NLDAS -2

FARM SCALE DATA

REGIONAL WATERSHED MODELING OBJECTIVES

THE SANTA FE RIVER BASIN

HYDROLOGICAL MODELING APPROACH

SURFACE WATER MODELING: SOIL AND WATER ASSESSMENT TOOL (SWAT)

GROUNDWATER MODELING: MODFLOW

North Florida SouthEast Georgia (NFSEG) Groundwater Flow Model

PRELIMINARY RESULTS: COUPLING

FUTURE WORK

ACKNOWLEDGEMENTS

HYDROLOGICAL MODELING OF THE SANTA FE RIVER BASIN: TWO STAR-CROSSED MODELS

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1 - 1.5 mm2 meter Digital Elevation Model NLCD Land Cover SSURGO Soils

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Figure 1: Location of the Santa Fe River basin and subsequent nutrient loading sources and concentrations for springs and rivers.

Figure 2: Stratigraphic framework for principal aquifers within the basin boundaries. Image courtesy FDEP -www.floridadep.gov

Figure 3: Depiction of karst landscapes and processes. Image courtesy www.waltonoutdoors.com

UnconfinedConfined

Couple a surface and groundwater flow model using the Soil and Water Assessment Tool (SWAT) and MODFLOW

The SWAT model enables us to

• Assess different weather/climate scenarios

• Evaluate alternative land use/water management practices

• Simulate surface water quality

• Quantify nutrient leaching to the aquifer

• Estimate changes in stream discharge over time

Figure 6: MODFLOW Grid showing river cells and discretization

Precipitation

Temperature

Relative Humidity

Solar Radiation

Wind Speed

FOREST SCALE DATA

Weather/Climate Scenarios

Management Practices

Land Cover Changes

The MODFLOW-RT3D model enables us to:

• Capture the heterogeneity of the geologic system• 7 layers• Highly variable permeability

• Simulate water and nitrate exchange between river and aquifer

• Predict groundwater levels and nitrate concentrations through time in different layers

• Surficial Aquifer • Intermediate Aquifer System• Floridan Aquifer System (FAS)

• Springs and rivers

• Developed by the St. Johns Water Management District (SJWMD) and Suwannee River Water Management District (SRWMD)

• Simulates regional groundwater flow for the extent of the FAS in order to assess the impacts of water resource management decisions (Pumping, MFL’s)

Clipping the NFSEG model

Figure 10: Particle tracking to establish groundwater flow boundaries into the Santa Fe River basin

Figure 11: Results of the groundwater flow boundaries which out SWAT model domain was clipped to match as well

Figure 9: Boundaries of the NFSEG (dark outline) and the location of our clipped model

Figure 7: Vertical layering of each of the 7 stratigraphic units

Figure 8: Groundwater levels from Floridan Aquifer System (layer 3)

Generates

Figure 4: SWAT-MODFLOW hydrological tasks. Image courtesy of www.floridanwater.org

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Figure 12: SWAT-MODFLOW Framework in the context of the Santa Fe River Basin

Figure 15: Surface and groundwater exchange for select sites on the confined (A) and unconfined (B)

Figure 14: Observed and simulated (monthly) discharge at 02320700 gaging station.

Figure 13: Difference between average recharge for the year (2009) simulated in SWAT-MODFLOW and NFSEG

PHASE I

PHASE II

• Model has been coupled and data generated

• Continue calibration and validation of coupled model

Patricia Spellman1, David Kaplan1, and Wendy Graham21Environmental Engineering Sciences Department, Agricultural and Biological Engineering Department and UF Water Institute

Low : -1.94394

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Low : -1.94394

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• Couple a surface and groundwater model to adequately represent the unique hydrology of the Santa Fe River basin (Phase I)

• To quantify how changing climate, land use and management practices impact water quality and quantity, and to assess tradeoffs among water quantity, quality, and economic sustainability (Phase II)

m

I would like to thank my colleagues, SagarithaRath and Rob de Rooj for additional insight andinformation on this work. I would also like tothank Ryan Bailey from Colorado State forunbounded generosity and help on the project.

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Figure 5: SWAT Model schematic showing inputs and sample outputs

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Nutrient contribution sources courtesy of Florida DEP BMAP Report. Estimates obtained via NSILT

USGS Gage: 2321500

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Image courtesy www.swat.tamu.edu

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https://en.wikipedia.org/wiki/Floridan_aquifer#/media/File:Generalized_cross_section_from_Marion_County,_Florida,_to_Collier_County,_Florida.pnghttps://en.wikipedia.org/wiki/Floridan_aquifer#/media/File:Generalized_cross_section_from_Marion_County,_Florida,_to_Collier_County,_Florida.png

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