Marine Ecosystem Dynamics Modeling Laboratory

Research Ogeechee River Estuaries

The Ogeechee River Estuary is fed by one of coastal Georgia’s five major river systems characterized by a series of barrier island complexes, tidal creeks, and extensive salt marshes. Two major black-water tributaries originating upstream in the piedmont, the Little Ogeechee River to the north and the Ogeechee River to the south, bring fresh water to the system. The estuary is a typical tidal-dominated dynamic system that is influenced significantlyby upstream freshwater discharge. The annual mean freshwater discharge between 1937-1997 was 66.3 m3/s (USGS Station 02202500). Driven by strong tidal flow, the two major tributaries show good vertical mixing throughout the year. SatillaRiverSlideShow

In recent decades both natural environmental perturbations and human development activities have dramatically changed the Ogeechee River estuarine system. The development and implementation of successful strategies for maintaining, rebuilding or providing long-term management of estuarine resources requires scientists and managers to understand the natural variations and underlying mechanisms controlling complex estuarine ecosystems. Because this system is characterized primarily by the nonlinear interaction of physical, biological, chemical, and sedimentation processes and varies significantly with time and space, field measurements taken either at a give time or at a few monitoring stations do not provide sufficient information to either characterize or model the marsh and estuarine systems. It is imperative to develop a full three-dimensional, prognostic numerical model system if researchers are to understand this complex ecosystem. Managers need a scientifically accurate visual tool that will help them make strategic decisions on the proposed utilization of limited marine and coastal resources.

The Ogeechee River Estuary model system is being built on The Marine Ecosystem Dynamics Modeling Laboratory at the School of Marine Science and Technology, University of Massachusetts-Dartmouth (Marine Dynamics Laboratory) accomplishments in the development of an unstructured grid, finite-volume coastal ocean model (so called FVCOM). This system includes 1) a meso-scale meteorological model (called modified MM5) used to forecast and hindcast local weather ; 2) an FVCOM-based hydrodynamic model covering the Ogeechee River Estuary; 3) mass-conservative tracer and Lagrangian particle trajectory models used to track point or non-point source pollutants; 4) a real-time tidal forecasting and hindcasting model; and 5) a GUI interface software package that allows managers and scientists to use the model for coastal management and environmental assessment. This model system is designed to provide a scientifically sound-decision-making tool to the State of Georgia.

This research is supported by the Georgia Department of Natural Resources and led by Dr. Changsheng Chen, Professor at University of Massachusetts-Dartmouth (UMASSD) and Dr. Randy Walker, the Marine Extension Service at the University of Georgia (UGA). Participants includes Mr. Keith Gates at the UGA Marine Extension Service in Brunswick, GA and Dr. Jianhua Qi and Ms. Huichan Lin with the supports of Dr. Chen and Dr. Walker’s Georgia DNR research grants at the UGA Marine Extension Service.

Posted on January 14, 2014