APPLICATION OF THE SNOWMELT RUNOFF MODEL USING MULTIPLE-PARAMETER LANDSCAPE ZONES ON THE TOWANDA CREEK BASIN, PENNSYLVANIA

The Snowmelt Runoff Model (SRM) is designed to compute daily stream di scharge using satellite snow cover data for a basin divided into eleva tion zones. For the Towanda Creek basin, a Pennsylvania watershed with relatively little relief, analysis of snow cover images revealed that both elevation and land use affected snow accumulation and melt on th e landscape. The distribution of slope and aspect on the watershed was also considered; however, these landscape features were not well corr elated with the available snow cover data. SRM streamflow predictions for 1990, 1993 and 1994 snowmelt seasons for the Towanda Creek basin u sing a combination of elevation and land use zones yielded more precis e streamflow estimates than the use of standard elevation zones alone. The use of multiple-parameter zones worked best in non-rain-on-snow c onditions such as in 1990 and 1994 seasons where melt was primarily dr iven by differences in solar radiation. For seasons with major rain-on -snow events such as 1993, only modest improvements were shown since m elt was dominated by rainfall energy inputs, condensation and sensible heat convection. Availability of GIS coverages containing satellite s now cover data and other landscape attributes should permit similar re formulation of multiple-parameter watershed zones and improved SRM str eamflow predictions on other basins.