Salinity Intrusion

A salinity transport model for Biscayne Bay, Florida was used to estimate salinity under scenarios of altered precipitation, increased temperature and ocean salinity, and sea level rise. Under the mildest scenario a 50% increase in baseline freshwater inputs is needed to maintain current bay salinities, rising to 300% under the worst case — suggesting current Everglades restoration efforts may be insufficient to even maintain present conditions.

An EFDC+ hydrodynamic model of the Mississippi Sound was used with Lagrangian particle tracking to hindcast the locations of bottlenose dolphin deaths during a 2019 unusual mortality event. Results indicate that most dolphins likely died west of their stranding locations, with simulated salinities well below five at their probable places of death — consistent with prolonged exposure to low-salinity waters following the opening of the Bonnet Carré Spillway.

A hydrodynamic model was applied to Florida Bay to determine whether doubling Taylor River flow, as currently planned, is adequate to meet salinity performance measures and protect the bay’s ecosystem. Rainfall — which supplies 45% of the bay’s freshwater — caused the largest salinity reduction, and the restoration target was achieved more than 70% of the time only for existing bay conditions, not future sea-level rise.

A three-dimensional EFDC+ Explorer model was implemented to analyze salt wedge intrusion in the Sinú River delta, Colombia, configured with dry- and wet-season field campaigns from 2021. The model showed river discharges above 319 m³/s prevent salt wedge intrusion, while critical low-discharge and sea level rise scenarios produced a maximum salt wedge reach of 7.40 km.

An EFDC+ hydrodynamic model was developed for the ungauged Mentor Marsh of Ohio to simulate salinity distribution in a wetland that interacts with Lake Erie through a backwater effect. Calibration and validation against monitoring station data were good, and scenario analysis showed lake level rise drives a significant decrease in marsh salinity near Lake Erie.

EFDC+ was applied to model the hydrodynamics of the Lower St. Johns River Estuary in Florida, analyzing the extent of salinity intrusion and its implications for aquatic habitat. Results showed salinity intrusion is primarily controlled by upstream flow, long-term open-ocean variations, and wind drag, with the habitat analysis establishing a baseline for evaluating future management scenarios.

A three-dimensional EFDC hydrodynamic and salinity model of Jacksonville Harbor was developed to evaluate the impact of deepening the St. Johns River navigation channel from 40 to 50 feet. Validated over a conservative six-year period (1996–2001) that included the river’s lowest three-year flow on record, the model assessed channel-deepening effects on water level, salinity, and water age — including cumulative 50-year impacts combined with the Mayport deepening, freshwater withdrawals, and future sea level rise.

A three-dimensional hydrodynamic model was applied to the Oujiang River estuary in China to investigate residual circulation and stratification patterns. The study examines how river discharge and tidal forcing interact to shape circulation in this estuarine system.

Explicitly links salinity modeling results to aquatic habitat decision-making, the exact use case this sub-category describes.