Determination of Clark’s Unit Hydrograph Parameters for Watersheds

This article explains the application of search algorithms to determine the parameters for Clark’s unit hydrograph. The golden section search algorithm and discrete horizontal line search method were applied to a composite unit hydrograph developed for a watershed. The methodology developed here was applied to watersheds near Buckeye, Arizona, Fort Worth, Texas, and San Antonio, Texas. The only difference in determining the Clark’s unit hydrograph parameters for these watersheds was the time-area relationships. This relationship for Texas watersheds is different than that for Arizona watersheds. Resulting ordinates of Clark’s unit hydrograph are comparable to the derived composite unit hydrograph.