U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2007-5283

Variations in City Exposure and Sensitivity

to Tsunami Hazards in Oregon
This page is left intentionally blank.
Variations in City Exposure and Sensitivity 

to Tsunami Hazards in Oregon

By Nathan Wood

Scientific Investigations Report 2007-5283

U.S. Department of the Interior

U.S. Geological Survey
ii

U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

This report and any updates to it are available at:

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Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Wood, Nathan, 2007, Variations in city exposure and sensitivity to tsunami hazards in Oregon: U.S. Geological Survey 

Scientific Investigations Report 2007-5283, 37 p.

Cataloging-in-publication data are on file with the Library of Congress (http://www.loc.gov/).

Produced in the Western Region, Menlo Park, California

Manuscript approved for publication, December 12, 2007

Text edited by James W. Hendley II

Layout by David R. Jones

FRONT COVER—The cities of Manzanita (left) and Seaside (right) on the Oregon coast, shown with the internationally 

adopted tsunami-evacuation sign (Intergovernmental Oceanographic Commission, 2003). (USGS photographs by 

Nathan Wood.)
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Purpose and Scope ..............................................................................................................................3

Study Area ......................................................................................................................................................4

Methods and Data .........................................................................................................................................5

Land Data ...............................................................................................................................................5

Population Data.....................................................................................................................................5

Economic Data ......................................................................................................................................7

Critical-Facilities Data .........................................................................................................................7

Composite Indices of Exposure and Sensitivity...............................................................................8

Statistical Methods...............................................................................................................................8

Results. .............................................................................................................................................................8

Land Cover.............................................................................................................................................8

Land Use.................................................................................................................................................9

Population ............................................................................................................................................11

Residents.....................................................................................................................................11

Employees...................................................................................................................................15

Dependents.................................................................................................................................16

Public Venues.............................................................................................................................18

Economic Assets.................................................................................................................................20

Critical and Essential Facilities.........................................................................................................24

Composite Indices of Exposure and Sensitivity.............................................................................25

Statistical Relationship to Land Cover ............................................................................................27

Summary........................................................................................................................................................28

Acknowledgments.......................................................................................................................................29

References Cited..........................................................................................................................................29

Glossary.........................................................................................................................................................33

Appendix A. North American Industry Classification System .............................................................34

Appendix B. Overview of Project Database ..........................................................................................37

 Figures

1. Map of the Cascadia Subduction Zone................................................................................................2

2. Photographs of (A) the City of Manzanita, (B) the Port of Garibaldi, 

(C) the Port of Astoria, and (D) the City of Seaside...........................................................................3

3. Conceptual diagram of societal risk to disasters. ..............................................................................3

4. Map of counties and communities on the Oregon coast with land 

in the tsunami-inundation zone.............................................................................................................4

5. Maps of 2001 NOAA C-CAP land-cover data for the (A) City of Lakeside, 

(B) City of Newport, and (C) City of Seaside, Oregon.......................................................................6

6. Conceptual diagram of populations at risk from natural hazards....................................................7

7. Distribution of land-cover classes (by area) in the tsunami-inundation zone for 

(A) the entire Oregon coast, and (B) the 26 incorporated cities. ....................................................9
iv

Tables

1. Block-level demographic characteristics for residential populations in the 

Oregon tsunami-inundation zone, based on the 2000 Census.........................................................12

2. Amount and percentage of economic assets in the Oregon tsunami-inundation zone ..............16

3. Amount and percentage of dependent-population facilities in the Oregon 

tsunami-inundation zone........................................................................................................................16

4. Amount and percentage of public venues in the Oregon tsunami-inundation zone....................18

5. Amount and percentage of critical and essential facilities in the Oregon 

tsunami-inundation zone........................................................................................................................24

6. Composite exposure and sensitivity values for cities in the Oregon 

tsunami-inundation zone........................................................................................................................26

7. Statistical results comparing land data and societal assets in the Oregon 

tsunami-inundation zone........................................................................................................................28

8. Amount (A) and percentage (B) of developed land in the Oregon 

tsunami-inundation zone......................................................................................................................10

9. County-level distributions, by area, of (A) zoning and (B) land ownership

for tsunami-prone land in Oregon.......................................................................................................11

10. Number (A) and percentage (B) of residents in the Oregon 

tsunami-inundation zone......................................................................................................................13

11. Percentage of residential population in the tsunami-inundation zone that is 

(A) residents over 65 years in age, (B) female-headed households, with 

children, no spouse present, and (C) renter-occupied households.............................................15

12. Blockgroup- and tract-level demographic characteristics for residential

populations in Oregon coastal counties, based on the 2000 Census. ..........................................16

13. Number (A) and percentage (B) of employees in the Oregon 

tsunami-inundation zone......................................................................................................................17

14. Number of dependent-population facilities in the Oregon 

tsunami-inundation zone......................................................................................................................18

15. Number of public venues in the Oregon tsunami-inundation zone...............................................19

16. Number of overnight-tourist facilities in the Oregon tsunami-inundation zone..........................19

17. Annual average number of visitors to coastal Oregon State Parks (1998-2003) 

illustrated (A) by the amount per State park and (B) as a percentage related 

to nearby incorporated cities ..............................................................................................................21

18. Amount (A) and percentage (B) of total tax-parcel value in the Oregon

tsunami-inundation zone......................................................................................................................22

19. Percentage of employees, by business sector, in the Oregon 

tsunami-inundation zone......................................................................................................................23

20. Comparison of normalized exposure and sensitivity indices for incorporated 

cities in the Oregon tsunami-inundation zone..................................................................................25

21. Frequency histogram of the sum of normalized exposure and sensitivity 

indices for incorporated cities in the Oregon tsunami-inundation zone......................................25

22. Sum of normalized exposure and sensitivity indices for incorporated cities 

in the Oregon tsunami-inundation zone.............................................................................................27

23. Scatter-plots comparing the amounts (A) and percentages (B) of land and 

of employees for incorporated cities in the Oregon tsunami-inundation zone...........................28
By Nathan Wood

Abstract

Evidence of past events and modeling of potential future 

events suggest that tsunamis are significant threats to Oregon 

coastal communities. Although a potential tsunami-inundation 

zone from a Cascadia Subduction Zone earthquake has been 

delineated, what is in this area and how communities have 

chosen to develop within it have not been documented. A 

vulnerability assessment using geographic-information-system 

tools was conducted to describe tsunami-prone landscapes on 

the Oregon coast and to document city variations in developed 

land, human populations, economic assets, and critical facilities relative to the tsunami-inundation zone. Results indicate 

that the Oregon tsunami-inundation zone contains approximately 22,201 residents (four percent of the total population in 

the seven coastal counties), 14,857 employees (six percent of 

the total labor force), and 53,714 day-use visitors on average 

every day to coastal Oregon State Parks within the tsunamiinundation zone. The tsunami-inundation zone also contains 

1,829 businesses that generate approximately $1.9 billion in 

annual sales volume (seven and five percent of study-area 

totals, respectively) and tax parcels with a combined total 

value of $8.2 billion (12 percent of the study-area total). 

Although occupancy values are not known for each facility, 

the tsunami-inundation zone also contains numerous dependent-population facilities (for example, adult-residential-care 

facilities, child-day-care facilities, and schools), public venues 

(for example, religious organizations and libraries), and critical facilities (for example, police stations). Racial diversity 

of residents in the tsunami-inundation zone is low, with 96 

percent identifying themselves as White, either alone or in 

combination with one or more race. Twenty-two percent of the 

residents in the tsunami-inundation zone are over 65 years in 

age, 36 percent of the residents live on unincorporated county 

lands, and 37 percent of the households are renter occupied. 

The employee population in the tsunami-inundation zone 

is largely in accommodation and food services, retail trade, 

manufacturing, and arts and entertainment sectors.

Results indicate that vulnerability, described here by 

exposure (the amount of assets in tsunami-prone areas) and 

sensitivity (the relative percentage of assets in tsunami-prone 

areas) varies considerably among 26 incorporated cities in 

Oregon. City exposure and sensitivity to tsunami hazards is 

highest in the northern portion of the coast. The City of Seaside in Clatsop County has the highest exposure, the highest 

sensitivity, and the highest combined relative exposure and 

sensitivity to tsunamis. Results also indicate that the amount 

of city assets in tsunami-prone areas is weakly related to the 

amount of a community’s land in this zone; the percentage 

of a city’s assets, however, is strongly related to the percentage of its land that is in the tsunami-prone areas. This report 

will further the dialogue on societal risk to tsunami hazards 

in Oregon and help identify future preparedness, mitigation, 

response, and recovery planning needs within coastal cities 

and economic sectors of the state of Oregon.

Introduction

The 2004 Sumatra-Andaman earthquake and tsunami 

devastated communities throughout the Indian Ocean and 

demonstrated to the world how tsunamis are significant threats 

to the safety, security, economic well-being, and natural 

resources of many coastal communities. Historical and geologic evidence suggest that the Oregon coast has experienced 

similar large-magnitude tsunamis and is likely to experience 

more (Heaton and Snavely, 1985; Heaton and Hartzell, 1987; 

Lander and Lockridge, 1989; Atwater and others, 1995; Satake 

and others, 1996; Atwater and Hemphill-Haley, 1997; Clague, 

1997; Jacoby and others, 1997; Peters and others, 2001; Priest 

and others, 2001; McMillan and Hutchinson, 2002; Leonard 

and others, 2004; Atwater and others, 2005). 

The Oregon coast is susceptible to two types of tsunamis 

—those generated by distant earthquakes on the seismically 

active Pacific Ocean margin and those generated by local 

earthquakes within the Cascadia subduction zone. A distantearthquake example is the tsunami associated with the 1964 

magnitude 9.2 earthquake in the eastern Aleutian-Alaska 

subduction zone that inundated the Oregon coast approximately 4 hours after initial ground shaking in Alaska (Landers 

and Lockridge, 1989). A more significant tsunami threat for 

coastal communities is associated with local earthquakes emanating along the Cascadia Subduction Zone (CSZ), the interface of the North America and Juan de Fuca tectonic plates 

that extends more than 1,000 kilometers from northern California to southern British Columbia (Rogers and others, 1996; 

Variations in City Exposure and Sensitivity 

to Tsunami Hazards in Oregon
BRITISH

COLUMBIA

OREGON

WASHINGTON

CANADA

UNITED

STATES

North

America

Plate

Juan

de Fuca

Plate

Pacific

Plate

Cascadia

Subduc tion Zone

CALIFORNIA

131 128 125 122

45

41

49

51

47

43

Gorda

Plate

Pacific

Ocean

o o o o

o

o

o

o

o

o

0 100

KILOMETERS

N

2 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

fig. 1). Based on geologic evidence, the CSZ has ruptured and 

created tsunamis 13 times in the past 7,600 years and has a 

considerable range in recurrence intervals, from as little as 140 

years between events to more than 1,000 years (Atwater and 

others, 1995; Atwater and Hemphill-Haley 1997; Goldfinger 

and others, 2003; Kelsey and others, 2002; Witter and others, 

2003; Kelsey and others, 2005). The last CSZ-related tsunami 

is believed to have occurred on January 26, 1700 (Satake and 

others, 1996; Atwater and others, 2005), and researchers predict a 10 to 14 percent chance that another could occur in the 

next 50 years (Petersen and others, 2002). Future CSZ-related 

earthquakes have been predicted to be magnitude 8 or greater 

and could subject Oregon coastal communities to intense 

ground shaking, subsidence, landslides, and liquefaction of 

unconsolidated sediments. In addition, a series of tsunami 

waves possibly 8 meters or higher are predicted to inundate 

the Oregon coast in tens of minutes after initial ground shaking in a magnitude 8 or larger earthquake (Myers and others, 

1999; Priest and others, 2001; Geist, 2005; Cascadia Regional 

Earthquake Workgroup, 2005). 

To reduce tsunami risk in Oregon and other western 

States, the U.S. National Tsunami Hazard Mitigation Program, 

a State-Federal partnership, has supported several hazard 

assessment, warning guidance, and mitigation efforts (Bernard, 2005). Oregon hazard assessments include a series of 

tsunami-inundation maps and tsunami-evacuation brochures 

(Oregon Department of Geology and Mineral Industries, 2007) 

created with modeling support provided by the Tsunami Inundation Mapping Effort (TIME) Center (Gonzales and others, 

2005b). Tsunami-warning efforts include a network of deepocean tsunami detection stations (Gonzales and others, 2005a), 

enhancements to existing tsunami-warning centers (Darienzo 

and others, 2005; McCreery, 2005; Titov and others, 2005), 

evacuation signage (Priest and others, 1996), and use of the 

National Oceanic and Atmospheric Administration (NOAA) 

Weather Radio “All-Hazards Alert Broadcast” warning system 

(Crawford, 2005). Mitigation efforts include educational 

materials to raise awareness of the potential of CSZ-related 

tsunamis (Priest and others, 1996; Connor, 2005), to improve 

evacuation procedures (Dengler, 2005), and to promote landuse strategies that reduce tsunami risk (Eisner, 2005; JonientzTrisler and others, 2005).

Although much has been done to improve our understanding of tsunami hazards and to develop regional warning systems and awareness programs, less has been done to 

understand community vulnerability to these hazards, specifically the potential impacts on people and infrastructure (U.S. 

Government Accountability Office, 2006). Community vulnerability, defined as the attributes of a human-environmental 

system that increase the potential for hazard-related losses or 

reduced performance, is primarily determined by how communities occupy and use hazard-prone land. Along the Oregon 

coast, use of tsunami-prone land varies considerably, including low-density residential development (fig. 2A), commercial 

ports (fig. 2B), industrial warehouses (fig. 2C), and high-occupancy hotels (fig. 2D). These land-use variations influence 

Figure 1. Map of the Cascadia Subduction Zone (adapted from 

U.S. Geological Survey, 2007). 

vulnerability, often characterized by the exposure, sensitivity, 

and resilience of a community and its assets in relation to 

hazards (Turner and others, 2003). A tsunami may cause damage to buildings or injure people, but the cumulative choices a 

community makes with regards to land use and its willingness 

to develop risk-reduction strategies (for example, education 

programs and evacuation training) before an extreme event 

occurs set the stage for these losses (Mileti, 1999; Weichselgartner, 2001; Wisner and others, 2004). The risk of future tsunami 

disasters is therefore a function of predicted hazards and the 

vulnerable human systems that occupy hazardous areas (fig. 3). 

Although not as extensive as research on past and potential tsunamis, some research has been done to understand societal vulnerability to CSZ-related tsunami hazards in Oregon. 

Charland and Priest (1995) indicate that many critical facilities in Oregon coastal communities are at significant risk of 

collapse should a CSZ-related earthquake and tsunami occur. 

Wood and Good (2004) show that residential populations are 

low in tsunami-prone areas of one Oregon port and harbor 

community; whereas the high number of major employers 

and tourist attractions indicate a tsunami could result in high 

employee and tourist fatalities. Countering the traditional 

emphasis on engineering-based approaches to assess vulnerability, Wood and others (2002) show that non-spatial aspects of 
A

B

C

D

Risk 

of 

Disaster

Natural Hazard Vulnerable System

Exposure, Sensitivity 

and Resilience of: Potential Catastrophic 

and Chronic Physical Events

Past Recurrence Intervals

Future Probability

Speed of Onset

Magnitude

Duration

Spatial Extent

Population

Economy

Land Use and Development

Infrastructure and Facilities

Cultural Assets

Ecosystem Goods and Services

Ability, Resources 

and Willingness to:

Mitigate

Prepare

Respond

Recover

Introduction 3

community vulnerability, such as poor interagency communication and low hazard awareness of residents, were of greater 

concern to members of an Oregon port and harbor community 

than the loss or damage of any specific structure that could 

be mapped or studied. Results of a 2001 perception study of 

Oregon and Washington coastal communities indicate that 

comprehension of earthquake and tsunami hazards and of societal vulnerability to these threats varied considerably among 

survey participants and that few local risk-reduction actions 

had been implemented (Wood and Good, 2005). Finally, a 

statewide seismic needs assessment indicates that there are 

numerous Oregon education and emergency-services buildings 

(for example, fire and police stations) in areas of high tsunami 

risk (Lewis, 2007). 

To complement these efforts, research describing the 

communities that occupy tsunami-prone land along the Oregon 

coast is needed. Although all communities here are vulnerable 

to predicted tsunami hazards, the extent of the vulnerability 

in each community will vary, depending on the distribution of 

socioeconomic assets. Determining how communities currently vary in their vulnerability to tsunami hazards will help 

community members, emergency managers, and private relief 

organizations understand potential societal impacts of CSZrelated tsunamis. This knowledge will help them determine 

if regional mitigation, preparedness, response, and recovery 

strategies need to be augmented with site-specific efforts that 

reflect local conditions and needs, such as targeted education 

programs, evacuation procedures for special-needs populations, or continuity planning for particular business sectors. 

Land-use planners and coastal resource managers will find 

this information valuable in their efforts to manage the use of 

tsunami-prone land.

Purpose and Scope

The purpose of this report is to describe tsunami-prone 

landscapes and document how cities vary in vulnerability to 

CSZ-related tsunamis on the Oregon coast. Data presented 

in this report include city-level descriptions and comparisons 

Figure 2. Photographs of (A) the City of Manzanita, (B) the Port 

of Garibaldi, (C) the Port of Astoria, and (D) the City of Seaside. 

(USGS photographs by Nathan Wood.)

Figure 3. Conceptual diagram of societal risk to disasters.
Toledo

Bandon

Yachats

Seaside

Newport

Astoria

Waldport

Lakeside

Gearhart

Coos Bay

Warrenton

Manzanita

Garibaldi

Depoe Bay

Brookings

North Bend

Gold Beach

Port Orford

Lincoln City

Cannon Beach

OREGON

P a c i f i c O c e a n

Florence

Curry

County

Coos

County

Douglas County

Lane County

Lincoln County

Clatsop

County

Tillamook County

0 50km

Rockaway Beach Wheeler

Nehalem

Bay City

Tillamook

WASHINGTON

Cape Meares Oceanside Netarts

Pacific City

Neskowin

Winchester Bay

Barview

Harbor

Bunker Hill

Lincoln Beach

Rose Lodge

Cloverdale

CALIFORNIA

Incorporated city

Unincorporated town

County

N

4 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

of the amount and percentage of assets in tsunami-prone 

areas, based on the distribution of developed land, human 

populations, economic assets, and critical facilities relative 

to a CSZ-related tsunami-inundation zone. Variations in city 

vulnerability to tsunamis are based on the presence of assets 

in tsunami-prone areas; results are not engineering-based loss 

estimates for any particular facility. 

Certain vulnerability aspects were considered outside the scope of this report, including potential ecosystem 

impacts, risk perceptions, social capital (Alwang and others, 

2001; Pelling, 2002) and resilience, defined as the ability to withstand, absorb, adapt to, and recover from losses 

(Turner and others, 2003). It also does not seek to identify 

the underlying determinants of the variations in community 

vulnerability (Wisner and others, 2004). The report focuses 

exclusively on tsunamis on the Oregon coast and does not 

discuss the additional hazards associated with a CSZ earthquake, including ground shaking, liquefaction, subsidence, 

and landslides.

To understand the potential impacts of future tsunamis 

in Oregon, policymakers, managers, and private citizens must 

understand the current vulnerability of communities that 

occupy tsunami-prone land. This analysis is intended to serve 

as a foundation for additional risk-related studies and to help 

community members and public-sector managers to develop 

mitigation, preparedness, response, and recovery strategies 

that are tailored to local needs. This information will also 

help county, State, and Federal policymakers (either in the 

emergency-management or land-use arena) decide where and 

for whom to prioritize risk-reduction strategies.

Study Area 

This study focuses on the seven coastal counties of 

Oregon, including Clatsop, Tillamook, Lincoln, Lane, Douglas, Coos, and Curry, and the 26 incorporated cities (based on 

2003 city-limit boundaries) within them that intersect a statewide tsunami-inundation zone (Oregon Geospatial Enterprise 

Office, 2007) (fig. 4). There are also 12 unincorporated towns 

along the Oregon coast, as delineated by census-designatedplace boundaries (U.S. Census Bureau, 2007a), that intersect the tsunami-inundation zone (fig. 4); however, because 

emergency services and land-use planning for these towns are 

performed by county offices, results related to unincorporated 

towns are reported at the county level.

The tsunami-inundation zone was developed by the 

Oregon Department of Geology and Mineral Industries 

(DOGAMI) to support Oregon Revised Statutes (ORS) chapter 

455, sections 446 and 447, which are provisions passed in 

1995 to limit the construction of essential facilities in tsunamiinundation zones (Priest, 1995; Olmstead, 2003). Based on 

geologic evidence of past events and tsunami-propagation 

modeling, this tsunami-inundation zone delineates the upper 

limit of area expected to be covered by flood water from a 

tsunami caused by a magnitude 8.8 CSZ earthquake (Priest, 

1995). The maximum run-up estimated in Priest (1995) was 

considered a reasonable inundation boundary for implementation of ORS 455 but new modeling coupled with improved 

understanding of earthquake sources and the role of local 

splay faults and areas of concentrated fault slip in amplifying 

tsunami heights suggest worst-case inundation scenarios that 

exceed the ORS 455 zone (Witter and others, 2007; Zhang and 

others, 2007; Priest, written communication, 2007). Higherresolution inundation models and zones have been developed 

for select Oregon estuaries (for example, Wong and others, 

2006); however, the ORS 455 tsunami-inundation zone is used 

here because it is a regional study. The impacts of a CSZrelated tsunami described in this report are based on the ORS 

455 inundation zone and are therefore conservative estimates.

Figure 4. Map of counties and communities on the Oregon coast 

with land in the tsunami-inundation zone.
Methods and Data 5

Methods and Data

To describe tsunami-prone landscapes and compare city 

vulnerability to tsunamis on the Oregon coast, geographicinformation-system (GIS) tools were used to integrate 

publicly available hazard and socioeconomic data. Vulnerability calculations and comparisons consider city exposure 

and sensitivity based on the distribution of developed land, 

populations (residential, employee, and tourists), economic 

assets, and critical facilities. These assets are chosen based 

on the data U.S. jurisdictions are encouraged to collect as 

they develop State and local mitigation plans (Federal Emergency Management Agency, 2001), a requirement to qualify 

for funds under the U.S. Hazard Mitigation Grant Program in 

accordance with the Disaster Mitigation Act of 2000, Public 

Law 106-390. Exposure is based on the amount of an asset 

(for example, the number of residents) within a tsunamiinundation zone of a city. Sensitivity is defined as the relative 

impact of losses to an entire community (for example, the 

percentage of a community’s workforce in a tsunami zone) 

and is calculated by dividing the amount of an asset in a 

tsunami-inundation zone by the total amount of that asset 

in a city. For example, if community A has 100 businesses 

in a tsunami-inundation zone (representing 10 percent of 

the local economy) and community B has 30 businesses in 

a tsunami- inundation zone (representing 90 percent of the 

local community), then community A has a higher economic 

exposure because it has more businesses in the tsunami zone, 

but community B is more economically sensitive because it 

has a higher proportion of its businesses in the tsunami zone. 

Exposure and sensitivity values based on various socioeconomic assets are reported for each city and then combined 

to create overall indices of city exposure and sensitivity to 

tsunami hazards. Prior to analysis, all geospatial data were 

processed to share the same datum (North American Datum 

of 1983) and projection (Oregon Lambert) of data within the 

Oregon Geospatial Data Clearinghouse (2007). Spatial analysis of vector data (for example, business points and tax-parcel polygons) focused on determining if points or polygons 

are inside the tsunami-inundation-zone polygons. Slivers of 

polygons that overlap administrative boundaries and tsunami 

zones are taken into account during analysis and final values 

are adjusted proportionately.

Land Data

The first step in understanding societal vulnerability is 

to determine the type of land-use and land-cover (LULC) 

in the tsunami-inundation zone. County-level descriptions 

of land use in the tsunami-inundation zone are based on 

regional zoning and land-ownership data (Oregon Geospatial Enterprise Office, 2007); local land-use information is 

not digitally available for all segments of the study area. 

Land-cover descriptions of the tsunami-inundation zone are 

based on data compiled in 2001 by the National Oceanic 

and Atmospheric Administration’s (NOAA) Coastal Change 

Analysis Program (C-CAP). C-CAP land-cover data is 

nationally standardized for the coastal regions of the United 

States (NOAA CSC, 2007; Dobson and others, 1995) and 

is part of the National Land Cover Database (NLCD) effort 

through the interagency Multi-Resolution Land Characteristics (MRLC) Consortium (Homer and others, 2004; Loveland 

and Shaw, 1996). NLCD products, including LULC, percent 

impervious cover, and percent canopy cover, are automatically derived from Landsat Thematic Mapper (TM) and 

Enhanced Thematic Mapper Plus (ETM) digital satellite 

imagery, which is produced at a 30-meter horizontal resolution. C-CAP data generated before 2005 have 22 land-cover 

classes and have a reported accuracy standard of 85 percent 

(Dobson and others, 1995). 

One set of societal vulnerability indicators assessed in 

this study is the amount and percentage of developed land 

relative to the tsunami-inundation zone in each incorporated 

city and for the unincorporated portions of each county. Vulnerability is assumed to increase with greater amounts and 

percentages of developed land in tsunami-prone areas. Developed land is represented by low-intensity developed and 

high-intensity developed classes in C-CAP data generated 

before 2005. Low-intensity developed cells contain 50 to 

79 percent of constructed surfaces, are a mix of constructed 

and vegetated surfaces, and typically represent small buildings, streets, and cemeteries. High-intensity developed cells 

contain more than 80 percent of constructed surfaces, have 

little or no vegetation and typically represent heavily built-up 

urban centers, large buildings, and large paved surfaces, such 

as runways and interstate highways (Dobson and others, 

1995). Since 2005, a medium-intensity developed class was 

added; however, the pre-2005 classification scheme is used 

to allow for comparisons to tsunami assessments already 

completed in other States (Wood and others, 2007). Based 

on the distribution of land-cover cells classified as high- and 

low-intensity developed in relation to the tsunami-inundation 

zone, the majority of developed land is outside of the zone 

in the cities of Lakeside (fig. 5A) and Newport (fig. 5B), but 

inside the zone in the City of Seaside (fig. 5C). 

Population Data

Another aspect of community vulnerability is the size 

of local populations (including residents, employees, and 

dependents) and tourist populations that may be at risk from 

tsunamis (fig. 6). The number and type of residents in the 

tsunami-inundation zone were determined using demographic 

data from census blocks (a geographic unit) of the 2000 U.S. 

Census (U.S. Bureau of Census, 2000). In addition to total 

population and households, demographic information for 

each city is summarized relating to ethnicity (Hispanic or 

Latino), race (American Indian and Alaska Native, Asian, 

Black or African American, Native Hawaiian and other Pacific 

Islander, and White—all alone or in combination with one 
1 km 1 km

1 km

Pacific

Ocean

Pacific

Ocean

Pacific

Ocean

Bare Land

Forest

Wetland

Grassland and Scrub/Shrub

High-Intensity Developed

Low-Intensity Developed

Tsunami-Inundation Line

City Limit

Land-Cover Class

A City of Lakeside, Oregon B City of Newport, Oregon C City of Seaside, Oregon

N N

N

6 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

or more other races), age (populations under 5 and over 65 

years in age), gender (female population and female-headed 

households with children and no spouse present), and tenancy 

(renter-occupied households). Census block-group and tract 

data are summarized at the county level, regardless of the 

tsunami-inundation zone, to provide additional insight on local 

conditions if a disaster were to occur and not at the hazardlevel due to the size differences between inundation polygons 

and the larger census units.

Other local at-risk populations include employees and 

dependents. The number and types of employees in the study 

area (excluding seasonal labor) were determined using the 

2005 InfoUSA Employer Database. Because no fieldwork was 

conducted to verify business locations, results based on the 

Employer Database throughout this report should be considered first approximations and developed to generate discussions for additional, more-detailed studies. Dependent populations are defined as individuals who temporarily reside in 

facilities and would require assistance to evacuate and recover. 

North American Industry Classification System (NAICS) 

codes for businesses in the InfoUSA Employer Database 

(appendix A) were used to identify the following dependentpopulation facilities: 

•	 Medical facilities, including hospitals, psychiatrics and 

substance abuse hospitals, mental health services and 

psychiatric treatment facilities, pregnancy counseling, 

clinics, and physician offices;

•	 Adult residential care, including adult care facilities, hospices, nursing homes, rest homes, retirement 

communities, adult homes, senior citizens services, 

residential care homes, group homes, foster care, and 

adult day care centers;

•	 Child day care, including large babysitting facilities, 

childcare centers, pre-schools and nursery schools 

(both public and private); 

•	 Schools, including religious schools, public and private 

schools, schools with special academics, and homeschooling centers; and

•	 Correctional facilities, including State and Federal 

facilities. 

Tourists are another significant population in coastal communities and can often outnumber residents and employees 

in tsunami-prone areas (Wood and Good, 2004). Because no 

consistent census count for tourists exists, public venues and 

Oregon State Park visitor data are used. Businesses that likely 

attract nonresidents are considered public venues and are identified using NAICS codes for businesses in the 2005 InfoUSA 

Employer Database (appendix A). Public venues include aquariums, botanical gardens, casinos, colleges and universities, historical places, libraries, museums, parks, religious organizations, 

shopping centers and malls, sporting facilities, theaters (including live and cinematic), and zoos. Data on the annual-average 

number of visitors from 1998 to 2003 for Oregon State Parks 

Figure 5. Maps of 2001 NOAA C-CAP land-cover data for the (A) City of Lakeside, (B) City of Newport, and (C) City of Seaside, Oregon.
Populations at Risk

- Adult Residential Care

- Child Day-Care Centers

- Correctional Facilities

- Hospitals

- Nursing Homes

- Outpatient Care Centers

- Psychiatric Hospitals

- Schools

Varying Needs

Based On:

- Age

- Economic Status

- Education

- Family Structure

- Gender

- Level of Dependence 

 on Social Services

- Ability to Speak 

 Primary Language

- Occupation

- Race/ethnicity

- Renter or homeowner

Local

- Bed & Breakfasts

- Cabin Rentals

- Campgrounds

- Camps

- Health Resorts

- Hostels

- Hotels

- Inns

- Resorts

- RV Parks

- Aquariums/Zoos

- Casinos

- Colleges

- Festivals

- Historical Places

- Libraries

- Museums

- Parks

- Religious Services

- Shopping Centers

- Spectator Sports

- Theaters

Tourist

Resident Employee Dependent Public Venues Lodging

- Permanent

- Seasonal Worker

Methods and Data 7

(Oregon State Parks, 2005, unpublished data) are also used to 

approximate the number of visitors along the Oregon coast that 

may be in the tsunami-inundation zone. To gauge the potential 

impact to communities in the event of a tsunami, coastal parks 

are coded by the incorporated city closest to them (based on 

road distance). The number of annual visitors to nearby parks is 

summed for each city and a relative percentage is calculated for 

each city based on the overall sum of annual visitors to parks on 

the Oregon coast. These calculations are done to approximate 

which cities and their services (for example, police and hospitals) could be most impacted by high casualties in nearby parks. 

This approach also indicates the number of day tourists that may 

be in or near a city should a tsunami occur; for example, visitors 

to a State park may have lunch or shop in a nearby town.

Economic Data

Economic analyses for this study focus on two elements 

of the coastal economy—tax base and business community. 

Tax base, as represented by county parcel values, is an attribute 

of societal vulnerability because cities and counties rely on 

property taxes for local services. Communities can typically 

expect disaster-relief aid from State and Federal sources, as well 

as from nonprofit organizations and private donations, but funds 

for longer-term recovery and the restoration of county services 

typically come from revenue generated by property taxes. If an 

extreme event destroys property, land values will be reassessed 

at some point and likely lowered, the city tax base will shrink, 

and a city may have a harder time with disaster recovery. Taxparcel databases were provided by all seven counties in 2006 

and parcel-polygon attributes include property value and content 

value (both in 2006 U.S. dollars). 

Potential impacts to the business community in each 

city and county are determined by calculating the amount 

and percentage of businesses, employees, and generated sales 

volumes in the tsunami-inundation zone using data from the 

InfoUSA Employer Database. Businesses in the tsunami-inundation zone with “P.O. box” mailing addresses (four percent 

of the database) were counted in the city- and county-totals, 

because point locations were for the P.O. box and not the 

actual business. Economic conditions, such as the dominance 

of specific sectors, are based on employee distributions, an 

indicator routinely used by the private and public sector to 

evaluate economic health and market trends (Marshall, 1989; 

Bureau of Labor Statistics, 2007a).

Critical-Facilities Data 

Certain facilities are considered critical for short-term 

response and others are considered essential for long-term 

recovery of a community following a disaster. As a starting 

point for discussing critical and essential facilities along the 

Oregon coast, certain facilities were identified using NAICS 

codes in the InfoUSA Employer database (appendix A). 

Critical facilities include those used for public safety purposes (civil-defense facilities, fire stations, national-security 

facilities, police stations, and radio and television stations), 

medical services (ambulances, hospitals, outpatient-care centers, and physician offices), and infrastructure maintenance 

(electric, public-works, natural-gas, waste-water, and water 

Figure 6. Conceptual diagram of populations at risk from natural hazards.
8 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

and sewer facilities). Essential facilities include those that 

provide for basic necessities (banks and credit unions, gas 

stations, and grocery stores) or serve government functions 

(courts and legal offices, government offices, internationalaffairs offices, and U.S. Post Offices).

Composite Indices of Exposure and Sensitivity

To compare city and county vulnerability, composite 

exposure and sensitivity indices were developed for the 33 

geographic units (26 incorporated cities and the unincorporated 

land in the 7 counties) and are based on the amounts and percentages, respectively, of five categories–developed lands, residents, employees, public venues and hotel facilities, and total 

tax-parcel values. Composite indices of exposure and sensitivity 

were developed by first normalizing values in the five categories 

to the maximum value found within that category. Normalizing 

data to maximum values creates a common data range of zero to 

one for all five categories and is a simple approach for enabling 

comparisons among disparate datasets. The five normalized values are then summed, resulting in one final score ranging from 

zero to five for each of the 33 geographic units. These are relative scores developed to compare the 33 geographic units and 

have no stand-alone meaning for an individual city or county. 

A final score integrating the composite exposure and sensitivity 

values is determined for each of the 33 geographic units by first 

normalizing each of the composite scores to maximum values, 

creating common data ranges of zero to one for each of the 

indices and minimizing any weighting bias between the indices. 

Normalized values are then added with no additional weighting, 

resulting in a final combined score ranging from zero to two.

Statistical Methods

Descriptive statistics are used to summarize general trends 

and identify extremes in city exposure and sensitivity. Several 

datasets have non-normal distributions, based on Shapiro-Wilk 

(W) normality tests at α = 0.05 (Zar, 1984); therefore, median 

and third-quartile (75th percentile) values are reported instead 

of mean values and their standard errors, which are commonly 

used to describe normal distributions. One hypothesis that 

arises in the process of documenting these variations is that the 

amount of city assets and the amount of city land in the tsunami-inundation zone are related; that is, more community land 

in the tsunami zone means there are more community assets in 

the zone. To test this hypothesis, a series of linear-regression 

analyses were conducted between land-area data and several 

city assets, including developed lands (lands classified as either 

low- or high-intensity developed), residents, employees, total 

parcel values, and public venues and hotels. Linear regressions 

were conducted for exposure values (the amounts of city land 

and assets in the tsunami-inundation zone) and for sensitivity 

values (the percentages of city land and assets in the tsunamiinundation zone) to determine if the amount and percentage of 

city land in tsunami-prone areas are significant factors in the 

distribution of city and county assets. The independent variable 

was the amount or percentage of land, regardless of land-cover 

class, within city and county limits. The dependent variables 

were the amount or percentage of assets within city and county 

limits. The null hypothesis in each of the analysis-of-variances 

tests is that no statistically significant relationship exists. Significance is assumed if calculated Fisher (F) values comparing the 

mean squares of the linear regression and residuals are greater 

than 4.17, which represents the critical F-value for a one-tailed 

test at α = 0.5 and 31 degrees of freedom (Zar, 1984). Tests 

are done with an assumption of normality in the distribution of 

residuals (or homoscedasticity), based on a graphical examination of residual plots (Zar, 1984). In addition to F-values, the 

Pearson product-moment-correlation coefficient (r), the square 

of the Pearson product-moment correlation (r2

), and p-values 

are calculated. A significant statistical relationship between land 

area and the specific asset is assumed if a p-value is less than 

0.05. A p-value of greater than 0.05 suggests that differences in 

the variances of the populations being compared (for example, 

land-area and number of residents) are too large to propose that 

a relationship exists.

Results

Descriptions of tsunami-prone landscapes in Oregon 

focus on land use and land cover, populations, economic 

assets, and critical and essential facilities. Third quartiles, also 

known as 75th-percentiles, are noted on bar-graphs in each 

section so that readers can easily identify which cities are in 

the top 25 percent of exposure and sensitivity calculations and, 

therefore, can be considered the most vulnerable in a category. 

Data on cities and counties are also provided in an accompanying database (appendix B).

Land Cover

The distribution of land-cover types (by area) in the 

tsunami-inundation zone was determined for the entire Oregon 

coast (fig. 7A) and for land just within the 26 incorporated cities (fig. 7B) by integrating 2001 C-CAP data, city and county 

boundaries, and the ORS 455 boundary. Results indicate 

that 95 percent of the land in the tsunami-inundation zone 

along the Oregon coast is classified as undeveloped (neither 

high- nor low-intensity developed) (fig. 7A). Wetland-related 

classes were the most common type of land-cover found in the 

tsunami-inundation zone (56 percent), followed by grasslands 

(15 percent) and bare land (14 percent). For land just in the 26 

incorporated cities (fig. 7B), seventy-eight percent of land is 

classified as undeveloped, with most land classified as wetland 

(44 percent) or grassland (14 percent). 

Although the majority of tsunami-prone land in Oregon 

is not classified as developed, these undeveloped areas can 

attract recreationists (both local residents and tourists) who 

could be impacted by a CSZ-related tsunami. Past studies 
Wetland

(56%)

Bare

Land

(14%)

Grassland

(15%)

Scrub/

shrub

 (2%)

Low-Intensity 

Developed (4%)

High-Intensity

Developed (1%)

Scrub/

shrub

 (3%)

Wetland

(44%)

Bare

Land

(8%) Grassland

(14%)

Forest (9%)

LowIntensity 

Developed 

(16%)

High-Intensity Developed (6%) 

Forest

 (8%)

A

B

Results 9

Figure 7. Distribution of land-cover classes (by area) in the 

tsunami-inundation zone for (A) the entire Oregon coast, and (B) 

the 26 incorporated cities.

(Wood and others, 2002; Wood and Good, 2004) have shown 

that tourists can dominate the daily population of coastal 

communities and represent a significant tsunami vulnerability 

issue. In addition, damage or loss of natural areas due to a 

tsunami could have societal consequences because these areas 

provide natural resources, critical habitats, and ecosystem 

services. For example, tsunami-related deposition of sediment and debris in coastal wetlands could impact ecosystem 

functions in these areas, which are critical habitats for juvenile 

fish. The subsequent losses to fisheries could impact the Oregon fishing industry, an industry that contributed $283 million 

to the Oregon economy in 2003 (Radtke and Davis, 2004).

Focusing on the distribution of developed land, results 

indicate that the amount (fig. 8A) and percentage (fig. 8B) 

of C-CAP landcover cells classified as either low- or highintensity developed in the tsunami-inundation zone vary within 

the cities and unincorporated county lands along the Oregon 

coast (note: jurisdictions on the y-axis are arranged in descending geographic order from the City of Astoria in the north to 

the unincorporated land of Curry County in the south). Third 

quartiles for the amount and percentage of developed land in 

cities and the unincorporated county lands are 0.73 km2

 and 27 

percent, respectively, suggesting that most jurisdictions have 

low amounts and percentages of developed land in the tsunamiinundation zone. Certain cities are well above the third quartile 

in both categories, such as the City of Seaside with 2.57 km2

 of 

developed land in hazard-prone areas, representing 87 percent 

of its developed land. The next highest amount of developed 

land in tsunami-prone areas is in the rural sections of Tillamook 

County, indicating potential impacts to the unincorporated 

towns of Cape Meares, Cloverdale, Oceanside, Neskowin, 

Netarts, and Pacific City (fig. 4).

Results indicate that cities either have high exposure 

(amounts) or high sensitivity (percentages), but rarely both. 

Some cities, such as Newport and North Bend, have relatively 

high amounts of developed land in the tsunami-inundation zone 

(0.83 km2

 and 0.86 km2, respectively) that represent a small 

percentage of total city land (15 and 16 percent, respectively). 

Other cities, such as Gearhart, Cannon Beach, Waldport, and 

Yachats, have relatively low amounts of developed land in 

tsunami-prone areas (less than 0.5 km2), but this land represents 

the majority of their development (greater than 50 percent in the 

four cities). Only the cities of Warrenton and Seaside exceed 

third-quartile values in both exposure and sensitivity.

Land Use

The distribution of land uses (by area) in the tsunamiinundation zone was determined for the seven coastal counties 

using zoning and ownership data to provide county, State, and 

Federal officials additional context on potential response and 

recovery issues. For example, tsunami-prone land zoned for 

nonurban uses (for example, parks and recreations, forestry, 

coastal, natural resources) suggest that initial response efforts 

will likely center on tourist populations in undeveloped areas 

and not on damaged infrastructure or buildings. This may 

be the case in Lane and Douglas Counties, where 69 and 91 

percent, respectively, of the tsunami-prone land is zoned parks 

and recreation (fig. 9A). The highest percentages of tsunamiprone areas zoned as urban, and therefore greater development, are in the northern half of the Oregon coast, including 

Clatsop County (48 percent), Lincoln County (34 percent), 

and Tillamook County (21 percent). 

The majority of tsunami-prone land along the Oregon 

coast is privately owned (fig. 9B), with the highest values in 

Curry County (96 percent), Lincoln County (93 percent), and 

Clatsop County (91 percent). In counties with high private 

land ownership, public officials will have to balance county 

and State needs with the rights of private land owners during the recovery process. Douglas County is the only county 

where the majority of tsunami-prone land is not privately 

owned; the small amount of its coastal shoreline (approximately 28 kilometers from north to south) is owned primarily 

by the Federal Government (70 percent) or the State of Oregon 
Percentage of Developed Land 

in Tsunami-Inundation Zone

0% 50% 100%

3rd Quartile 

(27%)

0 1.5 3.0

Amount of Developed Land in

Tsunami-Inundation Zone (km )2

3rd Quartile 

(0.73 km ) 2

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

A B

10 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

Figure 8. Amount (A) and percentage (B) of developed land in the Oregon tsunami-inundation zone.
Douglas

Lane

Curry

Coos

13%

8%

14%

34% 19%

13%

26% 19%

3%

9%

39%

5%

91%

4%

5%

1%

3%

6%

12%

5%

69%

5%

16%

3%

7%

20%

34% 21%

3% 27%

21%

31%

12%

5%

Clatsop 48%

12%

5%

1%

21%

11%

2%

1%

Urban

Rural - various

Agriculture

Coastal

Forestry

Natural Resource

Park/Recreation

Public Facility

Zoning

Lincoln

Tillamook

0 25 km

91%

41%

2%

55%

4% 3%

93%

3%

17%

80%

2%

7%

96%

3% 1%

22%

4%

74%

9%

21%

70%

2%

Land Ownership

Private or 

Non-Government

County

State of Oregon

Federal 

Douglas

Lane

Curry

Coos

Clatsop

Lincoln

Tillamook

Pacific 

Ocean

0 25 km

Pacific 

Ocean

City City

A B

N N

Results 11

(21 percent). In the event of a tsunami that impacts Douglas 

County, recovery of damaged lands (for example, State park 

facilities) will take place largely within the public sector. 

Population

Residents

The tsunami-inundation zone contains 22,201 residents 

and 10,201 households (table 1), both representing 4 percent 

of totals in the seven counties. These study-area percentages, 

and all subsequent study-area percentages reported in this 

report, are low because the major population centers for Lane 

and Douglas Counties (Eugene and Roseburg, respectively) 

are not along the coast, unlike the other five counties, and are 

the biggest cities in the study area. The number (fig. 10A) and 

percentage (fig. 10B) of residents in the tsunami-inundation 

zone varies across the seven counties, with the highest values 

in the northern section of the coast. The City of Seaside has 

the highest number of residents (4,790) in the tsunami-inundation zone, while the City of Gearhart has the highest percentage (85 percent) of its residents in the tsunami-inundation 

zone. Some cities, such as Lincoln City, have a high number of 

residents in the tsunami-prone area (1,321) but these residents 

represent a low percentage (18 percent) of the town’s total 

population. The reverse is true in other cities (for example, 

Figure 9. County-level distributions, by area, of (A) zoning and (B) land ownership for tsunami-prone land in Oregon.
12 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

Cannon Beach, Rockaway Beach, Waldport, and Yachats) 

where low numbers represent high percentages. Results also 

indicate that 7,912 residents are in tsunami-prone areas outside 

of the 26 incorporated cities (representing 36 percent of all 

residents in the tsunami-inundation zone) and are primarily 

in the unincorporated portions of Lincoln (2,175), Clatsop 

(1,828), Tillamook (1,641) and Coos (1,014) Counties. 

Residents in the tsunami-prone areas of unincorporated lands 

within Tillamook County are primarily located in the unincorporated town of Pacific City (estimated population of 1,027 

residents in the 2000 Census).

Any individual occupying tsunami-prone land is vulnerable to some extent, but social-science research has demonstrated that demographic factors like age, race, gender, and 

socioeconomic status can amplify this vulnerability, thereby 

increasing the potential for losses, present unique response 

needs, or slow recovery after an extreme event (Morrow, 

1999; Ngo, 2003; Cutter and others, 2003; Laska and Morrow, 2007). Results characterizing demographic attributes of 

residents in the study area (table 1) do not imply that all individuals of a certain demographic group will exhibit identical 

behavior during or after a tsunami. Variations in local cultures 

and situations, as well as individual and community resilience, 

will influence the extent of these demographic sensitivities. 

Race and ethnicity influence individual sensitivity to 

stressors, as studies have shown that households of racial and 

ethnic minorities tend to be more vulnerable to extreme natural 

events (Morrow, 1999). This reflects not characteristics of the 

individual but of historic patterns of racial and ethnic inequalities within a society that result in minority communities which 

are more likely to have inferior public services, infrastructure, 

and building stock (Laska and Morrow, 2007) and that may 

be excluded from disaster planning efforts (Morrow, 1999). 

Minorities that speak a language other than the primary 

language of an area are also more vulnerable, as language barriers could hinder the effectiveness of awareness campaigns, 

evacuation procedures, and post-disaster recovery opportunities. Racial and ethnicity diversity is low for the tsunami-prone 

areas of the Oregon coast, where 96 percent of all residents 

in the Oregon tsunami-inundation zone identified themselves 

in the 2000 Census as White, either alone or in combination 

with one or more other races (table 1), and the percentage of 

this demographic group ranges from 91 to 100 percent within 

the cities and the unincorporated county lands. Other reported 

races for residents in tsunami-prone areas of the Oregon coast 

include Black or African American (1 percent), American 

Indian and Alaska Native (3 percent) and Native Hawaiian 

and Other Pacific Islander (less than 1 percent). The percentage of Hispanic populations in the tsunami-inundation zone 

is also low (4 percent). Race percentages do not sum to 100 

percent because individuals were able to report multiple races 

in the 2000 Census. Comparisons of the race and ethnicity of 

Table 1. Block-level demographic characteristics for residential populations in the Oregon tsunami-inundation zone, based on the 

2000 Census.

Population Tsunami-Inundation 

Zone

Study Area

Total

Tsunami-Zone 

Percentage1

Study Area 

Percentage1

Maximum City 

Percentage

Total Population 22,201 611,645 4% n/a 85%

Hispanic or Latino Population 827 26,011 4% 4% 8%

Race—White alone or in combination with one or 

more other races 21,236 578,171 96%2 95%2 100%

Race—Black or African American alone or in combination with one or more other races 118 5,594 1%2 1%2 6%

Race—American Indian and Alaska Native alone or in 

combination with one or more other races 610 19,392 3%2 3%2 7%

Race—Asian alone or in combination with one or 

more other races 322 12,552 1%2 2%2 3%

Race—Native Hawaiian and Other Pacific Islander 

alone or in combination with one or more other races 62 2,202 0%2 0%2 2%

Population under five years old 975 33,476 4% 5% 8%

Population over 65 years 4,867 97,518 22% 16% 45%

Female population 11,400 310,830 51% 51% 58%

Number of Households 10,201 250,229 4% n/a 86%

Renter-Occupied Households 3,795 86,201 37% 34% 56%

Single-Mother Households 559 15,671 5% 6% 12%

1

In-hazard percentages refer the percentage of individuals (or households for the last two rows) in the tsunami-inundation of a specific demographic category. 

Study-area percentages refer to the percentage of individuals (or households for the last two rows) in the seven coastal counties of a specific demographic category.

2

The sum of percentages by race will not sum to 100%, as individuals are able to report multiple race categories in U.S. Census Bureau reports.
Figure 10. Number (A) and percentage (B) of residents in the Oregon tsunami-inundation 

zone.

Percentage of Residents in

Tsunami-Inundation Zone

0% 50% 100%

3rd Quartile 

(18%)

0 5,000

Number of Residents in

Tsunami-Inundation Zone

3rd Quartile 

(842)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

A B

Results 13
14 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

residents in tsunami-prone areas to that of the entire study-area 

population indicate that no group is disproportionately represented in tsunami-prone areas (table 1).

Another demographic characteristic that influences an individual’s sensitivity is age (Morrow, 1999; Ngo, 2001; Balaban, 

2006; Laska and Morrow, 2007; McGuire and others, 2007). For 

example, a survey of Indonesian households impacted by the 

2004 Sumatra-Andaman tsunami demonstrated that mortality 

was highest for the youngest and oldest age groups (Rofi and 

others, 2007). Younger populations, defined here as less than 5 

years in age, often require direction and assistance to evacuate 

due to their immaturity and size. They are also prone to developing post-traumatic stress disorders, depressions, anxieties, and 

behavioral disorders as a result of their inability to comprehend 

and process effects of a disaster (Balaban, 2006). Results indicate that 4 percent of individuals in the Oregon tsunami-inundation zone are younger populations, approximately equal to 

the State percentage, and the percentage of younger populations 

in the hazard-prone areas of the 26 cities and 7 unincorporated 

county lands ranges from 0 to 8 percent (table 1). 

Older populations, defined here as residents over 65 

years in age, may also have special needs during and after 

a tsunami. Research suggests the older populations may 

require assistance in evacuation due to potential mobility and 

health issues or a reluctance to evacuate, may require special 

medical equipment at shelters (McGuire and others, 2007), 

and are more apt to lack social and economic resources to 

recover (Morrow, 1999; Ngo, 2001). Results indicate that 

22 percent of individuals in the tsunami-inundation zone 

are older populations, higher than the 16 percent for the 

entire study area. The percentage of older populations in 

tsunami-prone land of the 26 cities and 7 unincorporated 

county lands varies considerably in this study area, ranging 

from 10 percent in Bay City to 45 percent in Bandon (fig. 

11A). It may be difficult to quickly evacuate older populations from tsunami-prone areas, given their potential health 

and mobility issues and the limited time between earthquake 

ground-shaking and tsunami inundation (30 minutes in 

some communities). If a tsunami were to occur in the winter 

months, emergency shelters may not adequately protect older 

populations from exposure to low air temperatures and high 

precipitation (common during winter months on the Oregon 

coast), causing further health complications for older populations. Therefore, communities with high percentages of older 

populations in tsunami-prone land (for example, Manzanita, 

Yachats, Bandon, and Port Orford) may need special evacuation and relief procedures for this demographic group.

Gender differences also influence an individual’s sensitivity to a stressor (Enarson and Morrow, 1998; Bateman 

and Edwards, 2002). Preliminary work by Oxfam (2005) in 

the wake of the 2004 Sumatra-Andaman tsunami indicates 

that women had a disproportionately higher mortality rate. 

Research of gender differences to natural hazards indicates 

that women tend to have higher risk perceptions, demonstrate higher preparedness planning, and are more likely to 

respond to warnings than men but also are more likely to be 

single parents or primary care givers, have special medical 

needs, have lower incomes, and less autonomy than males. 

Research also indicates that there are more documented 

reports after natural disasters of women with post-traumatic 

stress (Ollenberger and Tobin, 1998) and of abuse against 

women (Enarson, 1999). The heightened vulnerability of 

women to extreme events is believed to be a reflection of 

broader cultural, political, and economic inequalities within 

a society and not due to physical differences of the sexes 

(Morrow, 1999; Bateman and Edwards, 2002). Results indicate that 51 percent of residents in the tsunami-inundation 

zone are women, identical to the study area percentage. For 

the individual jurisdictions, the percentage of residents in 

the tsunami-inundation zone that are female ranges from 

42 percent (unincorporated Douglas County) to 58 percent 

(City of Bandon). Results also indicate that 5 percent of 

households in the tsunami-inundation zone are single-mother 

households, slightly lower than the 6 percent for the study 

area. Single-mother households may have unique evacuation and recovery issues, as they are more likely to have 

limited mobility and fewer financial resources (Laska and 

Morrow, 2007). The percentage of single-mother households 

in tsunami-prone land ranges from zero percent in Wheeler 

to 12 percent in Waldport and Nehalem (fig. 11B), although 

the high percentage in Nehalem reflects a small number of 

households in its hazard zone.

Tenancy is another factor that influences individual 

sensitivity to stressors, as studies have shown that renters 

are less likely than homeowners to prepare for catastrophic 

events (Morrow, 1999; Burby and others, 2003). Theories 

on why this is the case include (1) higher turnover rates for 

renters that may limit their exposure to hazard information, (2) preparedness campaigns may pay less attention to 

renters, (3) renters typically have lower incomes and fewer 

resources to prepare, and (4) renters may lack the motivation 

to invest in mitigation measures for rented property (Burby 

and others, 2003). After a disaster, renters also have little 

control over the speed with which rental housing is repaired 

or replaced (Laska and Morrow, 2007). Results indicate that 

37 percent of households in the tsunami-inundation zone are 

renter-occupied (table 1), and values within the jurisdictions 

range from 10 percent (City of Wheeler) to 56 percent (City 

of North Bend) (fig. 11C). 

Demographic characteristics germane to societal vulnerability that are available at census block-group and tract levels (Cutter and others, 2003) are summarized for each county 

in the study area (fig. 12). Following the disaster pressure 

and release model (Wisner and others, 2004), vulnerability 

is the characteristics of a group that influences their ability 

to anticipate and cope with the impacts of a natural hazard; 

attributes summarized in figure 12 are pre-event characteristics that could attenuate or amplify the societal impact of a 

tsunami, or any natural hazard for that matter. Results indicate that the seven counties are below Oregon and National 

averages in terms of households earning more than $75,000, 

slightly above Oregon and National averages in the percent-
Percentage of Residents in 

Tsunami-Inundation Zone

That Are Over 65 Years in Age

Percentage of Households in 

Tsunami-Inundation Zone

That Are Female Headed, 

With Children, No Spouse Present

0% 50%

3rd 

Quartile 

(29%)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

3rd 

Quartile 

(7%)

25% 0% 14%

Percentage of Households in 

Tsunami-Inundation Zone

That Are Renter Occupied

0% 30% 60%

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

3rd 

Quartile 

(43%)

A B C

Results 15

Figure 11. Percentage of residential population in the tsunami-inundation zone that is (A) residents over 65 years in age, 

(B) female-headed households, with children, no spouse present, and (C) renter-occupied households.

age of population for whom poverty status is determined 

and in the percentage of civilian labor force unemployed, 

and are greatly above Oregon and National averages in the 

percentage of housing units that are mobile homes and in the 

percentage of households receiving Social Security benefits. 

The percentage of population 25 years or older with no high 

school diploma in the 7 counties fall between the Oregon 

(14.9 percent) and National (19.6 percent) averages. Overall, 

these socioeconomic indicators suggest that post-tsunami 

recovery could be slow on the Oregon coast, considering 

the relatively low income levels, the high dependence on 

Federal benefits, and the high number of residents living in 

mobile homes. 

Employees

The tsunami-inundation zone contains 14,857 employees 

at 1,829 businesses, representing 7 percent of the businesses 

and 6 percent of the employees in the seven counties (table 2). 

Third-quartile values for the amount and percentage of employees working in the tsunami-inundation zone of the 26 cities and 

7 counties are 455 employees and 31 percent of a jurisdiction’s 

workforce. Similar to residential populations, the amount (fig. 

13A) and percentage (fig. 13B) of employee populations in the 

tsunami-inundation zone vary considerably in the study area, 

with higher amounts and percentages in the more-northern 

cities. Some cities, such as Seaside and Warrenton, have high 
Cl

Cl Cl

Cu

Cu

Cu

Cu

Cu

0%

10%

20%

30%

40%

50%

Percentage Of

Households

Earning 

More 

Than 

$75,000

Percentage Of

Civilian 

Labor

Force 

Unemployed

Percentage Of

Housing

Units

That Are

Mobile 

Homes

Percentage Of

Individuals 

For Whom 

Poverty 

Status 

Is Established

Percentage Of

Individuals

25 Years or More

With No 

High School 

Diploma

Percentage Of

Households

Receiving

Social 

Security

Benefits

T

Cl

Co

D

La

Li

State of Oregon Average

National Average 

La

La

La La

Co

Co

Co

Co

Co

Li

Li

Li

Li

D

D

D

T

T

T

T T

Li D Cl La

D Cu Li Cl

Cu Curry County

T Tillamook County

Cl Clatsop County

Co Coos County

D Douglas County

La Lane County

Li Lincoln County

16 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

numbers of employees in the tsunami-inundation zone (3,446 

and 1,764, respectively) that represent high percentages of their 

total workforce (89 percent and 64 percent, respectively). Other 

cities have much lower numbers of employees in the tsunamiinundation zone, including Gearhart (365) and Rockaway Beach 

(355), but these amounts represent the majority of the local 

workforce (73 percent and 68 percent, respectively). Unlike the 

residential data, there are not large numbers of employees in the 

tsunami-prone portions of unincorporated county land.

Dependents

Several dependent-population facilities are in the tsunamiinundation zone (table 3), including 14 schools, 10 adult-residential-care centers, 9 outpatient-care facilities and 7 child-daycare centers, and many of these facilities are in northern cities 

(fig. 14). Additional evacuation planning may be required in 

communities with high dependent populations (for example, the 

City of Seaside) due to the limited mobility of certain groups, 

such as those in schools and nursing homes. Traditional relief 

efforts may need to be augmented if a community has a significant adult residential care population due to potential health 

complications after a disaster. In addition to unique evacuation 

and relief issues, many dependent-population facilities represent critical social services that, if lost, could slow community 

recovery following an extreme event. For example, the loss of 

child-day-care facilities or schools could keep some parents 

from returning to their jobs until suitable arrangements can be 

made for their children and, in smaller communities, this delay 

Figure 12. Blockgroup- and tract-level demographic characteristics for residential populations in Oregon 

coastal counties, based on the 2000 Census.

Table 2. Amount and percentage of economic assets in the Oregon 

tsunami-inundation zone.

Table 3. Amount and percentage of dependent-population facilities 

in the Oregon tsunami-inundation zone.

Economic Asset Inundation

Zone

Study Area

Total Percentage

Businesses 1,829 26,775 7%

Employees 14,857 251,227 6%

Sales volume

(in U.S. dollars) $1,881,774,000 $38,000,598,000 5%

Total tax-parcel 

value (in U.S. 

dollars) $8,158,045,904 $68,343,196,747 12%

Facility Inundation 

Zone

Study Area 

Total Percentage

Adult-residential-care 

facilities 10 213 5%

Child-day-care facilities 7 139 5%

Correctional facilities 1 16 6%

Hospitals 0 18 0%

Outpatient-care facilities 9 420 2%

Psychiatric and substance 

abuse hospitals 2 22 9%

Schools 14 412 3%
Percentage of Employees in

Tsunami-Inundation Zone

0% 50% 100%

3rd Quartile 

(31%)

0 4,000

Number of Employees in

Tsunami-Inundation Zone

3rd Quartile 

(455)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

2,000

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

A B

Results 17

Figure 13. Number (A) and percentage (B) of employees in the Oregon tsunami-inundation zone.
Number of Dependent-Population 

Facilities in Tsunami-Inundation Zone

0

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

2 4 6 8 10 12 14

Adult Residential Care

Correctional Facilities

Child Day Care

Outpatient Care

Psychiatric Hospitals

Schools

18 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

could take weeks. Therefore, although a business may escape 

debilitating physical damage from the original earthquake or 

tsunami, it may suffer economic damages as a result of staffing 

challenges associated with the loss of community services.

Public Venues

There are several public venues in the tsunami-inundation 

zone that likely attract high numbers of local populations and 

tourists, including 34 religious facilities and 8 libraries (table 4). 

Similar to dependent-population facilities, the highest numbers 

of public venues in the tsunami-inundation zone are in the City 

of Seaside and other northern cities (fig. 15). The high numbers 

of public venues in the tsunami-inundation zone present both 

challenges and opportunities for the emergency-management 

community. An obvious challenge is the large number of 

individuals that would be in the tsunami-inundation zone if an 

event were to occur during a high-occupancy time (for example, 

during a religious service). The presence of public venues in the 

tsunami-inundation zone, however, also presents an outreach 

opportunity for county and State emergency managers to work 

with owners and employees of these public venues to further 

educate local populations and to reach tourist populations. 

The tsunami-inundation zone contains 171 overnighttourist facilities (including bed and breakfasts, cabins, camps, 

campgrounds, health resorts, hostels, hotels, inns, resorts, and 

tourist accommodations), representing 25 percent of all such 

facilities in the seven coastal counties and 43 percent of these 

facilities are in the City of Seaside (fig. 16). Five overnighttourist facilities is the regional third-quartile value, indicating 

that most cities do not have many of these businesses in the 

tsunami-inundation zone. Most overnight-tourist facilities in 

the tsunami-inundation zone are clustered in only a few cities, 

such as Seaside (43), Lincoln City (28), Cannon Beach (24), 

Table 4. Amount and percentage of public venues in the Oregon 

tsunami-inundation zone.

Figure 14. Number of dependent-population facilities in the 

Oregon tsunami-inundation zone.

Public Venue Inundation 

Zone

Study 

Area Percentage

Aquariums 2 3 67%

Botanical gardens 0 1 0%

Casinos 2 5 40%

Colleges and universities 3 29 10%

Libraries 8 66 12%

Museums 3 33 9%

Parks 1 43 2%

Religious organizations 34 817 4%

Shopping centers and malls 1 9 11%

Sporting facilities 0 4 0%

Theaters 6 46 13%

Zoos 0 0 0%
Number of Public Venues

in Tsunami-Inundation Zone

0 6 12 18

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

Aquariums

Casinos

Colleges and

Universities

Libraries

Museums

Religious

Organizations

Shopping Center

Theaters

Number of Overnight-Tourist Facilities 

in Tsunami-Inundation Zone

0 50

3rd Quartile (5)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

Results 19

Figure 15. Number of public venues in the Oregon tsunamiinundation zone.

Figure 16. Number of overnight-tourist facilities in 

the Oregon tsunami-inundation zone.
20 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

and Rockaway Beach (15). Although tourist-related lodging in tsunami-prone areas provides some insight on tourist 

exposure, the number of tourists at risk is likely much greater, 

due to the number of unaccountable individuals staying with 

friends and family and those who go to the coast during the 

day but stay at hotels outside of the tsunami-inundation zone.

The sum of the annual-average number of visitors 

(1998–2003) to 66 Oregon State Parks in the tsunamiinundation zone is 19,605,770 people per year. Assuming 

an equal distribution of visitors on every day of the year, 

this corresponds to 53,714 day-use visitors to Oregon State 

Parks on average every day. In reality, this number is low 

because attendance is not equally distributed throughout the 

year; there will be seasonal peaks in park attendance (for 

example, summer months and holidays). The highest annual 

average number of day-use visitors for the 66 parks are for D 

River State Recreation Site (1,175,581 visitors per year and 

near Lincoln City) and Yaquina Bay State Recreation site 

(1,135,584 visitors per year and near Newport) (fig. 17A). 

After adding the number of day-use visitors at parks based 

on nearby incorporated cities, it is clear that the majority 

of visitors are going to parks in the central Oregon coast 

(fig. 17B); for example, 44 percent of the Oregon State Park 

visitors are going to parks in Lincoln County. The highest percentages are for parks near the cities of Newport (19 

percent) and Lincoln City (11 percent). Coastal parks in 

southern Oregon, specifically those in Curry County, also see 

a significant number of park visitors; an interesting finding because coastal cities in this area have otherwise low 

amounts of assets in the tsunami-inundation zone. 

Economic Assets

The tsunami-inundation zone contains parcel values collectively assessed at approximately $8.2 billion, representing 

12 percent of the total tax-parcel value in the seven counties 

(table 3). The amount (fig. 18A) and percentage (fig. 18B) of 

total tax parcel value in the tsunami-inundation zone varies 

significantly across the study area. The third-quartile value for 

total tax-parcel value in the tsunami-inundation zone among 

the 26 cities and 7 unincorporated county lands is approximately $361 million. The highest total exposed tax parcel 

values in the incorporated cities are in Seaside ($843 million) 

and Cannon Beach ($605 million), representing 90 percent 

and 69 percent, respectively, of the total tax base in these 

cities. The highest total exposed parcels value for the region 

is the rural portion of Tillamook County (approximately $1.2 

billion), reflecting the unincorporated towns of Cape Meares, 

Cloverdale, Oceanside, Neskowin, Netarts, and Pacific City. 

The unincorporated portions of the other counties, specifically 

Clatsop and Lincoln, also have high total parcel values in the 

tsunami-inundation zone. As is the case with residential and 

employee distributions, some cities (for example, Gearhart, 

Toledo, and Yachats) have relatively low amounts of tax parcel 

value in the tsunami-inundation zones but the exposed parcels 

represent a high percentage of a city’s total tax base. Building damages due to CSZ-related tsunamis, as well as from the 

preceding earthquake, could significantly lower the content 

value of individual properties, thereby lowering the tax base of 

a community after a tsunami disaster, and reducing the funds 

available for long-term recovery.

Results indicate that there are 1,829 businesses with 

14,857 employees that generate over $1.9 billion in sales 

volume in the Oregon tsunami-inundation zone, representing 

seven percent of all businesses, six percent of employees, and 

five percent of generated sales volume in the seven coastal 

counties (table 2). High percentages of employees in tsunamiinundation zone represent economic fragility for a community, 

as unemployment could increase dramatically overnight if a 

tsunami injures or kills employees or if it damages or destroys 

businesses. Even if a business escapes damage or physical 

disruption due to an extreme event, it may still experience 

significant customer and revenue loss if the neighborhood and 

other businesses around it are damaged, leading customers 

to shop elsewhere. Neighborhood effects have been found to 

be especially important for retailers that rely on foot traffic 

(Chang and Falit-Baiamonte, 2002), a potentially significant 

issue for tourist-related retail and food services within Oregon 

coastal communities. Therefore, knowing where there are 

high numbers and percentages of employees can help identify 

potential economic recovery issues. 

Results indicate that cities on the northern Oregon 

coast have the highest percentages of their employees in the 

tsunami-inundation zone (fig. 13B), including Seaside (89 

percent), Cannon Beach (79 percent), Gearhart (73 percent), 

and Rockaway Beach (68 percent). Some cities have high 

numbers of employees in tsunami-inundation zones but these 

numbers represent a small proportion of the local economy; 

for example, there are 1,185 employees in the tsunami-inundation zone in the City of Newport, but these employees only 

represent 14 percent of the city’s workforce. Smaller cities, 

such as Gearhart and Rockaway Beach have much smaller 

numbers of employees in their tsunami-inundation zones (365 

and 355 employees, respectively), but face relatively larger 

economic threats from a tsunami than Newport because of 

the larger employee percentages (73 percent and 68 percent, 

respectively).

Societal vulnerability is also influenced by the types of 

businesses in the tsunami-inundation zone. If the dominant 

business sectors in the tsunami-inundation zone are accommodations and food services, then a primary concern for local 

responders is the high number of tourists likely in danger. If 

the businesses are primarily manufacturing facilities, response 

issues may center instead on employees and the potential for 

hazardous-material spills. The highest numbers of employees 

in the seven Oregon coastal counties (fig. 19) are in retail trade 

(16 percent), accommodation and food services (12 percent), 

health care and social assistance (11 percent), and manufacturing (11 percent). Employee distributions for businesses in 

the tsunami-inundation zone are similar to the entire study 

area, except for an increase in the accommodation and food
Figure 17. Annual average number of visitors to coastal Oregon State Parks (1998-2003) illustrated (A) by the amount 

per State park and (B) as a percentage related to nearby incorporated cities.

Historical Area = HA; State Natural Area = SNA; State Park = SP; State Recreation Area = SRA; State Recreation Site = SRS;

State Scenic Viewpoint = SSV.

0 10% 20%

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Florence

Reedsport

Lakeside

North Bend

Coos Bay

Bandon

Port Orford

Gold Beach

Brookings

Percentage of Annual Average Number 

of Visitors at Nearby Oregon State Parks

3rd Quartile 

(6%)

1,200,000

Annual Average Number of Visitors to 

Oregon State Parks (1998-2003)

0

Fort Stevens SP

Ft. Stevens HA

Del Rey Beach SRC

Ecola SP

Tolovana Beach SRS

Arcadia Beach SRS

Hug Point SRS

Oswald West SP

Nehalem Bay SP

Manhattan Beach SRS

Cape Meares SSV

Oceanside Beach SRS

Cape Lookout SP

Bob Straub SP

Neskowin Beach SRS

Roads End SRS

Devil's Lake SP

D River SRS

Gleneden Beach SRS

Fogarty Creek SRA

Boiler Bay SSV

Rocky Creek SSV

Otter Crest SSV

Devil's Punchbowl SNS

Beverly Beach SP

Agate Beach SRS

Yaquina Bay SRS

South Beach SP

Lost Creek SRS

Ona Beach SP

Seal Rock SRS

Driftwood Beach SRS

W.B. Nelson SRS

Governor Patterson SRS

Beachside SP

Smelt Sands SRS

Yachats SRA

Yachats Ocean Road SNS

Neptune SSV

Stonefield Beach SRS

Muriel O. Ponsler Mem. SSV

Carl Washburne Mem. SP

Heceta Head Lighthouse SSV

Jessie M Honeyman SP

Umpqua Lighthouse SP

William M. Tugman SP

Bullards Beach SP

Face Rock SSV

Bandon SNA

Cape Blanco SP

Paradise Point SRS

Port Orford Heads SP

Humbug Mountain SP

Geisel Monument SHS

Otter Point SRS

Cape Sebastian SSC

Pistol River SSV

S.H. Boardman SSC

Harris Beach SP

Brookings Day-use

Winchuck SRS

Sunset Bay SP

Shore Acres SP

Cape Arago SP

Seven Devils SRS

600,000

Warrenton

Gearhart

Cannon Beach

Manzanita

Rockaway Beach

Tillamook

Lincoln City

Depoe Bay

Newport

Waldport

Yachats

Florence

Reedsport

Coos Bay

Bandon

Port Orford

Gold Beach

Brookings

A B

Results 21
Percentage of Parcel Value in

Tsunami-Inundation Zone

0% 50% 100%

3rd 

Quartile 

(37%)

0 $1.2 Billion

Amount of Parcel Value in

Tsunami-Inundation Zone

A B

3rd 

Quartile 

($0.36 Billion)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

$0.6

 

22 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

Figure 18. Amount (A) and percentage (B) of total tax-parcel value in the Oregon tsunami-inundation zone.
Agriculture, Forestry, Fishing and Hunting

Mining

Utilities

Construction

Manufacturing

Wholesale Trade

Retail Trade

Transportation and Warehousing

Information

Finance and Insurance

Real Estate and Rental and Leasing

Professional, Scientific, and Technical Services

Management of Companies and Enterprises

Administrative and Support and Waste Management

Educational Services

Health Care and Social Assistance

Arts, Entertainment, and Recreation

Accommodation and Food Services

Other Services (except Public Admin.)

Public Administration

Unclassified

0% 10% 20%

Percentage of Employees, 

by Business Sector

Tsunami-Inundation Zone

Study Area

30%

Results 23

Figure 19. Percentage of employees, by business sector, in the Oregon tsunami-inundation zone.
24 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

services businesses (from 12 percent for all businesses to 27 

percent for those in the tsunami zone), an increase in the arts, 

entertainment and recreation businesses (from 3 percent to 10 

percent), and a decrease in health care and social assistance 

businesses (from 11 percent down to 6 percent). 

The percentage of employees in the accommodation and 

food services sector for businesses in the tsunami-inundation 

zone (27 percent) is over three times the national average of 

8.3 percent (2005 value) for the same industry sector (Bureau 

of Labor Statistics, 2007b), reflecting the dominance of the 

tourism sector along the Oregon coast (fig. 19). This dominance is also reflected in the high percentage of employees in 

the arts and entertainment sector for businesses in the tsunamiinundation zone (3 percent), a percentage twice the national 

average of 1.4 percent (Bureau of Labor Statistics, 2007b). 

The fourth highest employee percentages in the tsunami-prone 

areas are in the manufacturing sector (10 percent), demonstrating that many Oregon port and harbor communities are not 

simply tourist destinations but are also working ports with significant seafood- and timber-processing businesses. The high 

percentage of retail trade, accommodations and food services, 

and arts and entertainment sectors indicate that the tsunamiinundation zone likely contains significant tourist populations. 

The high percentage of manufacturing facilities indicate that 

the tsunami-inundation zone also likely contains hazardous material and heavy machinery (both commonly found 

in industrial zones) that could be dispersed and transported 

throughout an estuary during a tsunami. In addition to providing emergency managers with estimate of potential impacts 

from a tsunami, this information also helps economic planners 

determine the type of business continuity planning needed 

before a disaster and recovery assistance after a disaster. A 

mixed economy with strong retail, accommodations and food 

services, and manufacturing sectors indicate that economic 

recovery along the Oregon coast will be multifaceted, with 

each sector having different needs.

Critical and Essential Facilities

Several critical and essential facilities are in the Oregon 

tsunami-inundation zone (table 5). The low number of exposed 

hospitals (0) and outpatient-care centers (1), but high number 

of exposed physician and dentist offices (27), indicates that 

hospitals may be able to handle casualties and injuries during 

the immediate response phase of a disaster but some communities may experience difficulties in maintaining medical 

services during the longer-term recovery phase if they lose a 

significant number of doctor offices. Long-term community 

recovery also may also be hampered by the potential loss of 

the numerous essential facilities in the tsunami-inundation 

zone, including government offices (21), banks and credit 

unions (16), grocery stores (15) and U.S. Post Offices (12). 

Information on types of facilities within each city and whether 

they are in the tsunami-inundation zone is available in the 

accompanying database (appendix B).

In most cases, the percentages are low for most categories when comparing critical and essential facilities in the 

tsunami-inundation zone to the entire study area (table 5). 

Therefore, local populations could be inconvenienced by the 

loss of specific facilities in their communities but may be 

able to find the services elsewhere. A next step for analysis is 

to determine the redundancy of facility functions in a city or 

across the region. For example, results indicate that several 

police stations (8) are in the Oregon tsunami-inundation zone. 

If neighboring communities both lost their police stations, then 

the ability to maintain order for that area is compromised even 

more. However, if one town loses a station and the other does 

not, resources could possibly be shared between communities. Facility access is another area for further research. For 

example, results indicate that the hospital in the City of Seaside is not in the tsunami-inundation zone. However, assuming 

the hospital in Seaside escapes damage from the CSZ-related 

earthquake and associated tsunamis, neighboring communiTable 5. Amount and percentage of critical and essential facilities 

in the Oregon tsunami-inundation zone.

TsunamiInundation 

Zone

Study Area 

Total Percentage

Critical facilities

Civil-defense facilities 0 3 0%

Fire stations 5 58 9%

National-security facilities 4 31 13%

Police stations 8 65 12%

Ambulance services 0 13 0%

Hospitals 0 18 6%

Outpatient-care centers 1 53 2%

Electrical facilities 2 14 14%

Public-works facilities 2 43 5%

Gas facilities 0 11 0%

Radio and television facilities 3 53 6%

Waste-water facilities 1 15 7%

Water and sewer facilities 1 41 2%

Essential facilities

Banks and credit unions 16 270 6%

Courts and legal offices 1 40 3%

Physician/Dentist Offices 27 648 4%

Gas stations 7 115 6%

Government offices 21 406 5%

Groceries 15 255 6%

International-affairs offices 0 0 0%

U.S. Post Offices 12 110 11%
Exposure Sensitivity

Sum of Normalized Indices

Astoria

Warrenton

Gearhart

Seaside

Cannon Beach

Clatsop Co. (remainder)

Manzanita

Nehalem

Wheeler

Rockaway Beach

Garibaldi

Bay City

Tillamook

Tillamook Co. (remainder)

Lincoln City

Depoe Bay

Newport

Toledo

Waldport

Yachats

Lincoln Co. (remainder)

Florence

Lane Co. (remainder)

Douglas Co. (remainder)

Lakeside

North Bend

Coos Bay

Bandon

Coos Co. (remainder)

Port Orford

Gold Beach

Brookings

Curry Co. (remainder)

12345 0 1 2 3 4 5

Figure 20. Comparison of normalized exposure and sensitivity indices 

for incorporated cities in the Oregon tsunami-inundation zone.

0

6

12

18

0.0 - 0.5

0.5 - 1.0

1.5 - 2.0

2.0 - 2.5

2.0 - 2.5

2.5 - 3.0

3.0 - 3.5

3.5 - 4.0

4.0 - 4.5

4.5 - 5.0

Exposure Values

Sensitivity Values

Number of Communities

Sum of Normalized Community Assets

Results 25

facilities on impaired roads and the level of dependency on 

critical facilities between communities are topics that require 

further analysis. 

Composite Indices of Exposure and Sensitivity

 Composite indices of exposure (based on amounts) and 

sensitivity (based on percentages) for each of the 26 cities and 

the 7 rural county areas are the sums of normalized data in 5 

categories–developed land, residents, employees, public venues, 

and total parcel value. Table 6 summarizes the composite 

exposure and sensitivity values (each with a range from 0 to 5) 

for the 26 cities and 7 unincorporated county lands where higher 

values indicate higher relative exposure or sensitivity. Figure 20 

provides the same information in graphical form with the exposure scale vertically mirrored to facilitate visually comparisons 

of exposure and sensitivity values for individual cities. The City 

of Seaside has the highest composite exposure value (4.7) and 

composite sensitivity value (4.9), indicating that this city consistently has the highest amount and percentage of assets in the 

tsunami-inundation zone (fig. 20). Results indicate that some 

cities (for example, Lincoln City) have higher relative exposure 

than sensitivity values, while others (for example, Rockaway 

Beach) have higher relative sensitivity than exposure (fig. 20). 

A frequency histogram depicting the distribution of composite exposure and sensitivity values indicates that the City of 

Seaside is somewhat of an outlier of city vulnerability (fig. 21). 

The x-axis shows the composite values in 0.5 increments and 

the y-axis notes the number of jurisdictions. Most cities and 

unincorporated county lands have composite exposure values 

less than 1.0, indicating that they have considerably fewer assets 

in tsunami-prone areas than the City of Seaside. Although 

many communities also have composite sensitivity values less 

ties that rely on this hospital for medical services may have 

difficulty accessing the functioning facility on blocked or 

impaired roads, due to earthquake-related ground deformation 

and landslide debris or tsunami-related debris and deposition. 

For example, the City of Seaside was temporarily isolated 

from neighboring communities due to storm-related damage 

and flooding of access roads after a winter storm struck the 

region on 12/2/07 (Trappen, 2007). Therefore, although the 

percentage of critical and essential facilities in the Oregon 

tsunami-inundation zone is low, the ability to access these 

Figure 21. Frequency histogram of the sum of normalized exposure 

and sensitivity indices for incorporated cities in the Oregon 

tsunami-inundation zone.
26 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

than 1.0, four cities have sensitivity values between 3.0 and 5.0 

(Gearhart, Rockaway Beach, Cannon Beach, and Warrenton), 

indicating relatively high sensitivity to tsunamis similar to that 

of Seaside.

To provide some insight on which cities have the highest 

combined exposure and sensitivity to tsunamis, composite exposure and sensitivity values are normalized to maximum values 

found in each category and then added to create a combined 

exposure and sensitivity value (fig. 22). The City of Seaside has 

the highest combined exposure and sensitivity value of 2.0, indicating that it is the highest in both categories. The next highest 

combined values are for the cities of Gearhart, Warrenton, Cannon Beach, and Rockaway Beach, where high relative vulnerability is primarily due to high sensitivity. The unincorporated 

portion of Tillamook County has the sixth highest combined 

value.

Exposure and sensitivity comparisons are only first 

approximations of societal vulnerability because they do 

not include variations in resilience, the third component that 

influences vulnerability (Turner and others, 2003). The ability 

of a community to withstand, absorb, adapt to, and recover 

from losses defines its resilience, and—with other conditions 

Range Composite Exposure Values Composite Sensitivity Values

4.0 to 5.0 - Seaside - Seaside

- Gearhart

3.0 to 3.9

- Rockaway Beach

- Cannon Beach

- Warrenton

2.0 to 2.9

-Unincorporated Tillamook County (including Cape 

Meares, Cloverdale, Oceanside, Neskowin, Netarts, 

and Pacific City)

- Warrenton

- Waldport

1.0 to 1.9

- Lincoln City

- Cannon Beach

- Unincorporated Lincoln County (including Lincoln 

Beach and Rose Lodge)

- Newport

- Unincorporated Clatsop County

- Rockaway Beach

- Yachats

- Unincorporated Tillamook County (including Cape Meares, 

Cloverdale, Oceanside, Neskowin, Netarts, and Pacific City)

- Lincoln City

- Toledo

- Manzanita

0 to 0.9

- Unincorporated Curry County (including Harbor)

- Unincorporated Coos County (including Barview 

and Bunker Hill)

- Gearhart

- North Bend

- Waldport

- Florence

- Astoria

- Bandon

- Toledo

- Unincorporated Douglas County (including 

Winchester Bay)

- Yachats

- Gold Beach

- Coos Bay

- Brookings

- Manzanita

- Unincorporated Lane County

- Tillamook

- Garibaldi

- Depoe Bay

- Bay City

- Port Orford

- Wheeler

- Nehalem

- Lakeside

- Unincorporated Lincoln County (including Lincoln Beach and 

Rose Lodge)

- Unincorporated Curry County (including Harbor) 

- Unincorporated Coos County (including Barview 

and Bunker Hill)

- North Bend

- Florence

- Unincorporated Clatsop County

- Astoria

- Bandon

- Unincorporated Douglas County (including Winchester Bay)

- Gold Beach

- Coos Bay

- Brookings

- Unincorporated Lane County

- Tillamook

- Garibaldi

- Depoe Bay

- Bay City

- Port Orford

- Wheeler

- Nehalem

- Lakeside

Table 6. Composite exposure and sensitivity values for cities in the Oregon tsunami-inundation zone.
Sum of Normalized Composite 

Exposure and Sensitivity Values

0.0 1.0 2.0

Seaside

Gearhart

Warrenton

Cannon Beach

Rockaway Beach

Tillamook Co. (remainder)

Lincoln City

Waldport

Lincoln Co. (remainder)

Yachats

Newport

Curry Co. (remainder)

Clatsop Co. (remainder)

North Bend

Toledo

Manzanita

Bandon

Florence

Coos Co. (remainder)

Gold Beach

Astoria

Garibaldi

Brookings

Coos Bay

Douglas Co. (remainder)

Depoe Bay

Wheeler

Port Orford

Nehalem

Bay City

Tillamook

Lane Co. (remainder)

Lakeside Sensitivity

Exposure

Results 27

Figure 22. Sum of normalized exposure and sensitivity indices for 

incorporated cities in the Oregon tsunami-inundation zone.

remaining the same—greater resilience lowers a community’s 

vulnerability to extreme events. For example, if two communities have identical community assets in tsunami-prone land, 

but one has a tsunami education program, a well-rehearsed 

evacuation plan, redundant critical infrastructure, and a 

holistic post-disaster recovery plan and has met the criteria 

for certification as a TsunamiReady community (National 

Weather Service, 2007), then that community is assumed to 

have greater resilience, resulting in more-efficient response 

operations and shorter recovery times after the extreme event. 

Despite similar asset distributions, the same extreme natural 

event may create a short-term crisis in the more resilient community and a longer-term disaster in the less-resilient community. Follow-up studies to document variations in potential 

community resilience would complement this report, providing the State of Oregon with a more complete understanding 

of societal vulnerability to tsunamis.

Statistical Relationship to Land Cover

Linear regression analyses were performed to test the 

hypothesis that distributions of city assets correlate to the 

distribution of city land (regardless of land-cover class) and 

were done for values of exposure (the amounts of land compared to the amounts of various assets in tsunami-inundation 

zones) and of sensitivity (the percentages of land compared 

to the percentage of various assets in tsunami-prone areas). 

Based on criteria of p < 0.05, results indicate that some, but 

not all relationships are significant (table 7). For exposure 

values, the relationships between the amount of tsunamiprone land in a city and the amounts of employees (p = 0.52) 

and tourist facilities (p = 0.69) in these areas are not statistically significant. Relationships are significant between the 

amount of land and the amount of developed land (p = 0.01), 

residents (p = 0.03), and total parcel value (p < 0.01); however, low explained variance (r2

) values for these assets (0.19, 

0.15, and 0.27, respectively) suggest that the relationships, 

although statistically significant, are not strong. For sensitivity values, relationships are statistically significant between 

the percentage of city land in the tsunami-inundation zone and 

the percentage of city assets in the zone (all p < 0.01). Unlike 

the significant exposure relationships, r2

 values for sensitivity 

comparisons are strong, ranging from 0.64 for employees to as 

much as 0.87 for residents. 

Two graphs are provided to help visualize the differences between the nonsignificant and significant relationships reported here. Figure 23A is a scatter-plot comparing 

the amount of city land in tsunami-inundation zones with the 

amount of employees in tsunami-inundation zones (both normalized to maximum values for comparison purposes) for the 

33 geographic units. No significant relationship exists between 

the two datasets (p = 0.52, r2 = 0.01) and the graph shows little 

discernible trend in the points. Figure 23B shows the percentage of city land compared to the percentage of employees, in 

which a statistically significant relationship is present and the
0.0

0.2

0.4

0.6

0.8

1.0

A B

0.0 0.2 0.4 0.6 0.8 1.0

Amount of Land in Tsunami-Inundation Zone (normalized)

Number of Employees in Tsunami-Inundation Zone (normalized)

0%

20%

40%

60%

80%

100%

0% 20% 40% 60% 80% 100%

Percentage of Land in Tsunami-Inundation Zone

Percentage of Employees in Tsunami-Inundation Zone

R = 0.01

p = 0.52

2

R = 0.64

p << 0.01

2

Community

Regression line

Community

Regression line

28 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

r2 value of 0.64 is reflected in a distinct clustering of points 

around the regression line.

Results indicate that the amount of city assets in tsunamiinundation zones does not have a strong correlation with the 

amount of city land in these areas. In other words, two cities 

with the same amount of tsunami-prone land have made different land-use decisions on the amount of development in these 

threatened areas. Strong relationships between the percentages 

of city assets in the tsunami-inundation zone and the percentage of city land in this zone indicate that although there are few 

common patterns of asset distribution in the tsunami-inundation 

zone among cities, there is consistency within individual cities. 

Consequently, knowing the amount of tsunami-prone city land 

does not indicate the level of city exposure to tsunamis. However, knowing the percentage of city land in tsunami-prone areas 

can approximate how sensitive a city may be to a tsunami.

Summary

This report describes the landscape in the ORS 455 

tsunami-inundation zone and compares city exposure and 

sensitivity to tsunamis. Based on a geospatial analysis of the 

distribution of developed land, populations, economic assets, 

and critical facilities relative to the Oregon tsunami-inundation 

zone, the following conclusions can be made: 

(1) The majority of tsunami-prone land (95 percent) is 

classified as undeveloped, although these areas likely attract 

recreationists and provide ecosystem services to the region;

(2) A significant portion of the 22,201 residents in the 

tsunami-inundation zone is 65 years in age or older (45 percent in one city) or a renter (37 percent of the all households in 

the tsunami zone), indicating a need for unique preparedness, 

response, and recovery procedures in some cities;

Figure 23. Scatter-plots comparing the amounts (A) and percentages (B) of land and of employees for incorporated cities 

in the Oregon tsunami-inundation zone. 

Table 7. Statistical results comparing land data and societal assets in the Oregon tsunamiinundation zone.

Regression significance 

between landcover with:

Exposure Values Sensitivity Values

R R2 F* P R R2 F* P

 Developed Land 0.44 0.19 7.26* 0.01 0.92 0.85 174.35* < 0.01

 Residents 0.38 0.15 5.32* 0.03 0.93 0.87 212.19* < 0.01

 Employees 0.12 0.01 0.43 0.52 0.80 0.64 55.19* < 0.01

 Tourist facilities 0.07 0.01 0.17 0.69 0.87 0.76 99.03* < 0.01

 Total Parcels Value 0.52 0.27 11.27* 0.00 0.88 0.77 101.66* < 0.01

*

A regression relationship is considered significant at p < 0.05 if F > 4.17, as F0.05(1),1,31 = 4.17.
Acknowledgments 29

(3) Thirty-six percent of the residents in the tsunamiinundation zone are in the unincorporated portions of the 

seven counties, indicating the importance of awareness 

programs and evacuation planning in rural communities;

(4) Nonresidential populations in the tsunami-inundation zone are significant, including 14,857 employees, 

53,714 day-use visitors on average per day to Oregon State 

Park, and a high number of dependent-population facilities 

(for example, child- and adult-day care facilities), overnighttourist accommodations, and public venues (for example, 

religious organizations);

(5) The 1,829 businesses in the tsunami-inundation 

zone are primarily retail trade, accommodation and food 

services, health services, or manufacturing, indicating variations in the amount of on-site customers and tourists that 

businesses must deal with in the event of a disaster and variations in the type of business continuity planning needed to 

facilitate post-disaster recovery;

(6) Economic recovery needs will vary across the 

region, with some cities potentially experiencing no direct 

business impact (Port Orford) and others possibly losing 89 

percent of their workforce (Seaside);

(7) City exposure and sensitivity to tsunamis vary 

across the region with some cities having high amounts but 

low percentages of assets in the tsunami-inundation zone (for 

example, employees in Lincoln City and Newport) and others having low amounts that represent high percentages (for 

example, residents in Cannon Beach and Rockaway Beach);

(8) The City of Seaside has the highest amounts and 

percentages of developed land, residents, employees, dependent-population facilities, public venues, overnight facilities, 

and total parcel values of the 26 cities and seven counties 

with land in the tsunami-prone land; and 

(9) Knowing the amount of tsunami-prone city land 

does not indicate the level of city exposure, but knowing the 

percentage of city land in the tsunami zone is an indicator of 

sensitivity.

Information presented in this report will further the 

dialogue on understanding societal risk to tsunami hazards 

in Oregon. Results can be used by public officials to determine where site-specific risk assessments and more-detailed 

tsunami-inundation modeling efforts may be warranted to 

further detail the threats posed by tsunamis to coastal communities in Oregon. Results can also be used by communities, private relief organizations, and emergency and land-use 

managers to augment regional mitigation, preparedness, 

response, and recovery strategies with site-specific efforts 

that reflect local conditions and needs. It is up to managers, 

policymakers, and private citizens to determine where to 

allocate limited risk-reduction resources and attention––to 

the communities with high loss potentials, to communities 

that may be incapable of adapting to the loss of significant 

percentages of their assets, or to a specific demographic or 

economic sector.

Acknowledgments

This study was supported by the “Risk and Vulnerability 

to Natural Hazards” project managed by the U.S. Geological 

Survey’s Geographic Analysis and Monitoring (GAM) program. Mara Tongue, Chris Soulard, Caroline Hermans, Susan 

Benjamin, and Len Gaydos of the USGS, Jay Wilson of the 

Oregon Emergency Management, Pat Corcoran of Oregon Sea 

Grant, Jonathan Allen, George Priest, and Rob Witter of the 

Oregon Department of Geology and Mineral Industries, and 

David Stein of the NOAA Coastal Services Center provided 

insightful manuscript reviews. I would like to thank Gregory 

Tuck from San Jose State University and Alyssia Church 

from The Pennsylvania State University for their assistance in 

analyzing some of the geospatial datasets. Andre LeDuc of the 

Oregon Natural Hazards Workgroup provided insightful comments to improve figure 3.

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Glossary

dependents Individuals who temporarily reside in facilities where they would be dependent on external assistance to 

evacuate and recover, including adult residential care, child 

day care, correctional facilities, hospitals, outpatient-care centers, psychiatric and substance-abuse hospitals, and schools. 

exposure The first component of vulnerability, focusing on 

the amount of an asset (for example, the number of residents 

of a town) within a tsunami-evacuation zone.

resilience The third component of vulnerability, focusing 

on a community’s ability to withstand, absorb, adapt to, and 

recover from losses.

sensitivity The second component of vulnerability, focusing on the relative impact of losses to an entire community 

(for example, the percentage of a community’s workforce in 

a tsunami zone); for population data, it refers to differential 

impacts between demographic groups (for example, differences based on age of individuals or race).

vulnerability The attributes of a human-environmental 

system that increase the potential for hazard-related losses or 

reduced performance; characterized by the exposure, sensitivity, and resilience of a community and its assets in relation to 

stressors, either chronic or sudden (Turner and others, 2003).
34 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

Appendix A. North American Industry Classification System 

The North American Classification System (NAICS) is used to classify economic activity in Canada, Mexico, and the 

United States (U.S. Census Bureau, 2007b). The eight-digit code is read from left to right with the first two digits noting the 

business sector, the third and fourth digits noting the subsector and industry group, the fifth and sixth digits noting particular 

industries, and the seventh and eighth digits (if needed) noting the jurisdictional level (for example, county, State, or Federal). 

The following table summarizes the sector descriptions for the two-digit 2007 NAICS codes.

Sector number Description

11 Agriculture, Forestry, Fishing and Hunting

21 Mining

22 Utilities

23 Construction

31-33 Manufacturing

42 Wholesale Trade

44-45 Retail Trade

48-49 Transportation and Warehousing

51 Information

52 Finance and Insurance

53 Real Estate and Rental and Leasing

54 Professional, Scientific, and Technical Services

55 Management of Companies and Enterprises

56 Administrative and Support and Waste Management and Remediation Services

61 Education Services

62 Health Care and Social Assistance

71 Arts, Entertainment, and Recreation

72 Accommodation and Food Services

81 Other Services (except Public Administration)

92 Public Administration
Appendix A 35

Appendix A—Continued.

In addition to classifying economic activity, the NAICS codes can be used to extract information on critical and essential 

facilities, public venues, and dependent-population facilities. The following is a list of facilities that can be extracted from the 

infoUSA Employer Database. Numbers refer to the eight-digit code of the North American Industry Classification System 

(NAICS) code (U.S. Census Bureau, 2007b). 

Critical Facilities Essential Facilities

Public Order

Police stations

 Federal: 92212002

 Police departments: 92212003

 Sheriff: 92212004

 State Police: 92212005

Fire stations

 County Fire: 92216001

 Local Fire: 92216003

 State Fire: 92216004

Civil Defense

 Civil Defense: 92219001

 County: 92219003

National Security

 Federal: 92811003

 State: 92811007

Gas stations: 44719005

Banks and Credit Unions:

Banks: 52211002

Credit Unions: 52213003

Retail Grocers: 44511003

Courts and legal counsel (group the following)

Municipal courts: 92211001

County courts: 92211001

Federal Courts: 92211004

State Courts: 92211006

City Legal Counsel: 92213001

County Legal Counsel: 92213002

State Legal Counsel: 92213004

U.S. Post Offices: 4911101

Medical Services

Hospitals: 62211002

Outpatient care centers:

 Childbirth education: 62141003

 Pregnancy counseling: 62141005

 Clinics: 62149301

Physician offices: 62111107, 62121003

Ambulance services: 62191002

Government offices:

City government offices: 92111001, 92112006, 92113001, 92119001

County government offices: 92112007, 92111002, 92113002, 92119002

State government offices: 92112008, 92113005, 92119006

Federal government offices: 92112009, 92119003

Government weather offices: 92119000

Utilities

Wastewater treatment:

 City: 92613001

 County: 92613002

Water and sewage companies: 22131003

Gas companies: 22121002, 22121007

Electric companies: 22112202

Public works: 23731004, 23731007

Radio and TV Broadcasting: 51511203, 51512001
36 Variations in City Exposure and Sensitivity to Tsunami Hazards in Oregon

Appendix A—Continued.

Public venues Dependent Populations

Libraries

City: 51912001, 51912002

Federal: 51912003

Institutional: 51912005

Public: 51912006

State: 51912011, 51912010

Shopping centers and malls: 53112008

Colleges: 61131009

Museums: 71211001

Casino: 71329002

Historical Places: 71212001

Botanical Gardens: 71213003

Aquariums: 71219001

Zoos: 71213006

Parks: 71219004

Theaters: 51213101, 71111007

Spectator Sports: 71121203, 71121204

Religious Organizations

Christian Science: 81311005

Church Organizations: 81311006

Churches: 81311008

Clergy: 81311009

Convents and Monasteries: 81311010

Mediation Organizations: 81311011

Mosques: 81311015

Religious Organizations: 81311021

Retreat Houses: 81311023

Spiritualists: 81311025

Synagogues: 81311026

Places of Worship (non-theistic): 81311031

Hospitals: 

Hospitals: 62211002

Mental Health Services: 62221001

Psychiatric treatment facilities: 62221003

Outpatient Care Centers (group the following)

Childbirth education: 62141003

Pregnancy counseling: 62141005

Clinics: 62149301

Offices of physicians: 62111107

Adult residential care 

Adult care facilities: 62311001, 62311002, 62311008

Hospices: 62311011

Nursing homes: 62311016

Nursing home services: 62311018

Rest homes: 62311020

Retirement communities: 62331101

Homes – adult: 62331203

Senior citizens services: 62331205

Residential care homes: 62331206

Sheltered care homes: 62399000

Group homes: 62399007

Foster care: 62399013

Day care centers – adult: 62412002

Child day care

Babysitters: 62441001

Childcare centers: 62441002, 62441003

Pre-schools: 62441005

Nursery schools: 62441006

Schools

Religious schools: 61111004

Schools: 61111007

Schools with special academics: 61111010

Home schooling: 61111016

Colleges: 61131009

Correctional Facilities

City: 92214001

State: 92214002

Federal: 92214003

County: 92214004

Overnight Tourists

Hotels: 72111002

Bed and Breakfasts: 72119101

Inns: 72119102

Cabin Rentals: 72119903

Health resorts: 72119907

Resorts: 72119909

Tourist accommodations: 72119911

Campgrounds: 72121101

Camps: 72121403

Hostels: 72131006

Student housing: 72131009
Appendix B 37

Appendix B. Overview of Project Database 

Additional data on the distribution of assets within specific cities is provided in the database that accompanies this report. 

Database Worksheets—Land Cover, Population, Economy, and Facilities

Information on the amount and percentage of various assets are summarized in four worksheets—land cover, population, 

economy, and facilities. In these four worksheets, rows 3–35 refer to the 26 incorporated cities that have land in the tsunamiinundation zone, as well as the unincorporated portions of the seven coastal counties. Rows 36–42 are county-level summaries 

and rows 43–48 provide descriptive statistics for the region, including study area totals, third quartiles, and maximum values.

In these worksheets, the first four columns identify the city name, a geographic identifier, and the county name. The 

geographic identifier is a number assigned to each jurisdiction, starting at 1 with the City of Astoria and ending with 33 for the 

unincorporated portions in Curry County. Sorting and graphing information by the geographic identifier allows one to graph 

and visualize information in a consistent fashion based on geographic location. The remaining columns in the four note the following for each jurisdiction:

• The amount of an attribute located in the tsunami-inundation zone of a city (“Inundation Zone”);

• The total amount within a city, regardless of the hazard zone (“City Total”); and

• The percentage of an attribute in the tsunami-inundation zone of a city (“City %”), which is derived by dividing

 the “Inundation Zone” amount by the “City Total.” 

Land-cover data refer to the number of 30-meter cells, residential and employee data refer to the number of individuals, parcel 

data refer to 2006 U.S. dollars, and facility data refer to the number of facilities. Demographic data includes an additional 

attribute noted as “% of Total Population in Inundation Zone.” While “City %” notes the percentage of a demographic category 

of a community in the hazard-prone area, “% of Total Population in Inundation Zone” notes the percentage of residents in the 

inundation zone of a city that are a certain demographic group. For example, a “City %” value of 34 in the Hispanic or Latino 

population category indicates that 34 percent of the Hispanic population of a city is in the tsunami-inundation zone. A “% of 

Total Population in Inundation Zone” value of 34 in the Hispanic or Latino population category indicates that 34 percent of the 

residents in the inundation zone are Hispanic. 

Database Worksheet—Business Types

The distribution of business types are summarized in the database worksheet “Business Types.” Rows in this worksheet 

are the 21 industry types, based on the first two digits of the North American Industry Classification System code attached to 

each business in the InfoUSA Employer Database. Information on businesses, employees and sales volume are each sorted by 

business type.