Simulation of local lnfiltration-redistribution-reinfiltration into layered soils

摘要

The problem of determining the local infiltration of rainfall in to soils characterized by not homogeneous vertical profile is investigated under the condition of pre-existing wetting front which does not allow to apply the conceptual model earlier developed for infiltration starting from initial soil water content constant with depth. Crusted soils and two-layered sois where either layer may be less permeable are considered. Numerical solutions of the Richards equation are used in order to understand as the shape of the soil water profiel progresses with time. The results indicate that the considered process can lead to significant distorsions in the shape of the water content profiel and, therefore, a conceptual approach for refinfiltration should be developed by adopting a composite profile scheme in both layers, along the main lines earlier proposed by (5) for the simpler case of a vertically homogeneous soil.