Parameter estimation of the muskingum channel flood-routing model in ungauged channel reaches

The Muskingum model is one of the most popular models for hydrologic channel flood routing. However, as the parameters of this model are estimated by analyzing both inflow and outflow data, the application of this model to an ungauged channel reach has been limited. In this study, as a solution to this problem, a methodology is proposed to estimate the parameters of the Muskingum model using the basin characteristics representing the inlet and outlet of the channel reach. That is, the Muskingum model could be expressed as a combination of the linear reservoir model and the Dirac delta function, whose weighting factors are determined as a function of the Muskingum model parameter x. It was also found that the storage coefficient of the linear reservoir model is expressed by both the Muskingum model parameters x and K. Finally, it was shown that the Muskingum model parameters can be estimated using the information of concentration time and storage coefficient representing the inlet and outlet of the given channel reach. In the application example with the observed data from the dam discharge experiment in the Geum River Basin, Korea, it was shown that the Muskingum model parameters could be reasonably estimated to be very close to those estimated by the conventional graphical method.