Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

The Hydrological Simulation Program-FORTRAN (HSPF) represents discharge using function tables (FTABLES) that relate stream stage, surface area, volume, and discharge. In this study, five FTABLE scenarios were compared to assess their effect on various outputs predicted using HSPF. Four field-based FTABLE scenarios were developed using detailed cross-sectional surveys. A fifth digital-based FTABLE scenario was developed using digital elevation data and Natural Resources Conservation Service Regional Hydraulic Geometry Curves. Pair-wise Students t-tests were used to compare long-term average instream fecal bacteria concentration and instream fecal bacteria die-off. The digital-based FTABLE scenarios produced significantly higher long-term average instream fecal bacteria concentrations and significantly lower instream fecal bacteria die-off. These differences are function of FTABLE generation method and are an artifact of differences in the digital- and field-based volume-discharge relationships that HSPF uses to compute hourly discharge rates.