FLOOD INUNDATION MAP GRAPHIC

"Effective January 1, 2008,  the Southeast River Forecast Center will terminate the experimental real-time flood inundation mapping web service for three river locations along the Tar River - Rocky Mount, Tarboro, and Greenville.  This experimental service was only available when flooding was occurring or forecast.
The Uniform Resource Locator for this web page is

http://www.srh.noaa.gov/alr/inundation/tar.htm

On October 22, 2007, the National Weather Service, in collaboration with the state of North Carolina, implemented static flood inundation map libraries for seventeen locations in North Carolina.   Information about this new suite of flood inundation maps is available at the following web address:

http://www.weather.gov/os/notification/scn07-50_floodmap-nc.txt

This new information service will provide our customers with a planning tool when flooding is occurring or is forecast to occur.  It also provides additional information not available with the experimental real-time flood inundation mapping service, such as an aerial photographic views of the flood inundation areas for various water level intervals, including the 100- and 500-year floods.

If you have any questions about this change, please contact the following individuals:

John Feldt
Hydrologist-in-Charge, Southeast River Forecast Center  Phone: 770-486-0028  email: john.feldt@noaa.gov
 

Part I - Mission Connection

• Product Description - The NWS Southeast River Forecast Center produces river stage forecasts for several hundred locations in the Southeast U.S. These forecasts reference numeric gage heights at a single site along the river, generally in or near a city. The experimental Flood Inundation Map Graphics show the lateral extent of projected flooding on local map backgrounds. Currently, they are only being produced during flooding events for a section of the Tar River in North Carolina.

Four graphics are available: One for the entire reach of the Tar River for which the flood
inundation mapping is performed, and one each that covers the cities of Rocky Mount,
Tarboro, and Greenville.

• Purpose/Intended Use - Flood Inundation Maps will show the extent of flooding expected spatially over a given area. This will indicate when roadways, streets, buildings, airports, etc. are likely to be impacted by floodwaters. The accuracy of the mapping depends on the degree of accuracy of DEM data available for use in the GIS application, plus other factors.



• Audience - The initial target audience is the state and local agencies that must make emergency operational decisions during flooding events. However, since the graphics are easy to view, anyone with an interest during these events can make use of the maps, including the Federal Emergency Management Agency (FEMA), the U.S. Geological Survey (USGS), Corps of Engineers (COE), state and local emergency managers, the media, and the general public.



• Presentation Format - The Flood Inundation Maps are web-based graphics. A text version of the actual river forecast numbers is also available. The web-page has a description of the product and there are four views/maps available. Each view/map will show the maximum extent of the flood inundation for the 7 day forecast period, plus instantaneous inundation at 6 hour intervals for the next 72 hours.



• Feedback Method - Comments regarding the SERFC Flood Inundation Maps should be sent to the feedback e:mail address on the webpage containing the product. A survey link will also be available on the webpage. Comments may also be provided to:

Southeast River Forecast Center
4 Falcon Drive
Peachtree City, GA 30269
Attn: John Feldt

John.Feldt@noaa.gov

Experimental Feedback Period: January 1 through November 30, 2004.

Part II - Technical Description

• Format and Science Basis - Inundation areas depicted in the maps are derived using two models plus a Geographic Information System (GIS). The NWS hydrologic model is used to predict the amount of flow in entering the Tar River at various points. Using these predicted flows, a dynamic routing model, FLDWAV, is used to predict a profile of water surface elevations. This FLDWAV implementation predicts the water surface profile only along the Tar River main stem, and is not intended to predict water surface elevations on tributaries. A map, that provides a visual depiction of a flood forecast, is created using a series of GIS algorithms and is then posted to our web page. The text product for the numerical forecast is available from a link on the web page. A sample of this product can be found at: http://www.srh.noaa.gov/alr/inundation/peak.htm



• Product Availability - The SERFC Tar River Flood Inundation Maps will be produced and sent to the web daily.



• Additional Information - Contact John Feldt (John.Feldt@noaa.gov) or Wylie Quillian (Wylie.Quillian@noaa.gov) at SERFC (phone 770-486-0028).