Multilinear muskingum flood routing method

Abstract

In a study of multilinear modelling of flood wave propagation based on a time distribution scheme, an attempt is made to overcome certain limitations of the currently available multilinear models. The physically based Muskingum method is used as the linear sub-model. Unlike the currently available multilinear models, wherein the parameters are held constant for routing prescribed flow zones of the inflow hydrograph, in the proposed method they vary at each routing time step. This allows better modelling of the non-linear behaviour of the flood wave movement and eliminates the subjectivity of deciding on the number of flow zones to be used for routing the given inflow hydrograph. The suitability of this method for routing floods in wide uniform rectangular channels without lateral flow is studied using hypothetical data. The study reveals that the proposed method is capable of describing flood wave movement in open channels, as a result of a flood hydrograph characterized by narrow loop rating curve.