Variable Parameter Muskingum Routing Considering Downstream Effects

Abstract

Using a variable parameter Muskingum method, a procedure for discharge hydrograph routing in prismatic channels considering downstream effects is presented. The method involves a two step process: (1) a given routing reach is divided into a number of subreaches with each subreach having a representative unique stage–discharge relationship established by using a gradually varied flow profile estimation technique; and (2) the routing of a given inflow hydrograph through these subreaches successively using the variable parameter Muskingum method with parameter variation achieved using the established stage–discharge relationships pertinent to the subreaches and the assumptions of the routing method. The ability of this procedure to route floods accounting for downstream effects is demonstrated by routing a given hypothetical inflow hydrograph in three rectangular channels each with a reach length of