Hydrologic and water quality modeling with the Hydrological Simulation Program-Fortran (HSPF) involves managing large volumes of data. Among that data are parameters describing watershed characteristics, which often are derived from Geographic Information Systems (GIS) layers such as subbasin boundaries and land uses. Other parameters specify simulation options within HSPF. All of these parameters are input to HSPF by means of a text file, known as the User Control Input (UCI) file, containing a series of tightly formatted records. The values on the records must be formatted precisely, and the records must themselves be arranged in a preordained order for HSPF to understand.
WinHSPF was designed as an interactive Windows interface to HSPF. WinHSPF assists the user in building UCI files from GIS data, especially data from the US Environmental Protection Agency’s BASINS system. After the UCI file is built, WinHSPF is used to view, understand, and modify the model representation of a watershed. The Fortran program HSPF can be run from within WinHSPF. A given UCI file can be modified and saved by another name, thus creating model simulation scenarios. Within the BASINS system, WinHSPF is intended to be used in conjunction with the interactive program known as ‘GENeration and analysis of model simulation SCeNarios’, or GenScn. GenScn allows the user to analyze results of model simulation scenarios and compare scenarios.