Reverse Routing of Flood Hydrographs Using Level Pool Routing
Christopher Zoppou
Abstract:
In level pool routing, which is the simplest hydrological
routing method, the downstream discharge may be expressed explicitly in
terms of the inflow and the channel or reservoir characteristics. The level
pool routing equation can also be used to estimate the inflow hydrograph
given the outflow hydrograph and the water level in the reservoir.
Unfortunately, the use of traditional level pool routing method, which is
based on the implicit finite difference scheme for reverse routing has been
unsuccessful, despite the simplicity of the problem. If a simple explicit
centered differencing scheme is used instead for simulating the inflow
hydrograph, then the problems associated with traditional schemes, which
require the application of filtering techniques, are bypassed. This is
demonstrated using a realistic hypothetical example and a case study. The
explicit scheme results are comparable in accuracy to results from the
implicit scheme without resorting to the use of filtering techniques. The
simple explicit scheme produces a direct solution to the problem and should
be the preferred method for both level pool and reverse level pool routing.