U.S. Geological Survey
Coastal and Marine Geology
Woods Hole Field Center

Back to Graphics Version


National Assessment of Coastal Vulnerability to Sea-Level Rise: Preliminary Results for the U.S. Pacific Coast

Table of contents
Web Site Title Page
Introduction
Risk Variables
Data Ranking
Coastal Vulnerability Index
Results
Discussion
Summary
References


Table 1.

Ranking of coastal vulnerability index variables for the U.S. Pacific Coast.

Figure 1.

Map of the Coastal Vulnerability Index (C.V.I.) for the U.S. Pacific coast. The C.V.I. shows the relative vulnerability of the coast to changes due to future rise in sea-level. Areas along the coast are assigned a ranking from low to very high risk, based on an analysis of physical variables that contribute to coastal change.

Figure 2.

Histograms showing the frequency of occurrence and cumulative frequency of C.V.I. values for the U.S. Pacific coast. The vertical red lines delineate the chosen ranges for low, moderate, high, and very high risk areas.

Figure 3.

Bar graph showing the percentage of shoreline along the U.S. Pacific coast in each risk category. The graph also shows the total length of shoreline (in kilometers) in each risk category. The total length of mapped shoreline in this study is 3987 km.

Low: 804 km
Moderate: 1108 km
High: 875 km
Very High: 1100 km

Figure 4.

Map of the Coastal Vulnerability Index for the open ocean coast of southwestern Washington and northwestern Oregon.

Figure 5.

Map of the coastal slope variable for southwestern Washington and northwestern Oregon. The coastal slope is relatively steep (low risk) in northwestern Oregon, but is quite low (high risk) in southwestern Washington.

Figure 6.

Map of the geomorphology variable for southwestern Washington and northwestern Oregon. The open-ocean shoreline is composed predominantly of high-risk sandy pocket beaches interspersed with low-risk rocky headlands; to the north of Tillamook Head there is a long stretch of very high-risk sandy beach.

Figure 7.

Map of the shoreline erosion/accretion rate variable for southwestern Washington and northwestern Oregon. The smaller-scale variations in the C.V.I. values (see Figure 4) are influenced primarily by changes in shoreline erosion rate.

Figure 8.

Map of the Coastal Vulnerability Index for the San Francisco - Monterey region.

Figure 9.

Map of the tide range variable for the San Francisco - Monterey region. The tide range is generally lower than 1.28 m (high to very high risk), except for the area between Half Moon Bay and La Selva Beach where the tide range increases to ~1.5 m.

Figure 10.

Map of the coastal slope variable for the San Francisco - Monterey region. The coastal slope is relatively steep (low risk) in the Monterey region and at the rocky headlands to the south of San Francisco, but is quite low (high risk) at the open ocean coast at the mouth of San Francisco Bay.

Figure 11.

Map of the geomorphology variable for the San Francisco - Monterey region. The shoreline is composed of higher-risk sandy pocket beaches interspersed with lower-risk rocky headlands, as well as areas of low sea-cliffs and high coastal bluffs.


Contents > Back to Top

Introduction > Risk Variables > Data Ranking > CVI > Results > Discussion > Summary > References
This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.

[an error occurred while processing this directive]