3d_0320_zarillo_ppthhh
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Sediment Transport Modeling off the Northeast Coast of Florida
Gary A. Zarillo Florida Institute of Technology and Scientific Environmental Applications, Inc., Melbourne, FL
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Florida Inner Continental Shelf Study Areas
NE FL Shelf
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Geology of Shelf Sand Ridges
Origin and Dynamics
Numerical Modeling
• Strategy
• Applications
• Results
Combining Geological and Numerical Models to Assess the Impacts of Mining Sand Resources on the
Inner Continental Shelf of Northeast Florida
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Cretaceous Shannon Sandstone – Powder River Basin, WY
Cross-Bedded Shallow Water Sandstones
(Higley et al. 1997)
Geology of Shelf Sand Ridges
From Tillman 1985 4
Wave-Generated Bedforms at 12 m: A8 Shoal NE FL
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Sand Ridges in the Rock Record Mesozoic- Cenozoic Stratigraphy
From USGS 6
Oil Production from Ridge Sandstones
From USGS
Sussex B Sandstone
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Modern – Ancient Analogues
Cretaceous Period Sand Ridge A6 Sand Ridge NE Florida Continental Shelf
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Transgressive Sand Ridge Deposits – Fox Hills Sandstone
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Cross-bedded Storm Unit – Fox Hills Sandstone
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Modern Sand Ridge : A6 NE Florida Ancient Sand Ridge
See Tillman 1985; Rine et. al. 1991 for shelf sand ridge geology
Geology of Modern Shelf Sand Ridges
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Sand Ridge Origin in a Transgressive Barrier Island Setting
McBride and Moslow 1991 12
McBride and Moslow 1991
Shelf Sand Ridges – Florida Examples
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Indian River Shoal off East Central Florida Inner Continental Shelf
Beach Sand Borrow Area
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Sand Ridges/Linear Shoals of the NE FL Study Area
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Perspective Views of NE FL Shoals B11/B12
Shoals B12 and B11
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Model Grid Boundaries
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Spectral Wind-Wave Transformation Model CMS-WAVE Based on a spectral wave energy conservation equation: Considers wind input, shoaling, refraction, diffraction, and dissipation wave-current interaction
Circulation Model – CMS-FLOW Two-dimensional, finite-volume numerical solution of the depth-integrated continuity and momentum equations: Considers wave-current interaction, advection - diffusion, nonlinear continuity terms, forcing by water level, tidal constituents, flow-rate, wave stresses, and wind
Sand Transport Model – “LUND” Formulation Considers bed load, suspended load, wave-current interaction, initiation of motion, slope effects, and asymmetric wave velocity
The Numerical Models: USACOE/ERDC Coastal Modeling System
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Coastal Modeling System
http://cirp.usace.army.mil/products/index.html
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Model Setup
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- -
Tides
Wave Spectra
Water Level/ Winds
Model Setup – Boundary Time Series
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Storm-Related Wave Events
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12/11/97 3/21/98 6/29/98 10/7/98 1/15/99 4/25/99 8/3/99 11/11/99
Date
Hsi
g, m
0
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4
6
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Per
iod,
s
Significnt Wave Height, mPeak Period, s
Maximum Wave Event
Significant Wave Height, m
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Wave Model Calibration: NE Florida
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Measure v
Measured vs. Model Wave Period
Measured vs. Model Wave Direction
Wave Model
Calibration for
NE Florida
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• Time advancing runs of 2 years
• Event scale predictions for storm conditions
• Model predictions with/without borrow cuts
• Test single & multiple cuts from potential borrow areas
• Examine potential for modification of sediment transport
Numerical Modeling Strategy
ERDC/CHL Coastal Modeling System Coupled Wave and Circulation Models
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Model Test Location Borrow Cut Volume (m3) Duration Case1 B11_B12 Shoals None 0 2 years
Case 2 B11_B12 Shoals Single 600,000 2 years
Case 3 B11/B12 Shoals Multiple 8 million 2 years Case 4 A9 Shoal None 0 2 years
Case 5 A9 Shoal Single 1.2 million 2 years
Case 6 A9 Shoal Multiple 6 million 2 years
Case 7 A8 Shoal None 0 2 years
Case 8 A8 Shoal Single 1.2 million 2 years
Case 9 A8 Shoal Multiple 9.3 million 2 years
Case 10 A4-A6 Shoals None 0 2 years
Case 11 A4-A6 Shoals Single 2.8 million 2 years
Case 12 A4-A6 Shoals Multiple 18 million 2 years
Summary of NE Florida Model Test Cases
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B11-B12 Model Test Case 3
B11 B12
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Existing vs. Borrow Cuts: Hurricane Waves
Predicted Difference in Wave Height
B11
B12
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Event Scale Topographic Change
Deposition: Lower Shoreface
Erosion: Upper Shoreface
Deposition Lower Shoreface
Hurricane Floyd 1999 29
Model Predictions in the Littoral Environment
Numerical Recording Stations
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Predicted Annualized Net Littoral Sand Transport
Negative values indicate south-directed littoral sand transport 31
Predicted Difference Annualized Net Sand Transport in the Littoral Zone
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Shoal A6: Model Test Case 12
Federal Limit
Shoreline
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Predicted Event Scale Sand Transport
St. Augustine Inlet
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A6 Shoal Crest
Predicted Topographic Change – 24 Months at Shoal A6 (Predicted Topographic Change Over Ridge Crest +/-1 m)
No Sand Borrow Excavations
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Predicted Morphologic Change over Borrow Excavations (24-month model run A6 Shoal NE Florida Shelf)
Borrow Excavation
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Predicted Annualized Net Littoral Sand Transport A4 – A6 Shoals
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Predicted Difference: A4 – A6 Shoals Annualized Net Sand Transport in the Littoral Zone
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• Sand Ridges of NE Florida Continental Shelf are consistent with the sand geological model having clean sand units at the crest reworked and maintained by storms • Influence of the borrow cuts is at the event scale due to passing storms and associated long period waves • Along the NE Florida shoreline the influence of large borrow cuts is detectable but small compared to the annual sand budget and natural variability
Major Conclusions from the Model Simulations
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Acknowledgments
BOEMRE
U.S. Geological Survey
Florida Geologic Survey
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Higley D.K., M.P. Pantea and R.M. Slatt. 1997. 3-D Reservoir Characterization of the House Creek Oil Field, Powder River Basin, Wyoming, V1.00. U.S. Geological Survey Digital Data Series DDS-33.
McBride, R.A. and T.F. Moslow. 1991. Origin, evolution, and distribution of
shoreface sand ridges, Atlantic inner shelf, U.S.A. Marine Geology 97:57–85.
Rine, J.M., R.W. Tillman, S.J. Culver, and D.J.P. Swift. 1991. Generation of
late Holocene sand ridges on the middle continental shelf of New Jersey, USA – Evidence of formation in a mid-shelf setting based on comparisons with a nearshore ridge. International Association of Sedimentologists, Special Publication No. 14, pp. 395–423.
Tillman, R.W. 1985. A spectrum of shelf sands and sandstones. In: Tillman,
R.W., D. Swift, and R. Walker, eds. Shelf Sand and Sandstone Reservoirs. SEPM Short Course 13:1–46.
References
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