Georgia and Northeast Florida Coastal Storm Surge and Mapping

Georgia and Northeast
Florida Coastal Storm
Surge and Mapping
Study
Presented by Christopher Bender, Ph.D., P.E., D.CE
February 14, 2013
Presentation Overview
• FEMA risk studies outline
• Overview Georgia and northeast
Florida surge study
• Work completed and project status
• Study methodology and initial results
 Mesh development
 Validation storm selection
 Validation results
• Questions?
FEMA Region IV Coastal Flood Risk
Studies in Florida
GANEFL Coastal Surge Study Extent
NEFL
Georgia
Coastal Counties
Duval
Bryan
Flagler
Camden
Nassau
Chatham
St. Johns
Glynn
Volusia
Liberty
McIntosh
Interior Counties
Clay
Brantley
Putnam
Charlton
Effingham
Long
Wayne
Approach – Storm Surge SWEL
Initial Results
• Model Mesh Development
 Developed seamless topographic and bathymetric data
surface (Digital Elevation Model [DEM])
 Developed SWAN+ADCIRC mesh
 Completed tasks in parallel
• Validation Storm Selection
• Validation Comparisons
Seamless Topographic and Bathymetric
Data Surface (DEM) Development
Seamless Topographic and Bathymetric
Data Surface
SWAN+ ADCIRC Model Mesh Development
• SWAN+ADCIRC model
• Finite element model
• Uses unstructured,
triangulated mesh
• Node spacing set to
accurately represent
topography/bathymetry
• Applies “feature arcs” to
represent elevated or
depressed features (e.g.,
roads or channels)
SWAN+ ADCIRC Model Mesh Development
SWAN+ADCIRC Mesh – Duval County
Jacksonville
Beaches, FL
SWAN+ADCIRC Mesh – Duval County
Initial Results
• Model Mesh Development
 Developed seamless topographic and bathymetric data
surface (DEM)
 Developed SWAN+ADCIRC mesh
 Completed tasks in parallel
• Validation Storm Selection
• Validation Comparisons
Validation Storm Selection: Significant
Surge Events 1950 – 1959
Landfalling, bypassing,
exiting storms that
passed near study area
Validation Storm Selection: Significant
Surge Events 2000 – 2010
Landfalling, bypassing,
exiting storms that
passed near study area
Validation Storm Selection: Significant
Surge Events (Cont’d)
Criteria Sorting of Storms
1. Local
Landfall
2. Significant WL
Difference
3. WL Data Availability
(more than 3 stations)
4. Wave Data Availability
(2 or more stations)
Cleo
Dora
David
Chris
Edouard
Tammy
Fay
Dora (5.91 ft)
David (5.55 ft)
Jeanne (4.22 ft)
Tammy (4.07 ft)
Fay (3.99 ft)
Frances (3.85 ft)
Gabrielle (3.82 ft)
Floyd (3.8 ft)
Ophelia (3.04 ft)
Abby (2.93 ft)
Irene (2.92 ft)
Bertha (2.62 ft)
Bob (2.44 ft)
Erin (2.43 ft)
Cleo (2.35 ft)
Dennis 99 (2.24 ft)
Frances (15)
Charley (14)
Jeanne (14)
Ophelia (9)
Tammy (9)
Dennis 99 (8)
Edouard (8)
Floyd (7)
Irene (7)
Fay (6)
David (5)
Frances (5)
Ophelia (5)
Tammy (5)
Fay (5)
Jeanne (4)
Edouard (3)
Charley (3)
Chris (2)
Dennis99 (2)
Floyd (2)
Irene (2)
Validation Storm Selection: Significant
Surge Events (Cont’d)
Criteria Sorting of Storms
1. Local
Landfall
2. Significant WL
Difference
3. WL Data Availability
(more than 3 stations)
4. Wave Data Availability
(2 or more stations)
Cleo
Dora
David
Chris
Edouard
Tammy
Fay
Dora (5.91 ft)
David (5.55 ft)
Jeanne (4.22 ft)
Tammy (4.07 ft)
Fay (3.99 ft)
Frances (3.85 ft)
Gabrielle (3.82 ft)
Floyd (3.8 ft)
Ophelia (3.04 ft)
Abby (2.93 ft)
Irene (2.92 ft)
Bertha (2.62 ft)
Bob (2.44 ft)
Erin (2.43 ft)
Cleo (2.35 ft)
Dennis 99 (2.24 ft)
Frances (15)
Charley (14)
Jeanne (14)
Ophelia (9)
Tammy (9)
Dennis 99 (8)
Edouard (8)
Floyd (7)
Irene (7)
Fay (6)
David (5)
Frances (5)
Ophelia (5)
Tammy (5)
Fay (5)
Jeanne (4)
Edouard (3)
Charley (3)
Chris (2)
Dennis99 (2)
Floyd (2)
Irene (2)
Validation Storm Selection: Significant
Surge Events (Cont’d)
Selected five validation storms
• Hurricane Dora (1964)
• Hurricane David (1979)
• Hurricane Frances (2004)
• Tropical Storm Tammy (2005)
• Tropical Storm Fay (2008)
Initial Results
•
•
•
Model Mesh Development
 Developed seamless topographic and bathymetric data
surface (DEM)
 Developed SWAN+ADCIRC Mesh
 Completed tasks in parallel
Validation Storm Selection
Validation Comparisons
Validation: Tides
Tide validation based on
comparisons to NOAA stations
with tidal constituent data
Validation: Tides; Amplitude
Validation: Tides; Phase
Validation WSE: Historical Storms;
Hurricane Dora
Validation WSE: Historical Storms;
Hurricane Dora (cont’d)
Duval and Nassau Counties, FL
Validation WSE: Historical Storms;
Hurricane Dora (cont’d)
Validation WSE: Historical Storms; All
Validation Waves: Hurricane Frances
Validation Waves: Hurricane Frances
Validation Waves: All Storms
Validation Waves: All Storms
Summary
• DEM and model mesh developed with best available data
 Include features that alter storm surge
• Historical storms selected to validate model WSE and
wave values
• SWAN+ADCIRC model results compare well to data
 Tide, storm WSE and storm wave data
• Next phase will complete production runs, develop
% annual chance WSE’s, and move onto work maps
THANK YOU