The capillary effects on water percolation in homogeneous snow

A theoretical basis for introducing capillary effects into the theory of water percolation through snow is given. A capillary pressure-liquid saturation relationship found in the laboratory is used together with the theory to make a quantitative examination of capillary effects. It is shown that capillarity accounts for less than 10% of the total force when water flux is 10–8m s–1although the percentage rapidly increases for smaller fluxes. The experiments suggest that the irreducible water content of dense snow is 7% of the pore volume. It is concluded that the wave-front diffusion seen in lysimeter studies is not the result of capillary action. Other possible causes are suggested.