A research project is being proposed to study the relationship between land use and the hydrology of the Southern Aquifer between Santa Isabel and Salinas, Puerto Rico. Land use change in the area will be studied from 1930 to present. The water cycle will be carefully studied in there areas of different land use in the Santa Isabel area: forest, urban, and active cropland. The proposed research will built on the existing hydrologic knowledge generated by the United States Geological Survey (USGS). Because socio-economical factors typically drive water and land use decisions, a socio-ecological approach will be applied to assess community-perceptions on natural resources valuation.