Marine Ecosystem Dynamics Modeling Laboratory

Flooding / Drying Process

Flooding / Drying Process

Coastal Georgia’s Ogeechee River Estuary is characterized by many tidal creeks, natural barriers, islands, and inter-tidal marshes. The diurnal 3-D tidal driven flooding/drying process is an essential physical mechanism driving estuarine water exchange encompassing the estuarine – tidal creek – salt marsh complex within the Ogeechee River Estuary. Using a mass conservative wet/dry point technique incorporated in FVCOM.

Flooding Tide

High tide

Ebb Tide

Low Tide

Fig.1 The simulated tidal flooding/drying process of the Ogeechee River Estuary. Click here to view the animation

We simulated the water transport into and out from the inter-tidal salt marsh. The results clearly show that this new technique not only provides more detailed structure of the water movement and transport over the estuarine-tidal creek-salt marsh complex but also captures a right physics of the flooding/drying processes in the Ogeechee River Estuary. A successful example can be seen in figures attached on this page, which shows the cover area of water overlapped with surface current vectors in one tidal cycle. When the water is advected into the estuary during flood tidal period, the water flows into tidal creeks and also flood over barriers and the salt marsh area. Most parts of the marsh area were covered by the water at the high water level. The water flows back to the main channel during the ebb tidal phase, and then restricted to the main channel and tidal creek at the low water level. At the spring tidal cycle, the water could cover the entire area bounded by the 2-m elevation lines.

This is the first innovative modeling accomplishment in the Ogeechee River Estuary, which has provided us a scientifically-sound tool to valuate the water exchange process in this estuary. This model also makes it possible to build a monitoring model system for the salinity and water quality.

Posted on January 16, 2014