Analyzing watershed hydrologic response changes using a prototype decision-making support system

A prototype decision support system (DSS) has been developed to assist civil infrastructure administrators in the process of issuing construction permits for development projects within flood prone areas. A DSS was developed and implemented through the creation of a Hydrologic Graphical User Interface (HGUI). This program was created using Visual Basic language and makes possible the interaction between a database generated through GIS-Arc/Info techniques and the HEC1 hydrologic computer model.;The Rio Piedras watershed in Puerto Rico was selected for the modeling process. This is a small basin under a rapid urban development. Hydrologic simulations for three years conditions of the drainage basin were considered (1977, 1988 and 1993 land uses conditions). The HGUI was used to process the databases for these conditions and for recalculating the Curve Number parameter, due to the land use changes. The new input data for the HEC-1 is preprocessed and the HEC-1 executed through the HGUI, which finally shows the hydrologic response of the watershed. The watershed response showed an increase in peak flow results through the years. Peak flow difference from years 1977 to 1988 was higher than from years 1988 to 1993, but peak flow increment was higher from 1988 to 1993 due to the difference in years, which is five years for 1988 to 1993 and eleven years for 1977 to 1988.;The HGUI allows the user to change land use to represent proposed urban development projects. If the project does not adversely affect the watershed hydrology, the database is kept up to date through the HGUI, continuously reflecting the changes made to the watershed for new approved land uses. (Abstract shortened by UMI.)...