Results

The CPI values calculated for GBNPP range from 1.83 – 28.28. The mean CPI value is 5.84; the mode and the median are 3.16. The standard deviation is 5.03. The 25th, 50th, and 75th percentiles are 2.6, 3.5 and 8.0, respectively.

Figure 13 shows a map of the coastal change-potential index for GBNPP. The CPI scores are divided into low, moderate, high, and very high change-potential categories based on the quartile ranges and visual evaluation of the data. CPI values below 2.6 are assigned to the low change-potential category. Values from 2.6 to 3.5 are considered moderate change-potential. High change-potential values lie between 3.51 and 8.0. CPI values above 8.0 are classified as very high change-potential. Figure 14 shows the percentage of GBNPP shoreline in each change-potential category. Nearly 1900 km (1,180 miles) of shoreline is evaluated along the GBNPP. Of this total, twenty-one percent of the mapped shoreline is classified as being at very high change-potential due to future sea-level change. Twenty-five is classified as high change-potential, twenty-four percent as moderate change-potential, and thirty percent as low change-potential.