3-D Flood Risk Visualization Beth Norton December 21, 2011

2 Background  Floods are one of the most common hazards in the US  FEMA provides flood risk data to community officials through flood mapping products  Participating communities in the NFIP regulate and enforce the flood maps

3 Problem  Risky decisions are made Communities allowing development in the floodplain Developers buying land and building homes in the floodplain  The impacts of these decisions aren’t borne by those making them Homeowners purchase the risk Federal government insures the risk First responders risk their lives to rescue people at risk  Flood maps are 2-D and don’t portray immediate risk The forces of flood damage can’t be shown on a 2-D map.  Homeowners and potential homebuyers need tailored information

4 2-D Flood Map

5 Flooding Damage Forces  Hydrodynamic Forces Moving water The faster the water, the greater the pressure and erosion.  Hydrostatic Forces Standing water The deeper the water, the more it weighs and greater the pressure. 3 feet of standing water can collapse a standard frame house  Debris Ice floes Large objects Sediment  Soaking Damages building materials and household goods *Source: FEMA: Managing Floodplain Development through the NFIP, 2/15/2010

6 Proposal (Solution) 500 year 100 year 50 year

7 Proposal (Solution) 500 year 100 year 50 year

8 Process  Software Sketch Up  3-D Buildings 3D Analyst  3-D flood hazard data ArcScene  Visualization

9 Data  Provided by the NCFMP  Base Data 2010 Orthoimagery Street Centerlines Streams Tax Assessor Data LiDAR  Built-Environment Data Digitized Building Footprints Building Photos  Raster Datasets Water Surface Elevation (WSEL) and Depth Rasters (Multi-Return Periods)  10, 25, 50, 100, and 500 years

10 Data (cont)  Risk Data Building Footprints attributed with  First Floor Elevations  Lowest and Highest Adjacent Grade  Number of stories  Estimated building and content loss  Flood Depths  Flood Elevations  Annualized Damages  Regulatory Data FIRM FIS Database

11 Project Area  Tarboro, Edgecombe County, NC* Population – 13,121 Land Area – 9.8 square miles Flood History  July 1919 flood  Exceeded the 100-year flood  Hurricane Floyd, 1999  Exceeded the 500-year flood  $5 Billion in damages to NC  Hurricane Irene, 2011 * Source: 11/3/2004 FEMA Flood Insurance Study, Edgecombe County, NC

12 Project Area - Overview *Source:

13 Project Area - Residential *Source:

14 Project Area – Residential and Commercial *Source:

15 Project Area – Lower Residential *Source:

16 Project Area - Undeveloped *Source:

17 Questions ????