Reply [to “Comment on ‘An investigation of the relationship between ponded and constant flux rainfall infiltration’ by A. Poulovassilis et al.”]

Dooge and Wang [this issue] have questioned the exactness of some conclusions and results presented by Poulovassilis et al. [1991]. Part of their criticism is based on the results given by the analytical solution with D or K or both constant, where D and K are the diffusivity and hydraulic conductivity ofthe porous body, respectively. Thus they use the solution with K and D constant [Carsla•v anti Jaeger, 1948], Burgers' solution with D constant and K a quadratic function of the water content 6) [Philip, 1974; Clothier et al., 1981] and the solution with K constant and D a Fujita function of © [Fujita, 1952; Sander et al., 1986]. One may express here the reservation which is generally accepted [e.g., Philip, 1969, 1988] that although such solutions can provide an insight, as far as the development of the wetting process is concerned, and in some cases approximate integral properties when D and K are properly matched, they do fail to reproduce the phenomena s frithfully as the physics of the processes require. One must stress here that the imposition of constant D or K or both in the case of flux-controlled infiltration not only distorts drastically the hydraulic properties, which applies for the case of flooding too, but in addition the infiltration features prevailing at the infiltration surface, where D and K are both functions of infiltration time and rainfall rate in contrast with the flooding case where D and K retain at z = 0 their maximum values.