Overview
The Lower St. Johns River Estuary in Florida has experienced both urban and exurban development along its banks over many decades. The extent of salinity intrusion into the estuary is controlled by a combination of factors that may be altered through natural or anthropogenic forces. To better understand these controlling factors, the Environmental Fluid Dynamics Code Plus (EFDC+) was applied to model the hydrodynamics of the estuary.
Model Setup
The study covers the calibration and validation of the model, analysis of the extent of salinity intrusion, and application of habitat analysis using the EFDC_Explorer Modeling System (EEMS).
Key Findings
The results showed that the extent of salinity intrusion in the Lower St. Johns River estuary is primarily controlled through varying combinations of upstream flow, long-term variations in the open ocean, and wind drag. The results of the habitat analysis — concerning submerged aquatic vegetation and wetlands — constitute a baseline for comparison with alternative management and future change scenarios for the basin.