This is a revised application of a proposal to determine the feasibility and effectiveness of using remote sensing technology for large scale surveillance of ecological conditions, altered by human interventions, that may provide habitat for amphibious snails. These snails are central to the transmission of human schistosomiasis in Sichuan and Jiangxi Provinces of China. This project will validate preliminary analyses of ground and satellite data suggesting that Oncomelania hupensis habitat can be identified from Landsat TM imagery. Subsequently, efforts will be made to make the classification more precise by supplementing these data with ecological and landscape data and to evaluate alternative remotely sensed data for their ability to predict risk areas.