Water Resources Research Act Program

Principal Investigators: David Morris

Abstract: Accurate and precise rainfall data with high spatial and temporal resolution are critical to a broad spectrum of public sector, private sector, and academic pro jects of great interest to Caribbean prosperity, yet such data are presently lacking in the USVI. Residential water supply construction (cisterns), drainage planning for public works pro jects, and environmental erosion studies, to name only a few applications, all rely on an accurate understanding of the actual and predicted rainfall rates at varied sites around the USVI. While historical data are available online through the US Geological Survey website, these data are, themselves, derived from only a few collection sites around the VI and are now some 20-40 years old. As global climate change drives variation in weather patterns across the Caribbean, it is critical to the next generation of construction and development planning in the USVI to build and maintain a modern, high-resolution precipitation database that accurately portrays the current microclimate conditions across the region. Similar data are available across urban and rural areas throughout the continental US and should be made available as well in the USVI. To meet this need, a high-density network of low-cost tipping-bucket rain gauges will be built and installed across the island of St. Thomas to provide continuous monitoring of rainfall rates and accumulation. These rainfall stations will be monitored and maintained by a team comprising both University of the Virgin Islands (UVI) faculty and undergraduate researchers and will span all the ma jor microclimates of St Thomas to provide both local rainfall data within each microclimate region and a dynamic picture of the evolution of rainfall events as they cross the island and encounter its varied topology. Data will be archived at UVI on a publicly accessible web-server and will be distributed to federal agencies including the National Climatic Data Center and US Geological Survey as appropriate. These data will be of immediate value to water resource planners around St Thomas and the Caribbean at large and will meet a need for accurate rainfall data to support ongoing regional erosion studies. The high spatial resolution data collected by this program will represent the first of its kind in the Caribbean (with spatial resolution of 1 km) and will become one of only a handful of such research-grade datasets available worldwide. As such, the data collected will address not only local water resource issues but long-standing issues in atmospheric microphysics including the nature of the statistical distribution of rainfall rates within an individual storm and whether commonalities exist in the evolution of rainfall rates across all storms.