Summary The homogenization method by asymptotic expansions was used to study water flow in a double-porosity soil. The gravity effect is included. The macroscopic flow model was found to be a single diffusion-type equation with two effective parameters. The effective conductivity tensor is defined as depending on the solution of a local boundary value problem within a period. The effective specific water capacity is found to be the volumetric average. Both parameters are functions of the capillary pressure head. A numerical example of water infiltration into initially dry soil is presented. The results of homogenization show good agreement with the reference fine scale solution
