Oscillation phenomena in gravity‐driven drainage in coarse porous media

Abstract

Correlations between rainfall amount and water content in coarse soils were studied. Situations were registered in which the intensity of the gravity‐driven flow in the soil exhibited irregular oscillations which could not be explained within the scope of the standard Richards' theory. The problem was analyzed by means of a set of laboratory experiments. It seems that the observed global (macroscopic) oscillations can be qualitatively explained as a result of correlated behavior of the local (microscopic) flows. The search for a satisfactory quantitative description of those effects promises to be a field of useful and interesting research activities.