Simulation of Hydrodynamics and Simulation of Hydrodynamics and

Solute Transport in the Solute Transport in the

Suwannee River Estuary, FloridaSuwannee River Estuary, Florida

Jerad BalesJerad BalesU.S. Geological SurveyU.S. Geological Survey

Raleigh, NCRaleigh, NC

Study ObjectivesStudy Objectives• Characterize hydrologic

and salinity conditions in Suwannee River Estuary

• Develop, calibrate, and document 3-dimensional unsteady flow and salt transport model.

• Provide tool for further applications in Suwannee River Estuary and offshore.

Continuous Data Collection in EstuaryContinuous Data Collection in Estuary

FlowFlow SalinitySalinity Water Water LevelLevel

SalinitySalinityWater Water LevelLevel

3 km offshore3 km offshore

0.35 in 2000 compared to 0.45 in 1955

0.27 in 2000 compared to 0.25 in 1955

Flows During Data-Collection PeriodFlows During Data-Collection Period

Suwannee River Estuary Net FlowsSuwannee River Estuary Net Flows

Buoy #1 W4 G1River Fork

E6W1 W6 W7 W8WPWM

W5

7/27/00 10:40 – 11:33

Buoy #1 W4 G1River Fork

E6W1 W6 W7 W8WPWM

W5

7/27/00 18:35 – 19:54

Suwannee River Estuary Model:Suwannee River Estuary Model:A Salinity Prediction ToolA Salinity Prediction Tool

• How can the effects of changes in How can the effects of changes in river flow be separated from all of the river flow be separated from all of the other factors affecting salinity in the other factors affecting salinity in the Suwannee?Suwannee?DataData--no experiments --no experiments --natural variability is great--natural variability is great

Statistical techniquesStatistical techniques--many factors--many factors

Computer modelComputer model--captures most relevant--captures most relevant natural processes.natural processes.

Computational Grid and BoundariesComputational Grid and Boundaries

Upstream boundary: AGRMeasured flow, zero salinity

Ocean boundary: ~20 kmTides from Cedar Key, Salinity = 35 psuDepth = 8-9 meters

Tidal boundary: Cedar KeyTides from Cedar Key;Estimated constant salinity

Tidal boundary: Horseshoe Pt.Tides from Cedar Key;Estimated constant salinity

Some Results

Opportunities and NeedsOpportunities and Needs

• Opportunities with existing modelOpportunities with existing modelEvaluate effects of flow changes on salinity Evaluate effects of flow changes on salinity

distribution (time and space) in estuary and offshore.distribution (time and space) in estuary and offshore.Simulate movement of neutrally buoyant material Simulate movement of neutrally buoyant material

(perhaps larvae?)(perhaps larvae?)

• NeedsNeedsIncreased spatial resolution near shore, including Increased spatial resolution near shore, including

tidal creeks, marshes, and offshore reefs.tidal creeks, marshes, and offshore reefs.Ground water inputs.Ground water inputs.Better seaward salinity boundary conditionBetter seaward salinity boundary conditionNutrient transport.Nutrient transport.

For Additional InformationFor Additional Information

Jerad BalesU.S. Geological Surveyjdbales@usgs.gov

919-571-4048

Data CollectionData Collection

•StreamflowStreamflow•WindWind•Water LevelWater Level

•SalinitySalinity•VelocityVelocity•BathymetryBathymetry

Calculation of Net Freshwater Flow at East PassCalculation of Net Freshwater Flow at East Pass

FlowFlowdistributiodistributio

nnon falling on falling

tidetide

Flow Flow distributiodistributio

nnon rising on rising

tidetide

EFDC--Rationale for SelectionEFDC--Rationale for Selection

• Scientifically robust.Scientifically robust.

• Public domain--available to SRWMD.Public domain--available to SRWMD.

• Good documentation.Good documentation.

• Supported by EPA.Supported by EPA.

• Used successfully by SJRWMD and Used successfully by SJRWMD and SFWMD.SFWMD.

• Water-quality simulation capabilities.Water-quality simulation capabilities.