A kinematic wave model for rivers with flood plains and other irregular geometries

A general kinematic wave model for flood propagation is presented in the form of a scalar conservation law. The corresponding flux function is convex or nearly convex for regular cross-sections of the river. In the presence of pronounced irregularities, however, convexity may fail. Qualitative consequences of the shape of the flux function for typical irregularities are discussed, particularly for rivers with flood plains and rivers trapped in canyons.