EVALUATION OF MULTI-LINEAR CHANNEL ROUTING METHODS

Abstract

The main objective of the present study is to carry out the performance evaluation of the multilinear channel routing methods. Three models were selected for the study which includes the Multilinear Muskingum Method, the Multilinear Discrete Cascade Model and the Multilinear Diffusion Analogy Model. Performances of the models are evaluated by checking the ability of the models to reproduce the benchmark solutions. A hypothetical inflow hydrograph was used for the routing process in a set of trapezoidal channels characterized by different bed slopes and Manning's roughness coefficients. World Meteorological Organization (WMO) has proposed various statistical criteria for the model evaluation. By adopting these criteria the performance analysis was carried out. The results of routing using the selected models show the accurate volume conservation ability of the multilinear models. The multilinear Muskingum model obtained an efficiency of 99.9% in almost all the channels, the multilinear discrete cascade model has more than 98% efficiency and the multilinear diffusion analogy model reproduces the St. Venant solutions with an efficiency more than 99%. Based on these numerical experiments and analysis of results, it is recommended that the multilinear Muskingum method may be used for routing in channels characterized by a bed slope of So > 0.0005 and for channels characterized by So < 0.0005 one may use the multilinear diffusion analogy model routing. As the multilinear discrete cascade model is not able to perform better than the multilinear Muskingum and the multilinear diffusion analogy model, the same is not recommended for routing in channels and rivers.