REDISTRIBUTION OF WATER AND SOLUTE FOLLOWING INFILTRATION FROM A SURFACE DRIP SOURCE

Laboratory observations of the redistribution of water and solute, following one-dimensional and three-dimensional constant flux infiltration, reveal distinctly different paterns of water and chemical transport. The geometry-induced enhancement of capillarity over gravity in three dimensions is thought responsible for the rapid attainment during redistribution of a near-constant water content theta*, some radial distance r around the dripper. This renders simple the prediction of the maximum radial extent of convective solute redistribution, r*. Nevertheless, molecular diffusion about r* is the dominant mode of solute transport during the weak convective redistribution in three dimensions.