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Mapping the Zone Improving Flood Map Accuracy (2009) / Chapter Skim
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Appendix C: Glossary
Pages 113-120

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From page 113...
... Limitations of map scale and development of topographic data more accurately 1 Percent Annual Chance Flood -- A flood that has a reflecting the existing ground elevations at the time the 1 percent chance of being equaled or exceeded in any maps were prepared are the two most common bases given year; also known as a 100-year flood (FEMA, for amendment requests (FEMA, 2003)
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From page 114...
... Detailed Study, Coastal -- A coastal flood hazard study that uses transects and offshore bathymetry to conduct Coastal Flooding -- Flooding that occurs along the detailed erosion, wave height, and wave runup analyses Great Lakes, the Atlantic and Pacific Oceans, and the and to prepare floodplain mapping. The analysis results Gulf of Mexico (FEMA, 2003)
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From page 115...
... the Flood Insurance Rate Map that has been prepared unusual and rapid accumulation or runoff of surface as a digital product, which may involve converting an waters from any source (FEMA, 2003) existing manually produced FIRM to digital format or creating a product from new digital data sources using a Flood Hazard Mapping Partner -- Community offigeographic information system (GIS)
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From page 116...
... When a flood study is completed for the NFIP, Freeboard -- A factor of safety usually expressed in feet the information and maps are assembled into an FIS. above a flood level for purposes of floodplain manageThe FIS report contains detailed flood elevation data ment.
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From page 117...
... The analysis results in the delineation of floodplain Hydraulic Model -- A computer program that uses boundaries for the 1 percent annual chance (100-year) flood discharge values and floodplain characteristic flood and often base flood elevations (FEMA, 2006a)
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From page 118...
... -- The area Redelineation -- A data update method that involves delineated on an NFIP map as being subject to inunno new analyses, but uses effective information and dation by the base flood. SFHAs are determined using new topographic data that are more up-to-date and/or statistical analyses of records of riverflow, storm tides, detailed than those used to produce the effective FIRM and rainfall; information obtained through consultation to redelineate floodplain boundaries (FEMA, 2003)
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From page 119...
... instrument for the rapid determination of distance, usually together with the measurement of direction Wave Envelope -- A combination of representaand difference of elevation () determined by the wave results computed using the Wave Height Analysis for Flood Insurance Studies Transect -- Cross section taken perpendicular to the (WHAFIS)
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Key Terms

  • flood hazard
  • annual chance
  • percent annual
  • base flood
  • insurance rate

  • rate map
  • flood elevation
  • chance flood
  • percent chance
  • topographic data

  • hydraulic analyses
  • flood risk
  • flood elevations
  • insurance risk
  • elevation data

  • nfip map
  • hazard study
  • fis report
  • detailed flood
  • determine flood

  • coastal flood
  • flood maps
  • national flood
  • flood hazards
  • special flood

  • flood depths
  • insurance program
  • insurance study
  • agency officials
  • flooding source


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