It is described below also. Erosion and Sedimentation on St. John, Virgin Islands Preliminary research on the island of St. John has suggested that erosion from the rapid development of both public and private lands is the single greatest threat to the coral reefs and other offshore marine resources. Effective land use planning can only take place if there is a basic understanding of runoff and erosion rates at the plot, hillslope and small catchment scale. Of particular interest is the highly variable amount of sediment storage on the hillslopes, the different sequences of storms that tend to saturate varying areas of the island, and the very different responses in runoff volumes to different storm sizes. Current prediction tools have been largely developed in agricultural areas in the eastern and central United States, and there is an urgent need to calibrate these models to the dry tropics.
Islands tend to have high population densities and land processes linked intimately to the ocean.
Very steep slopes and complex geology in the eastern Caribbean are combined with an exceptionally variable hydrologic regime. These unique environmental conditions mean that much of the existing data and modeling efforts from the mainland United States cannot be directly applied. A well-documented data set on runoff, erosion and sediment movement at different scales will provide planners with information to evaluate and calibrate new models and predictive tools.