Risk and Vulnerability to Natural Hazards

A fundamental element of the USGS mission is to provide reliable scientific information to minimize loss of life and property from natural disasters. Understanding risk requires an understanding of the regional hazards and also of societal vulnerability to these threats, defined as the exposure, sensitivity and resilience of coupled human-environmental systems (figure 1).

Figure 1. Risk is a function of natural hazards and vulnerable human-environmental systems. (schematic from Wood, 2008)

Decision makers need assistance in the form of model development and case study assessments to better understand community vulnerability to natural hazards. Research outlined here furthers our Nation’s ability to assess and manage the potential risks posed by natural hazards, to mitigate potential impacts of natural hazards and to respond and recover efficiently when catastrophic natural disasters do occur.

Scientific research questions addressed in this project focus on the use of geospatial data, GIS techniques, collaborative process, dasymetric mapping, factor analysis, and systems analysis in characterizing community vulnerability. Research includes community vulnerability to tsunamis (Oregon, Washington, and Hawaii), volcanoes (Mount Rainier, Washington), hurricane storm surge (Florida) and climate-change-enhanced coastal hazards (Oregon and Washington coast). Specific project elements include:

• Community Vulnerability to Tsunamis: The 2004 Indian Ocean disaster demonstrated that tsunamis are significant threats to coastal communities. Although tsunami-hazard areas have been identified in Washington, Oregon, and Hawaii, far less is known on potential impacts of these tsunamis to coastal communities (GAO 2006). In collaboration with State emergency managers in Oregon, Washington, and Hawaii, USGS researchers assessed spatial variations in community exposure (e.g., residents, developed land, economic assets) to relevant tsunami hazards in each State (figure 2). State-level USGS reports generated by this project (see publications below) help emergency managers to identify needed preparedness, mitigation, and outreach activities within specific communities and economic sectors along the Oregon, Washington, and Hawaiian coasts. Geographic research under this task includes assessing the use of midresolution landcover data, principal component analysis, and collaborative process (figure 3) in vulnerability efforts.

  Figure 2. Recent research suggests that a Cascadia subduction zone earthquake could create tsunami waves that impact over 1,000-km of coastline in the U.S. and Canada. To understand local community vulnerability posed by these hazards, USGS researchers are assessing variations in land-cover patterns, demographic characteristics, and business and employment patterns. Figures include landcover patterns in predicted tsunami zones of three Oregon towns (2a), distribution of residents in tsunami-prone areas (2b) and final composite indices of exposure and sensitivity (2c) to Oregon tsunami hazards (all from Wood, 2008).

  Figure 3. USGS researcher Rachel Sleeter (left) speaking with representatives from U.S. Postal Service and Oregon Department of Transportation at the Post-Disaster Tsunami Recovery Forum in Cannon Beach, Oregon, March 2, 2006

  
  
  
  
  
• Coastal storms and climate change: The devastation along the Gulf of Mexico coast resulting from Hurricane Katrina demonstrated the vulnerability of coastal communities to coastal-storm hazards. In addition to current socioeconomic pressures, sea-level rise (SLR) due to climate changes increases future societal vulnerability significantly by exposing new parts of a community to potential inundation and increased coastal erosion from hurricanes and winter storms. Research focuses on developing methodologies that integrate scientific understanding of coastal storm potential, coastal-change hazards and sea-level rise with human dynamics of population growth and development. Methods include GIS-based analysis and stakeholder-based deliberations. Case studies include future hurricane storm surge potential in Sarasota County, Florida in collaboration with Pennsylvania State University (figure 4) and future coastal erosion hazards along the Oregon and Washington coasts in collaboration with Oregon State University.

  Figure 4. Map of potential storm-surge inundation from a Category 5 hurricane, inundation from a Category 5 hurricane plus a projected 90 cm increase in sea level, and the 28 incorporated cities of Sarasota County (from Frazier et al., 2007).

  
  
  
  
  
• Volcanoes and societal vulnerability: As the 1980 Mount St. Helens eruption showed, volcanoes pose significant threats to Pacific Northwest communities. Although past eruptions of Mount Rainier have been less frequent and explosive than those of Mount St. Helens, increasing urbanization of the South Puget Sound lowlands makes Mount Rainier a greater regional threat to life and property (Driedger and Scott 2003, Sisson 1995) and represents the most severe flow risks of any volcano in the United States (Scott and Vallance 1995). Although most Mount Rainier hazards extend only a few miles beyond its National Park boundaries, lahars pose threats to Puget Sound communities, where over 150,000 people currently reside on lahar deposits (Driedger and Scott 2003). Research focuses on assessing spatial variations in community exposure to lahar hazards related to Mount Rainier (figure 5) and on including socioeconomic metrics into the USGS National Volcano Early Warning System. GIS-based analysis describes and summarizes regional community exposure and sensitivity to volcano lahar hazards (expressed in terms of land use, populations, and economic assets) and identifies community outliers in community exposure and sensitivity to lahar hazards.

  Figure 5. Map of counties, incorporated cities, and census-designated places with land in a lahar-hazard zone associated with Mount Rainier, Washington (from Wood and Soulard, in review). Lahar-hazard zone is from Hoblitt et al., 1998.

  
  
  
  
  
• Technology Transfer: The USGS has created and delivered multi-hazard vulnerability assessment workshops in collaboration with the Oregon Partners for Disaster Resistance and Resilience, a statewide initiative that includes the Oregon Natural Hazards Workgroup, the USGS and Oregon Emergency Management, as well as local and state land use and emergency planners (Figure 6). This one-day training helps land use and emergency managers to understand the consequences and implications of their land use decisions and provides information that helps them meet requirements of the Disaster Mitigation Act of 2000. It also furthers USGS researchers in their efforts to develop indicators of societal vulnerability that include local values and priorities. Since 2003, trainings have been held for emergency and land use planners of counties in the Willamette Valley, along the Columbia Gorge, along the northwest coast, and in eastern Oregon.
  

  
  
  
  
  Figure 6. Representatives from Hood River County, Oregon, at the 2006 Vulnerability Assessment Workshop, in The Dalles, Oregon, January 25, 2006

Publications and Websites:

USGS Reports:

1. Wood, N., and Soulard, C., in review, Community exposure to lahar hazards from Mount Rainier, Washington, U.S. Geological Survey Scientific Investigative Report.
   
   
2. Wood, N., 2008, Amount and percentage of current societal assets in areas on Kaua'i, Hawai'i, within the 1992 Hurricane 'Iniki storm-surge inundation zone: U.S. Geological Survey Open-File Report 2008-1280, 12 p. [ http://pubs.usgs.gov/of/2008/1280/].
   
   
3. Wood, N., 2008, Variations in city exposure and sensitivity to tsunami hazards in Oregon: U.S. Geological Survey Scientific Investigative Report 2007-5283, 43 p. [http://pubs.usgs.gov/sir/2007/5283/]
   
   
4. Wood, N. and Soulard, C., 2008, Variations in community exposure and sensitivity to tsunami Hazards on the open-ocean and Strait of Juan de Fuca coasts of Washington: U.S. Geological Survey Scientific Investigative Report 2008-5004, 34 p [http://pubs.usgs.gov/sir/2008/5004/]
   
   
5. Wood, N., Church, A., Frazier, T., and Yarnal, B., 2007, Variations in community exposure and sensitivity to tsunami hazards in the State of Hawai'i: U.S. Geological Survey Scientific Investigative Report 2007-5208, 42 p. [http://pubs.usgs.gov/sir/2007/5208/]
   
   
6. McMahon, G., Benjamin, S., Clarke, K., Findley, J., Fisher, R., Graf, W., Gundersen, L., Jones, J., Loveland, T., Roth, K., Usery, E., and N. Wood, 2005, Geography for a changing world: a science strategy for the geographic research of the U.S. Geological Survey, 2005-2015, Circular 1281, U.S. Department of the Interior, U.S. Geological Survey, Reston, Virginia, 54 p.
   
   

Journal Articles:

1. Wood, N., and Soulard, C., in review, Variations in population exposure to lahar hazards from Mount Rainier, Washington, for external publishing
   
   
2. Wood, N., Burton, C., and Cutter, S., in press, Community variations in social vulnerability to Cascadia-related tsunamis in the U.S. Pacific Northwest, Natural Hazards (DOI 10.1007/s11069-009-9376-1)
   
   
3. Wood, N., 2009, Tsunami exposure estimation with land-cover data: Oregon and the Cascadia subduction zone, Applied Geography 29, 158-170.
   
   
4. Bernknopf, R., Rabinovici, S., Wood, N., and Dinitz, L., 2006, The influence of hazard models on GIS-based regional risk assessments and mitigation policies, International Journal of Risk Assessment and Management, 6 (4/5/6), 369-387.
   
   
5. Wood, N., and Good, J., 2005, Perceptions of earthquake and tsunami issues in U.S. Pacific Northwest port and harbor communities, International Journal of Mass Emergencies and Disasters, 23 (3), 103–138.
   
   
6. Wood, N., and Good, J., 2004, Vulnerability of a port and harbor community to earthquake and tsunami hazards: the use of GIS in community hazard planning, Coastal Management, 32 (3), 243-269.
   
   
7. Wood, N., Good, J., and Goodwin, B., 2002, Community-based vulnerability assessment of a port and harbor to earthquake and tsunami hazards: Yaquina Bay, Oregon, Natural Hazards Review, 3 (4), 148-157.
   
   

Conference Proceedings:

1. Frazier, T., Wood, N., and Yarnal, B., 2009, A framework for using GIS and stakeholder input to assess vulnerability to coastal-inundation hazards: a case study from Sarasota County, Florida, Proceedings of the 2008 North Atlantic Treaty Organization (NATO) Advanced Training Course "Spatial planning as a strategy for mitigation and adaptation to natural hazards," Santiago de Compostela, Spain
   
   
2. Wood, N., 2008, Use of midresolution land-cover data for rapid comparison of community vulnerability to tsunamis, Proceedings of the 2006 North American Land Cover Summit, Washington, D.C., Campbell, J.C., Jones, K.B., Smith, J.H., Koeppe, M.T., (eds.), Washington, DC: Association of American Geographers, p. 169 – 180.
   
   
3. Wood, N., 2007, Appendix C.1.1 Hazard assessment – Introduction, in Bernard, E., Dengler, L., and Yim, S., (eds.), National Tsunami Research Plan—report of a workshop sponsored by NSF/NOAA, N OAA Technical Memorandum OAR PMEL-133, p. 51.
   
   
4. Frazier, T., Wood, N., and Yarnal, B., 2007, Current & future vulnerability of Sarasota County, Florida, to hurricane storm surge & sea level rise, Proceedings of the Solutions to Coastal Disasters 2008 Conference, Oahu, Hawai`i, p. 210-221.
   
   
5. Wood, N., 2006, Variations in community vulnerability to tsunami hazards on the U.S. Pacific Northwest coast, Proceedings: International Disaster Reduction Conference, Davos, Switzerland, volume 3, pp. 649-652.
   
   
6. Sleeter, R., and Wood, N., 2006, Estimating daytime and nighttime population density for coastal communities in Oregon: Proceedings of the Urban and Regional Information Systems Association, Annual Conference, Vancouver, BC, September 26-29, 2006, 8 p.
   
   
7. Wood, N., Good, J., and Goodwin, B., 2002, Reducing vulnerability of ports and harbors to earthquakes and tsunamis, Proceedings: Solutions to Coastal Disasters ’02 Conference, American Society of Civil Engineers, Reston, Virginia, p. 949-963.
   
   
8. Wood, N., 2001, Vulnerability assessment of a port and harbor community to earthquake-tsunami hazards, [abs.]: Vulnerability Assessment Techniques II Workshop, National Oceanic and Atmospheric Administration Coastal Services Center, Charleston, South Carolina.
   
   
9. Wood, N., and Stein, D. 2001, A GIS-based vulnerability assessment of Pacific Northwest ports and harbors to tsunami hazards, Proceedings, International Tsunami Symposium '01, Seattle, Washington, 367 - 374
   
   
10. Wood, N. and Good, J., 2000, Natural hazards decision-making: the role of stakeholder needs and scientific input, Proceedings: Coasts at the Millennium, 17th Conference of The Coastal Society, Portland, Oregon: p. 371-379.
    
    

Workshops:

1. Wood, N., LeDuc, A., and Mitchell, K., 2008, Vulnerability Assessment Training, workshop held in Astoria, Oregon, as part of the Oregon Partners for Disaster Resilience
   
   
2. Wood, N., LeDuc, A., and Mitchell, K., 2007, Vulnerability Assessment Training, workshop held in Ontario, Oregon, as part of the Oregon Partners for Disaster Resilience
   
   
3. Wood, N., LeDuc, A., and Mitchell, K., 2006, Vulnerability Assessment Training, workshop held in The Dalles, Oregon, as part of the Oregon Partners for Disaster Resilience
   
   
4. Wood, N., LeDuc, A., and Mitchell, K., 2005, Vulnerability Assessment Training, workshop held in Portland, Oregon, as part of the Oregon Partners for Disaster Resilience