AN APPROXIMATION FOR THE BANK STORAGE EFFECT

A perturbation procedure is used to calculate an approximate flood‐routing solution for the coupled groundwater and open channel flow equations. Seepage is initially neglected to calculate the solution of the linearized kinematic wave equations. The kinematic wave solution is then used to obtain a solution for the groundwater problem, and this groundwater solution is used to obtain a second‐order solution for the flood‐routing problem. The solution has a relatively simple form that is easily applied, and an example suggests that changes created in the downstream hydrograph by bank storage can be of the same order as changes created by retaining all terms in the open channel flow equations and routing the flood down the channel with zero bank storage. Copyright 1990 by the American Geophysical Union.