Ty Wamsley

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LACPR and MsCIP Regional System-wide
Analysis Storm Surge and Wave Modeling 84th
Meeting of the Coastal Engineering Research Board
Ty Wamsley USACE Engineer Research and
Development Center
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Modeling System

• IPET
• FEMA
• LaCPR
• MsCIP

TC96 PBL
Wind Field Wind Stresses
Surge Model
Wave Models
Coupling
Offcoast Waves WAM Nearshore Waves STWAVE
Unified Grid Surge model ADCIRC
Local Scale Waves Boussinesq - Parametric
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ADCIRC Grid Domain
LaCPR and MsCIP
WAM Model Domain
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STWAVE Model Domains
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Storms for JPM-OS

• Parameter Space
• Cp 900 to 960 mb
• Rmax 6 to 35.6 nm
• Vf 6 to 17 knots

LaCPR MsCIP MsCIP
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Peak Surge and Waves
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Statistical Surface
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Structural Alternatives
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Alternatives

• Existing Conditions LaCPR MsCIP
• LaCPR Alternatives MsCIP Existing
• MsCIP Alternatives LaCPR Existing
• A combination of preferred alternatives across
  the region can be modeled together.

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System Analysis

• Regional Perspective
• Engineered System Natural System

Lakes
Barrier Islands
Levees/Structures
Wetlands
Diversions
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Storm Surge and Wetlands

• Complicated Dynamics preclude application of
  simple rules of thumb (i.e. X miles of marsh
  reduces surge by Y feet)
• Storm track
• Storm intensity
• Surrounding topography/bathymetry
• Vegetation type
• Modeling is a tool for qualitative and/or
  semi-quantitative evaluation of the surge
  reduction potential of coastal restoration
  features.

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Storm Surge and Wetlands
Why the limitations?

• New application of the model and area of active
  research.
• Complicated physics
• Representation of physical system
• Friction factors
• Very limited data.
• Need to fund research for field and laboratory
  studies

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Wetland Restoration/Degradation
Biloxi Restored 0.33 m (NAVD88), Brackish
marsh Degraded -0.6 m (NAVD88), Open water
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Sensitivity Storms

• HUR2 (Hurricane Katrina-like)
• Central Pressure 900 mb
• Rmax 22 nm
• Forward Speed 11 knots

• HUR1 (Hurricane Hilda-like)
• Central Pressure 960 mb
• Rmax 22 nm
• Forward Speed 11 knots

Peak Surge
2.5 m
4 4.5 m
1.5 - 2 m
2 3.5 m
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Max Wave Height
HUR1
HUR2
H11m
H16m
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Biloxi Restoration
Surge Restored - Base
-10
-5 to 10
-20
-15
-30
-10
HUR1
HUR2
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Biloxi Restoration
Waves Restored - Base
HUR1
HUR2
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Biloxi Degradation
Surge Degraded - Base
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20
25
10
30
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HUR1
HUR2
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Biloxi Degradation
Waves Degraded - Base
HUR1
HUR2
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Barrier Island Sensitivity Analysis
Pre-Camille footprint 20 ft elevation
NAVD88 Assumes no morphologic change
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Barrier Island Sensitivity Analysis
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Advances

• Multi-process, multi-scale coupling that computes
  the interaction of tides, riverine flow, wind,
  atmospheric pressure, and wave radiation stress
  driven flow to determine water levels.
• Large domains that do not require ad-hoc boundary
  condition adjustments.
• Unprecedented system definition and grid
  resolution.
• No ad-hoc localized tuning

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RD Needs

• More data!
• Field data on surge and wave reduction by
  vegetated natural features
• Laboratory studies on wave and water level
  attenuation by vegetation
• Improved flow resistance formulations
• Assess importance of three-dimensional effects
• Integrate capability to simulate barrier
  island/levee degradation and breaching
• Integrate localized rainfall-runoff models
• Improve interfaces for sub-grid scale features
  such as levees

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End