As cities continue their reliance on sources of potable water from outside watersheds, issues regarding stewardship of these water supply watersheds arise. In the New York City Croton supply watershed, issues involving contaminant fate and transport have resulted in the need for deterministic models to understand the sources and sinks of water quality contaminants. This study looks at input land use data issues involved in producing an accurate quantitative model of water runoff. The model used is Hydrological Simulation Programs in Fortran for Windows (WinHSPF). In order to find out what qualities the optimum input land use data set should have, a variety of data sets are evaluated. Aerial photo and satellite based land use data sets available publicly at nominal cost are tested against a high ground-resolution aerial photo data set contracted for this study. Variables tested include percent impervious cover and hydraulic connectivity. Model output using various data sets is discussed. |