COMPARISON OF PHYSICALLY-BASED MUSKINGUM METHODS.

Three physically-based methods of estimating Muskingum channel routing parameters are compared and discussed. The three methods are (a) channel storage, (b) diffusion wave, and (c) dynamic wave. Theoretical similarities and differences are examined. The accuracy of the three methods is evaluated by comparing their predicted values to those obtained by the St. Venant equations for 47 differnt flow conditions and to those observed in two natural channels. The dynamic wave and diffusion wave methods predicted essentially the same outflow hydrographs for all of the simulations. For the St. Venant tests, the range in peak inflow rate was 25 to 2000 m**3/s, the range in time to peak was 0. 25 to 48 h, range in the ratio of peak to base flow was 0. 005 to 0. 5, the range in slope was 0. 0001 to 0. 01 and the range in channel widths was 20 m to 100 m. Additional study results are discussed.