Nonlinear mathematical model of the junction of tidal rivers

摘要

An attempt is made to study a nonlinear mathematical model for the description of tidal flow propagation at the confluence of two tidal rivers. The model so developed requires no additional approximations than what is usually accepted in the case of a single channel without branching. To illustrate the effectiveness of the model, the flow conditions at the confluence of the river Hooghly and the river Rupnarain have been determined. The explicit finite difference scheme is used for its simple mathematical formulation and easy computer programming, also keeping in mind the sharp turn-over of the tidal curves of the Hooghly and the Rupnarain, which is difficult to be reproduced using the implicit finite difference schemes. It is of interest to note that not only the junction of two rivers but also of any number of rivers can easily be simulated with this method. Also, the junction of several rivers at several points along a river can be simulated using the same procedure advanced in this paper. The accuracy of tidal computation is verified by checking the results of the model against the data observed in the above-mentioned river system.