Estimating the United States Population at Risk from Coastal Flood-Related Hazards

  • Mark Crowell
  • Jonathan Westcott
  • Susan Phelps
  • Tucker Mahoney
  • Kevin Coulton
  • Doug Bellomo
Part of the Coastal Research Library book series (COASTALRL, volume 1000)


Over the past couple of decades a number of papers have been published that provide estimates of United States population living in coastal areas. These estimates vary widely; ranging from less than 5%, to more than 50% of the U.S. population living in coastal areas. The reason for the wide range in estimates is that there are a variety of criteria that can be combined in a number of permutations to define “coastal areas.” For example, coastal areas may be defined based on probability of coastal flooding, inundation caused by future changes in sea levels, or simply by proximity to the coastline itself. In addition, spatial buffers, such as geopolitical units (e.g., counties and census block groups), or prescribed distances (e.g., 50- or 100-mile distance buffers), can also be used to provide a measure of uncertainty associated with economic exposure, or with measurement error. Other types and categories of defining criteria can be used to further characterize coastal areas. In this chapter we focused our attention on estimating U.S. population at risk from the 1% annual chance coastal flood. The 1% annual chance flood (both coastal and riverine) is used by FEMA in the administration of the National Flood Insurance Program (NFIP). The methods used in this analysis followed those of Crowell et al. (J Coast Res 26:201–211, 2010) who used a three-step process to determine coastal population: (1) create a national digital flood hazard database using FEMA (or FEMA-derived) datasets; (2) use a systematic method to separate coastal from riverine flood hazard areas; and (3) combine 2010 census block group data (assuming uniform population distribution) with the digital coastal flood hazard database using a geographic information system. The results of this analysis indicate that approximately 2.8% of the U.S. population lives in areas directly subject to 1% chance coastal flood. In addition, a total of 395 counties were found to be contiguous with the ocean or Great Lakes coast and/or have at least some coastal flood hazard areas (as based on the 1% annual chance coastal flood) located within their boundaries. About 39% of the U.S. population lives in these “coastal” counties.


Storm Surge Flood Hazard Federal Emergency Management Agency Coastal Population Coastal Flood 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would like to thank the following people for their review and comment on this chapter: Darryl Hatheway, Paul Rooney, Erin Walsh, and Theresa Goedeke.


  1. American Society of Civil Engineers (2006) Minimum design loads for buildings and other structures, ASCE/SEI 7–05. American Society of Civil Engineers, Reston, VAGoogle Scholar
  2. Bellomo D, Crowell M (2010) FEMA’s coastal population study: comments on data accuracy, current initiatives, and future risk. J Coast Res 26:199–200CrossRefGoogle Scholar
  3. Bellomo D, Pajak MJ, Sparks J (1999) Coastal flood hazards and the National Flood Insurance Program. In: Crowell M, Leatherman SP (eds) Coastal erosion mapping and management. Coastal Education and Research Foundation, Royal Palm BeachGoogle Scholar
  4. Bender MA, Knutson TR, Tuleya RE, Sirutis JJ, Vecchi GA, Barner ST, Held IM (2010) Modeled impact of anthropogenic warning on the frequency of intense Atlantic hurricanes. Science 327:454–458CrossRefGoogle Scholar
  5. Bhaduri B, Bright E, Coleman P (2007) LandScan USA: a high-resolution geospatial and temporal modeling approach for population distribution and dynamics. GeoJournal 69:103–117CrossRefGoogle Scholar
  6. Boak EH, Turner IL (2005) Shoreline definition and detection: a review. J Coast Res 21:688–703CrossRefGoogle Scholar
  7. Church JA, White NJ (2006) A 20th century acceleration in global sea level rise. Geophys Res Lett 33:1–4CrossRefGoogle Scholar
  8. Cohen JE, Small C (1998) Hypsographic demography: the global distribution of population with altitude. Proc Natl Acad Sci USA 95:14009–14014CrossRefGoogle Scholar
  9. Cohen JE, Small C, Mellinger A, Gallup J, Sachs J (1997) Estimates of coastal populations. Lett Sci 278:1211Google Scholar
  10. Crossett K, Culliton T, Wiley P, Goodspeed T (2004) Population trends along the coastal United States, 1980–2008. NOAA, Silver SpringGoogle Scholar
  11. Crowell M, Leatherman SP (eds) (1999) Coastal erosion mapping and management. J Coast Res Spec Issue 28:196Google Scholar
  12. Crowell M, Edelman S, Coulton K, McAfee S (2007) How many people live in coastal areas? (editorial). J Coast Res 23:iii–viCrossRefGoogle Scholar
  13. Crowell M, Coulton K, Johnson C, Westcott J, Bellomo D, Edelman S, Hirsch E (2010) An estimate of the U. S. population living in 100-year coastal flood hazard areas. J Coast Res 26:201–211CrossRefGoogle Scholar
  14. Culliton T (1998) Population: distribution, density, and growth. NOAA’s State of the coast report. NOAAGoogle Scholar
  15. Culliton TJ, Warren MA, Goodspeed TR, Remer TG, Blackwell CM, McDonough JJ (1990) 50 years of population change along the nation's coast, 1960–2010. National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce, Rockville, MarylandGoogle Scholar
  16. Federal Emergency Management Agency (1989) Erosion rate data study plan. Unpublished documentGoogle Scholar
  17. Federal Emergency Management Agency (1991) Projected impact of relative sea level rise on the National Flood Insurance Program.
  18. Federal Emergency Management Agency (2003) Guidelines and specifications for flood hazard mapping partners. Appendix A: Guidance for aerial mapping and surveyingGoogle Scholar
  19. Federal Emergency Management Agency (2007a) Atlantic ocean and Gulf of Mexico coastal guidelines update. Available at:
  20. Federal Emergency Management Agency (2007b) Revised procedure memorandum No. 38 – implementation of floodplain boundary standards (Section 7 of MHIP v1.0). 9 p, 17 Oct 2007. Available at:
  21. Federal Emergency Management Agency (2008) Coastal AE Zone and VE Zone demographics study and primary Frontal Dune study to support the NFIP, Technical Report. Unpublished, 98 pGoogle Scholar
  22. Heinz Center (2000) Evaluation of erosion hazard. Report prepared for Federal Emergency Management Agency (FEMA). Heinz Center, Washington, DC.
  23. Hinrichsen D (1990) Our common seas: coasts in crisis. Earthscan, London/NairobiGoogle Scholar
  24. Hinrichsen D (1998) Coastal waters of the world: trends threats, and strategies. Island Press, Washington, DCGoogle Scholar
  25. Hinrichsen D (1999) The coastal population explosion. In: Cicin-Sain B, Knecht RW, Foster N (eds) Trends and future challenges for U.S. National Ocean and coastal policy: proceedings of a workshop. NOAA, Washington, DCGoogle Scholar
  26. IPCC (2007) Climate change: the physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, Cambridge, Reston, VAGoogle Scholar
  27. Knutson TR, McBride JL, Chan J, Emanuel K, Holland G, Landsea C, Held I, Kossin JP, Srivastava AK, Sugi M (2010) Tropical cyclones and climate change. Nat Geosci 3:157–163CrossRefGoogle Scholar
  28. Lam NSN, Arenas H, Li Z, Liu KB (2009) An estimate of population impacted by climate change along the U.S. coast. J Coast Res 2(Spec Issue 56):1522–1526Google Scholar
  29. Lichter M, Vafeidis AT, Nicholls RJ, Kaiser G (2011) Exploring data-related uncertainties in analyses of land area and population in the “Low-Elevation Coastal Zone” (LECZ). J Coast Res 27:757–768CrossRefGoogle Scholar
  30. Miller L, Douglas BC (2004) Mass and volume contributions to 20th century global sea level rise. Nature 428:406–409CrossRefGoogle Scholar
  31. National Research Council of the National Academies (2009) Mapping the zone, improving flood map accuracy. National Academies Press, Washington, DCGoogle Scholar
  32. Nicholls RJ, Marinova N, Lowe JA, Brown S, Vellinga P, de Gusmão D, Hinkel J, Tol RSJ (2011) Sea-level rise and its possible impacts given a ‘beyond 4 °C world’ in the twenty-first century. Philos Trans R Soc A 369:161–181CrossRefGoogle Scholar
  33. NOAA Webpage (2012b) Retrieved 28 Feb 2012
  34. NOEP Webpage (2012) Accessed 28 Feb 2012
  35. Small C, Nicholls RJ (2003) A global analysis of human settlement in coastal zones. J Coast Res 19:584–599Google Scholar
  36. Small C, Gornitz V, Cohen JE (2000) Coastal hazards and the global distribution of human population. Environ Geosci 7:3–12CrossRefGoogle Scholar
  37. U.S. Army Corps of Engineers, Engineer Research and Development Center, Coastal Hydraulics Lab (2011) ERDC/CHL TR-11-1. FEMA Region III storm surge study, coastal storm surge analysis system digital elevation model, Report 1: intermediate submission No. 1.1, Vicksburg, MSGoogle Scholar
  38. U.S. Census Bureau (2012) Cartographic boundary files. Accessed 8 Mar 2012
  39. Vermeer M, Rahmstoef S (2009) Global sea level linked to global temperature. Proc Natl Acad Sci USA 106(21):527–532. doi:10.1073/pnas.0907765106 Google Scholar
  40. Wilson SG, Fischetti TR (2010) Coastline population trends in the United States: 1960 to 2008. US Dept Commerce, US Census Bureau, Washington. Available at:
  41. Zhang KQ, Douglas BC, Leatherman SP (2004) Global warming and coastal erosion. Clim Chang 64:41–58CrossRefGoogle Scholar
  42. Zhang K, Leatherman S (2011) Barrier island population along the U.S. Atlantic and Gulf Coasts. J Coast Res 27(2):356–363Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Mark Crowell
    • 1
  • Jonathan Westcott
    • 1
  • Susan Phelps
    • 2
  • Tucker Mahoney
    • 3
  • Kevin Coulton
    • 4
  • Doug Bellomo
    • 1
  1. 1.Federal Emergency Management AgencyArlingtonUSA
  2. 2.AECOMGreensboroUSA
  3. 3.Federal Emergency Management AgencyAtlantaUSA
  4. 4.AECOMPortlandUSA

Personalised recommendations