Water Resources Research Act Program

Details for Project ID 2014GA344B

The effect of salt marsh hydrodynamics on estuarine flow

Institute: Georgia
Year Established: 2014 Start Date: 2014-03-01 End Date: 2015-02-28
Total Federal Funds: $18,000 Total Non-Federal Funds: $36,000

Principal Investigators: Kevin Haas, Donald Webster

Abstract: Georgia’s salt marshes are one of the most valuable and productive ecosystems in the state. Both the livelihood and benefits of salt marshes depend on the hydrodynamics across the tidal marshes and enclosed estuaries. A previous numerical modeling study has shown a strong linkage between the flow in Georgia salt marshes and the accompanying estuarine flow. The study demonstrated that both the intertidal storage and the enhanced marsh friction from the vegetation significantly alter the asymmetry of the estuary flow; however, the particular effects are highly dependent upon the details of the marsh flow, in particular the lateral extent of tidal flat flooding. Therefore it is essential to understand the relative timing and extent of the flow within the marsh and how this relates to the estuarine flow and asymmetry. The proposed project will begin to define such unknown details of marsh hydrodynamics through simultaneous field measurements of estuarine and marsh flow across a transect. This project will leverage a planned field experiment which already includes detailed measurements of velocities and turbulence in and around oyster reefs in coastal Georgia. We will supplement these experiments with simultaneous additional marsh water level measurements, velocity profile measurements near the oyster bed, and transect measurements of the currents and water level across the main channel. The specific project objectives are as follows: 1) Obtain comprehensive synchronized water level and velocity field measurements in a Georgia salt marsh and corresponding main flow channel. 2) Analyze the data obtained in the field project to determine the relationship between the peak flows in the channel and the marsh inundation and compare this with the relationships determined by the previous numerical model simulations.