In this paper, details of a conjunctive surface-subsurface numerical m
odel for the simulation of overland flow are presented. In this model,
the complete one-dimensional Saint-Venant equations for the surface f
low are solved by a simple, explicit, essentially non-oscillating (ENO
) scheme. The two-dimensional Richards equation in the mixed form for
the subsurface flow is solved using an efficient strongly implicit fin
ite-difference scheme. The explicit scheme for the surface flow compon
ent results in a simple method for connecting the surface and subsurfa
ce components. The model is verified using the experimental data and p
revious numerical results available in the literature. The proposed mo
del is used to study the two-dimensionality effects due to non-homogen
eous subsurface characteristics. Applicability of the model to handle
complex subsurface conditions is demonstrated. (C)1998 Elsevier Scienc
e Limited. All rights reserved.