Beach erosion studies on tropical islands are often problematic because of the lack of quantitative data. Historical maps and charts are usually of too poor resolution for use in shoreline change measurements, and aerial photographs are sometimes similarly constrained. Furthermore, the high reflectance of the white carbonate sand makes it difficult to properly interpret the high-water line as the shoreline indicator on aerial photography. While hurricanes can cause dramatic changes in beach dimensions on tropical islands within the tropical storm belt, the long-term trend is often quite small (e.g., frequently one foot or less of erosion per year).
