Determination of Optimal Loss Rate Parameters and Unit Hydrograph

Abstract

Reduction in deviation between predicted and observed runoff ordinates, and accurate estimation of loss rate parameters, have received considerable attention from many researchers. Linear programming is an optimization tool that is being used to determine the optimal unit hydrograph for a watershed from observed rainfall-runoff data, but requires the rainfall losses a priori. Nonlinear programming models overcome this problem but require good initial values of decision variables. The method presented herein determines the optimal loss rate parameters and unit hydrograph using infiltration theory, unit hydrograph theory, and linear programming. A comparison of the results with previous methods shows the better predictive capability of the model.