Evaluation and Application of a Digital Hydrologic Simulation Model to an Idaho Watershed

Watershed simulation models have many engineering applications in the areas of research and project planning and management. In this study the Kentucky watershed Model, a Fortran version of the Stanford Watershed Model, was adapted for use in Idaho. The model was applied and evaluated on the Palouse River near Potlatch, Idaho, a 317 sq.ml. watershed in northern Idaho. Daily flows were synthesized and plotted against recorded flows for the 1967-1968 and 1969-1970 water years. The synthesized annual water yield was found to be 7.34 and 13-59 inches respectively versus recorded values of 3.68 and 12.05 inches. A tendency to underestimate peaks early in the runoff season and to underestimate the spring recession was also observed. An adjustment to the valley precipitation estimate was made to account for orographic influences on the amount of precipitation received in the upper mountainous region of the watershe