A nonlinear hydrologic cascade is developed for simulation of watershed runoff. The cascade consists of three nonlinear storage elements. The parameters of these elements are determined by optimization by the modified Rosenbrock-Palmer algorithm. An attempt is made to correlate these parameters with the watershed physiography but the correlations are not encouraging.

Using the optimized parameter values hydrographs are predicted for a number of events on a number of natural agricultural watersheds. The predicted hydrographs are in good agreement with the observed hydrographs and indicate that the cascade performs well in prediction of runoff.

Project No. 3109-206