Case, Genevieve Messa, McKenna Price-Patak
Our projects are linked to both basic and applied science associated with the river-delta-coast continuum, particularly large rivers worldwide. Past research has been conducted in the Amazon, Mississippi, Ganges-Brahmaputra, Changjiang (Yangtze), Mekong, Fraser, and Arctic rivers. Our basic research is designed to develop a better process understanding of the flow of water and sediment through these systems and their geologic evolution over the late Holocene sea level maximum. Our applied work is associated with the protection and restoration of the Mississippi and the Mekong deltas, including (1) examining the utility and methodology of large river diversions for rebuilding coastal wetlands by harnessing the crevasse splay methodology of natural river evolution, (2) examining river bar evolution and its links to the utilization of sand resources via long-distance pipeline conveyance to build wetlands and restore barrier islands, (3) testing the efficacy of various restoration strategies including the use of green infrastructure to alter morphology of the coastal realm for protecting human and natural resources, and (4) examining the impact of episodic events such as large floods and hurricanes on system evolution and health. We utilize a wide range of tools to address these issues including multibeam bathymetry/LIDAR, subbottom and side-scan sonar mapping, InSAR subsidence remote sensing, sediment coring, water quality sampling, fixed water and sediment dynamics platforms. Many of our field and laboratory activities are conducted at the Tulane River and Coastal Center operated by Tulane’s Bywater Institute. We also operate a radiochemical geochronology laboratory on the uptown campus featuring a variety of alpha and gamma spectrometers that allow us to measure key radiotracers in the natural environment.
My primary research goals are focused on the development of improved guidance for incorporating the concepts of fluvial geomorphology, channel stability and regional sediment management into the design of river engineering and channel restoration projects. Much of research has been directed at the development of improved designs for river engineering structures such as bank stabilization, training structures, and grade control structures. Not only are better and more innovative designs needed for these structures, but there is also a critical need to improve our understanding of how these structures weave into the overall morphological character of the river system. This is particularly true for the design of channel restoration projects. All too often restoration projects fail to meet project goals because the basic geomorphic principals of channel stability and sediment continuity have been inadequately addressed, or in many cases ignored completely. Additionally, many river engineering and restoration projects are designed to meet localized goals, but fail to address how the project will work within the broader channel system. In recent years, the concept of applying a regional sediment management approach to river engineering design has grown in acceptance. Unfortunately, design guidance for these type of basin-wide studies is severely lacking. Another area that I am actively engaged in is the development of a geomorphic model that is capable of modeling complex geomorphic trends over long time periods (50 to 200 years), capturing the uncertainties in natural river behavior, and treating outputs in a probabilistic manner.
Coastal hydrodynamics, morphodynamics and hurricane impacts
My research is focused on hydrodynamic and morphodynamic processes and hurricane impacts (e.g. winds, storm surge and waves) in estuarine and coastal areas. In the past years, I conducted projects for the areas of Yangtze estuary and Hangzhou bay in China, Mobile bay and coastal Louisiana in the Northern Gulf of Mexica, and Delaware bay and Jamaica bay in the east coast of US. My research experience includes development of a computer modeling system to predict storm surges (ADCIRC/Delft3D), hurricane waves (SWAN), and corresponding wetland erosion and sedimentation (Delft3D) under unstructured meshes and curvilinear grids for gulf-scale and regional applications; improvement of a parametric hurricane wind model based on the asymmetric Holland-type vortex models; analysis of directional spectra of hurricane-generated waves in the Gulf of Mexico; numerical study of vegetation impact on reducing storm surge by wetlands; numerical modeling of salt marsh morphological change induced by Hurricane Sandy. Currently, our areas of interest are Mississippi River Delta and Louisiana coasts. We take coastal models (e.g., Delft3D and SWAN) as a tool to numerically study temporal and spatial variations of water level, current, waves, salinity, temperature, sediment transport and water qualities; short-term and long-term morphological changes; impacts of extreme events such as flood, storm surge and hurricane waves; impacts of human activities such as sediment diversion projects, navigation channel dredging and hydraulic structures.
Tulane and U.S. Army Corps of Engineers (Engineering Research and Development Center, Vicksburg, MS)
My research is centered around the Mississippi River and tributaries, but as part of a research Team with the U. S. Army Corps of Engineers, we have worked across the United States on most navigable waterways and several coastal environments. Most research is applied to ongoing water resource projects with the goal of predicting biological responses of aquatic organisms to changes in the environment due to navigation, flood control, of ecosystem restoration activities. Improving or conserving biotic integrity is our primary goal, and therefore we need to fully understand the diversity of species utilizing our waterways. In order to properly sample different types of river systems, we use multiple collecting gears for fish (trotlines, trawls, hoopnets, gillnets, seines), aquatic insects (nets, dredges, benthic sleds), and freshwater mussels (benthic sled, divers, pollywog). These gears are used to sample endangered and invasive species, as well as determining overall assemblage structure. We have specialized instruments to quantify the habitat conditions at each collecting site including water quality, hydraulic variables, structural complexity, and a strong GIS component. Since USACE manages all of the navigable rivers and many tributaries for flood control or hydroelectric purposes, the type of problems encountered is challenging and sometimes unusual. For example, we have determined the species composition and number of fish species entrained by towboat propellers using a specially-designed net affixed to the stern of the boat. Rescue of endangered sturgeon entrained through floodways, such as the Bonnet Carre Spillway, has been ongoing due to increased flooding in the Mississippi River. Quantifying swimming speeds and jumping capability of the highly invasive Silver Carp was conducted in laboratory and field studies to determine feasibility of hydraulic barriers. Similarly, we have subjected Asian Carp to electric barriers and provided operating parameters to operate these types of barriers in navigable waterways. We depend on an interdisciplinary team with strong backgrounds in aquatic ecology and field biology to collect data objectively, and an ability to statistically analyze the data and publish the results to satisfy sponsor and funding requirements.
River and Riverine Floodplain Ecology and Biogeochemistry
My projects are focused on linking biotic components of the riverine environment to the geology, hydrology and chemistry of the river system and conveying this information to river managers. Although my research has been conducted across the United States, it has been focused on the tributaries, adjacent bottomland hardwoods, and the main stem of the Mississippi River. My research is centered around three main themes: 1) the measurement of sediment deposition in bottomland hardwoods wetlands and the measurement of suspended sediments in river systems, with an eye towards the ability of wetlands to improve river water quality; 2) the water quality of river systems in the lower Mississippi valley, including nutrients and agricultural chemicals and and their relationship to land use; 3) and the development of an improved understanding of how the hydrology, sediment transport and water chemistry of the Mississippi River influences the delta and the coastal wetlands of the river as it enters the Gulf of Mexico and how this knowledge can be used to guide restoration efforts.
In addition to these science topics, my career has involved some very applied topics such as the enforcement of environmental laws, wetland delineation, evaluation and regulation, and the generation of materials for feasibility studies and environmental impact statements. These experiences have reinforced my conviction that the effective communication of scientific information to water resources managers and non-scientists is an essential part of quality science and scientific education.
Development and application of numerical models to rivers, watersheds and coastal areas; development of operational and forecast models; planning and analysis of large-scale ecosystem programs; participatory modeling (with community members) ; coastal and deltaic morphodynamic analysis.
My work focuses on empirical modeling of biotic-abiotic relationships in two main research areas: 1) assessment and optimization of ecological services provided by large river-floodplain connectivity; and 2) evaluation and restoration of habitat in streams with long-term anthropogenic impacts. As such, I have devoted much time and energy to understanding the stochastic processes that influence these metrics and the uncertainty associated with quantifying them. Large-scale ecological datasets often require complex experimental designs and specialized analytical tools to reveal underlying relationships and handle multiple sources of variability. I am especially interested in the translation of these findings into best management practices and the effective communication of both recommendations and caveats to stakeholders and planners. These are of great importance within the arenas of natural resource monitoring and adaptive management. Most of my data collections have occurred within the alluvial valley of the Mississippi River and its tributaries, as well as adjacent coastal river basins along the northern Gulf of Mexico.
Development and application of numerical models to system of systems simulations, large scale geophysical circulation, continental scale hydrology, compound flooding and computational fluid dynamics to study fluid-structure interactions.