Soil Hydrological Studies for Water Resource Conservation and Management in the Virgin Islands

Abstract

The Virgin Islands face water scarcity due to their small size, topography, and the prevailing climate of the northeastern Caribbean region. At the same time, demands placed on water resources are high, from tourism, population growth, and a stated desire to expand agricultural production. With limited land and freshwater resources, it is imperative that managers have scientific information for decision-making, but soil hydrology in the Virgin Islands has been poorly described. Soil hydrology, the application of soil physics to the fluxes of water through soil, can provide insight into various areas of need: the management of soil water in agriculture, mechanistic understanding of surface runoff and island water budgets, and soil erosion by water. Soil hydrological studies in the Virgin Islands can, therefore, help address the need for water resource conservation and data-driven management at various scales.

This dissertation is composed of three studies of soil hydrological questions. The uniting theme across all three is an attempt, with limited existing datasets, to better describe relevant soil hydrological questions that will ultimately improve water conservation methods in the Virgin Islands. After a literature review of the broad topic of Virgin Islands water resources, we first examine the soil hydrological implications and water balance of agricultural mulch covers in the production of a plantain crop at the plot scale. In the second study, we examine runoff generation mechanisms at the watershed scale and consider the implications of runoff coefficients and connectivity in a Virgin Islands watershed. In the third study, we describe the remaining challenges in parameterizing an erosion prediction model at the watershed scale in the Virgin Islands and Caribbean region.