Development of Optimal and Physically Realizable Unit Hydrograph

Abstract

Optimization techniques for deriving a unit hydrograph (UH) have received considerable attention. But the UHs derived in some studies are not physically justifiable as the recession limb has a wavy shape. This study extends an existing optimization model by introducing additional constraints to ensure a monotonic decline in the recession limb of the UH. Although there is a marginal deterioration of the objective function, the shape of the developed UH is physically correct. Moreover, the match between the observed and computed direct surface runoff hydrographs is close.