Development and application of a graphical interface for the TR-55 hydrology model

Abstract

Hydrosim Mk. 1.0 was developed as a graphical interface for the United States Soil Conservation Services; TR-55 watershed model to better examine the effects of land use on runoff and peak discharge for both single and combined watersheds, real or hypothetical. The need for this was the result of a relatively recent increase in sedimentation into Lake Newport, located in Mill Creek Park, Youngstown, Ohio. It is believed that this increase in sedimentation is the result of an increase in runoff and discharge due to development within the Mill Creek watershed.

Hydrosim was used to model a hypothetical watershed to determine what characteristic of a watershed has the greatest impact on runoff and peak discharge. From this model it was determined that the soil composition of the watershed and the type and location of land use change can greatly affect the amount of runoff and peak discharge. It was also determined that the impact of development can be reduced if the development takes place on soils of low infiltration rates as opposed to those of high infiltration rates and care is taken to locate the development within the watershed so as not to decrease the time of concentration. Finally, Hydrosim was used to model Cranberry Run, a portion of the Mill Creek watershed which discharges into Lake Newport, to determine the impact of present development compared to as assumed original land use of woods. The results of the modelling showed an increase in runoff over 95% and an increase in peak discharge of over 100%.