Kinematic subsurface stormflow

Abstract

This paper builds on the analysis of Henderson and Wooding (1964) in comparing simplified models of subsurface stormflow for the case of a sloping soil mantle in which the hydraulic conductivity is constant throughout. It is shown that models based on a kinematic wave formulation may be good approximations for those based on the extended Dupuit‐Forchheimier assumptions for values of the nondimensional parameter λ = 4 i cos θ/( K sin 2 θ) less than about 0.75 in terms of predicting both water table profiles and subsurface stormflow hydrographs. By using this critical value of λ the range of values of slope angle and saturated hydraulic conductivity for which the kinematic approximation is valid can be specified. A comparison is made with slope angles and hydraulic conductivities at field sites where subsurface stormflow has been shown to be an important component of catchment storm response. It is concluded that the kinematic approximation may be useful for cases of practical interest.