Location: Jacksonville, FL December 11, 2012

Transcription

1 Technical Update Meeting Northeast Florida Surge Study Location: Jacksonville, FL December 11, 2012

2 Agenda 2:00 2:15 Welcome/Introductions Tucker Mahoney, FEMA Region IV Michael DelCharco, BakerAECOM 2:15 2:30 Project Overview Michael DelCharco, BakerAECOM 2:30 3:15 Technical Presentation Chris Bender, BakerAECOM 3:15 4:00 Questions and Answers All Jacksonville, FL Nassau County, FL 2

3 Introductions Risk MAP Project Team FEMA Region IV BakerAECOM, LLC (Production and Technical Services (PTS) contractor) Michael Baker Corp. AECOM, Taylor Engineering, Inc. Marea Technology, LLC University of Central Florida St Johns County, FL University of Notre Dame Oceanweather, Inc. Worldwinds, Inc. Open Introductions ( Hi, I am Scott from. ) 3

4 Goals for Today s Meeting Continue engagement with technical community Provide overview of FEMA Risk MAP Program and Region IV Coastal Flood Risk Study Project for Northeast Florida (NEFL) Provide overview of project schedule Provide overview of surge study for NEFL and status of work performed Discuss study methodology and initial results Mesh Development Storm Climatology Validation Storms Answer your questions 4

5 FEMA Region IV Coastal Flood Risk Studies in Florida 5

6 Why Surge Analysis for NEFL Was Updated Your flood risk changes over time. There has been significant development in the counties. Significant flood risk from coastal storms (hurricanes, tropical storms, nor'easters) Increase in population and development since current effective FIRMs published A complete, current picture of your coastal flood hazards and risks will help you better: Plan for the risk Take action to protect your communities Communicate the risk to your citizens 6

7 Why Surge Analysis for NEFL Was Updated (Cont d) Your risk is better defined through Updated guidelines Atlantic Ocean and Gulf of Mexico Guidelines Update (2007) Sheltered Water Report (2008) PM 50 Limit of Moderate Wave Action (LiMWA) (2008) Updated elevation data (topographic data and aerial imagery) New climatological data based on recent storms Newer coastal hazard methodologies (developed since Hurricane Katrina) Improvement in Geographic Information System (GIS) technologies to improve coastal mapping accuracy 7

8 Risk Mapping, Assessment, and Planning (Risk MAP) Overview FEMA works with you and other communities to develop flood risk products and flood hazard maps that are: Based on the best available data from community and latest technologies Conducted by affected communities and counties (coastal) Strengthened by partnerships You can use Risk MAP tools and data to: Create or improve your Hazard Mitigation Plans Make informed decisions about development, ordinances, and flood hazard mitigation projects Communicate with citizens about flood risk 8

9 Program Product Comparisons Traditional Regulatory Products Non-Regulatory Products DFIRM Database Traditional NFIP products are regulatory and subject to statutory due-process requirements. New Risk MAP products are nonregulatory and are not subject to statutory due-process requirements. 9

10 Project Work Plan Perform coastal storm surge and wave height analyses for GA and NEFL counties Develop coastal floodplain boundary delineations and produce work maps Develop Risk MAP regulatory/non-regulatory products Support outreach to facilitate state and local ownership Produce/distribute Preliminary FIRMs and Flood Insurance Study (FIS) reports Support FEMA for CCO Meeting/Open House and post- Preliminary processing 10

11 Coastal Flood Risk Study Timeline 11

12 Projected Schedule Production Runs: May 2013 Statistical Analysis: June 2013 Overland Wave Analysis: December 2013 Flood Hazards Work Maps: September 2014 Produce FIRMs: March 2015 Hold CCO Meetings/Open Houses: June 2015 Post-Preliminary Activities: Begin June 2015 End June

13 Extent of Coastal Surge Study NEFL Duval Flagler Nassau St. Johns Volusia Coastal Counties Georgia Bryan Camden Chatham Glynn Liberty McIntosh Clay Putnam Interior Counties Brantley Charlton Effingham Long Wayne 13

14 Basic Elements of a Coastal Flood Risk Study Base Flood Elevation (BFE) on a FIRM includes four components: Storm surge stillwater elevation (SWEL) Wave setup Wave height above total SWEL Wave runup above storm surge elevation (where present) All applied to an eroded beach profile (when applicable) The above components are computed through Terrain processing and profile erosion Storm surge study for SWEL determination Coastal hazard analysis 14

15 Approach - Storm Surge SWEL Storm Forcing Hurricane Tracks Storm Surge Modeling Winds Waves Return Period Analysis JPM-OS 2%, 1%, 0.2% Annual Chance Tide Gage Analysis 50%, 20%, 10% A.C. SWEL Water Levels High-Resolution Bathymetry / Topography Mesh Surge (m) jpm stochastic Return Period (years) JPM-OS: Joint Probability Method - Optimum Sampling 15

16 Storm Surge Modeling System Wind and Pressure Fields Water Levels Waves/ Radiation Stress Coupling ADCIRC Coastal Circulation and Storm Surge Model SWAN Offshore and Coastal Waves Radiation Stress 16

17 Available Data and Documentation Reviewed To Date Topography LIght Detection and Ranging (LIDAR) systemgenerated data Bathymetric Data NOAA National Ocean Service (NOS) database, U.S. Army Corps of Engineers (USACE) Historic FIS reports (including Preliminary FIS reports in production) Aerial images Boundary, hydrography, and transportation layers Water level and wave gage records Meteorological records Post-storm data reports St Augustine, FL 17

18 Initial Results Model Mesh Development Developed seamless topographic and bathymetric data surface (Digital Elevation Model [DEM]) Developed SWAN+ADCIRC Mesh Tasks completed in parallel Storm Climatology Validation Storm Selection Validation Comparisons 18

19 Seamless Topographic and Bathymetric Data Surface (DEM) Development Shoreline LIDAR National Elevation Dataset Geo Database Seamless Topographic/ Bathymetric Data Surface Convert to NAVD88 GEOphysical Data Management System Electronic Navigational Charts USACE/SJRWMD Hydro Survey NAVD88: North American Vertical Datum of

20 LIDAR Coverage 20

21 LIDAR Coverage (Cont d) 21

22 LIDAR Coverage (Cont d) 22

23 LIDAR Coverage (Cont d) 23

24 Bathymetric Data Coverage NOS Database USACE Hydro Survey St. Johns River Water Management District (SJRWMD) Data NOAA (Nautical Charts) Existing FISs 24

25 Bathymetric Data Coverage (Cont d) USACE SJRWMD 25

26 Bathymetric Data Coverage (Cont d) NOS Data, Different Survey Dates and Data Extents 26

27 Bathymetric Data Coverage (Cont d) Same Area, Different Data Sources, Survey Dates, and Data Extents 27

28 Seamless Topographic and Bathymetric Data Surface 28

29 Seamless Topographic and Bathymetric Data Surface (Cont d) 29

30 SWAN+ ADCIRC Model Mesh Development SWAN+ADCIRC Model Finite element model Uses unstructured, triangulated mesh Node spacing set to accurately represent topography/bathymetry Created feature arcs to represent elevated or depressed features (i.e. roads or channels) 30