A Distributed Linear Representation of Surface Runoff

Abstract

A distributed quasi-linear model of direct catchment runoff is developed consisting of cascades of linear reservoirs connected by linear channels. By fitting to the kinematic wave, the model parameters are expressed in terms of the physical characteristics of the catchment and the impulse response function is constrained to be input-dependent. Separate models of overland flow and stream flow are developed facilitating consideration of spatially variable inputs. Investigation into the sensitivity of the catchment to distributed inputs illustrates the failure of the kinematic wave method to provide realistic hydrograph dispersion when applied to the flood-routing problem.