National Assessment of Coastal Vulnerability to Sea-Level Rise: Preliminary Results for the U.S. Atlantic Coast
Discussion
Regional Examples:
Figure 4. Map of the Coastal Vulnerability Index for the New York to New Jersey region. |
Figure 8. Map of the Coastal Vulnerability Index for the North Carolina to Georgia region. |
The data underlying the coastal vulnerability index (CVI) show variability at several spatial
scales. The rate of sea-level rise, and tide range vary over a
spatial scale of >100 km. In the case of sea-level rise, this
represents the large-scale patterns of isostasy and tectonism
present along the Atlantic continental margin of North America
(Peltier, 1996; Braatz and Aubrey, 1987). Changes in tide range
generally reflect changes in the configuration of the continental
shelf as a whole (e.g., shelf width).
A second group of variables, consisting of geomorphology and
wave height, vary on a ~10 km scale that reflects primarily the
landward changes in environments and energy in the coastal system.
For example, there is a nearly continuous chain of barrier islands
backed by estuaries and lagoons along the open-ocean coast from
eastern Long Island, New York to the Florida Keys.
The shoreline erosion/accretion rates vary on a spatial scale
equal to the minimum size of our grid, which is 3 minutes or ~6 km.
It is this variable which adds the greatest variation to the CVI
values. As described above, this is also the variable in our data
set that is the least well-documented.
Regional Examples
To highlight the nature of the CVI and its underlying data,
different index variables from two geographic regions are presented
on the next two pages:
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