Water Resources Research Act Program

Principal Investigators: Colin Finney, Denise Rennis, Henry Smith

Abstract: In the U.S. Virgin Islands, housing, roads, and commercial and industrial development are increasingly replacing natural terrestrial environments such as grasslands and forests. Development activities and associated non-point source pollution, however, have been suggested as being a primary cause of coral reef degradation in coastal areas. One of the principal effects of development and urbanization is the conversion of pervious surfaces into impervious surfaces. Research over the past two decades has indicated that increased quantities of impervious surfaces are closely associated with environmental degradation, with the amount of impervious surfaces in a watershed being inversely correlated with the health of that watershed. Regularly classifying and quantifying land cover within watersheds, particularly the amount of impervious surfaces, is, therefore, important in monitoring the health of watersheds, and using sophisticated techniques, such as landscape-specific infiltration coefficients, classification mapping and change analysis software, allows for a more in-depth analysis of impacts. Use of this information to improve monitoring programs and management decisions should lead to more sustainable land-use and land management practices. The goal of the proposed study is to use impervious surface analysis as a methodology for effectively monitoring and managing water quality and habitat health of a watershed and to apply this as a case study to one or more of the watersheds affecting the EEMP where non-point source pollution from incompatible upland development has been identified as a major threat. The objectives of the study are to: 1. Establish land-use categories that are consistent with the U.S. Virgin Islands landscape and currently used land-use categories by coordinating with the Department of Planning and Natural Resources (DPNR) and the National Oceanic and Atmospheric Administration (NOAA); 2. Establish baseline and current datasets of impervious surface cover within one or more of the terrestrial watersheds draining to the EEMP using remote sensing; 3. Execute a change analysis of impervious surfaces using historical and current remote sensing imagery and classification mapping; 4. Document a protocol for monitoring changes of impervious surfaces, based on the terrestrial watershed (s) draining to the EEMP, to enable land managers to assess land-use changes and focus on areas for protection and/or restoration; 5. Provide an educational brochure for minimizing impacts due to impervious surfaces which could be disseminated to private landowners and other members of the community through the Cooperative Extension Services of the University of the Virgin Islands. To accomplish these objectives, the study will consist of seven tasks: 1) Collaboration with DPNR and NOAA and establishment of land-use categories; 2) Evaluation of USVI-specific impervious surface infiltration coefficients; 3) Historical baseline data collection; 4) Current data collection and classification mapping; 5) Field data collection and ground-truthing; 6) Change analysis; and 7) Identification of impact minimization and brochure design.