ABSTRACT 97-26862 Hopkinson W/WS: Integrated, ecological-economic modeling of watersheds and estuaries at multiple scales The objective of this research is to integrate socioeconomic models with spatially explicit models of land use, ecosystem biogeochemistry and watershed hydrology to provide comprehensive assessments of human activities on nutrient, sediment and water fluxes for the Ipswich watershed in coastal Massachusetts. An additional objective is to develop approaches that will allow application of these models to other watersheds. To assess human impacts on watershed dynamics, the investigators will use four types of models: socioeconomic, land-use change, hydrologic and stream biogeochemical. A key goal is to develop a means of assessing the impacts of urbanization and land-use change on watersheds and estuarine ecosystems in general, not just a specific assessment for the Ipswich River. The approach will enable the researchers to better assess human impacts on watersheds and to evaluate management strategies for minimizing or reversing watershed, riverine and estuarine degradation.