DATA RANKING SYSTEM

Table 1 shows the six variables described in the Introduction, which include both quantitative and qualitative information. Actual variable values are assigned a vulnerability ranking based on value ranges, whereas the non-numerical geomorphology variable is ranked qualitatively according to the relative resistance of a given landform to erosion. Shorelines with erosion/accretion rates between -1.0 and +1.0 m/yr are ranked as moderately vulnerable with increasingly higher rates of erosion or accretion given correspondingly higher or lower vulnerability rankings. Regional coastal slopes range from very high vulnerability, <4.56 percent to very low vulnerability at values > 14.7 percent. The rate of relative sea-level change is ranked using the modern rate of eustatic rise (1.8 mm/yr) as very low vulnerability. Since this is a global or "background" rate common to all shorelines, the sea-level rise ranking reflects primarily local to regional isostatic or tectonic adjustment. Mean wave height rankings range from very low (<1.1 m) to very high (>2.6 m). Tidal range is ranked such that microtidal (<1 m) coasts have very high vulnerability and macrotidal (>6 m) coasts have very low vulnerability.

Table 1: Ranges for Vulnerability Ranking of Variables on the Pacific Coast.