Abstract: | Many environmental applications of shallow water flow modelling can be characterized as only slowly varying and everywhere sub‐critical. A simplified finite volume model is therefore developed that is capable of describing pertinent shallow water flow processes more efficiently than the usual Godunov/ Riemann characteristics approaches. The model is tested against a number of analytical and numerical solutions to the governing equations. The model reproduces accurately flow round a circular bend, flow over topography, flow up an initially dry beach and floodwave propagation down a meandering river reach, with mass conservative solutions. Copyright © 2004 John Wiley & Sons, Ltd. |