Coastal Vulnerability
Predicting a coastline's vulnerability to change is difficult because many factors are involved. No standard method is used by scientists to predict coastal change. In order to address these problems, the U.S. Geogical Survey (USGS) is implementing a fairly simple classification of the relative vulnerability of different coastal environments to future rises in sea level. Through the use of a coastal vulnerability index or CVI, the relative risk that physical changes will occur as sea-level rises is quantified based on six criteria.
- Tidal Range
- Wave Height
- Coastal Slope
- Shoreline Erosion Rates on a per segment basis
- Geomorphology on a per segment basis
- Historic Rates of sea-level rise on a per segment basis
The approach combines a coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, and yields a relative measure of the system's natural vulnerability to the effects of sea-level rise.
The Geological Survey of Canada (GSC) has also been developing its own sensitivity index, which is a modified version of the coastal vulnerability index of Gornitz (1990). This sensitivity index is obtained by manipulating scores of 1 to 5 attributed to each of seven variables:
- Relief
- Geology
- Coastal Landform
- Sea-Level Tendency
- Shoreline Displacement
- Tidal Range
- Wave Height