ABSTRACT
Over longer timescales, chemical denudation rates and their relationship to soil and slope profile evolution are the primary concern of the geomorphologist, but such studies of landform evolution must clearly be firmly based in process theory if rigorous explanation is to be achieved. Although the study of runoff processes is a necessary prerequisite, processes of solute uptake must also be investigated to improve understanding of the pattern of chemical denudation on a hillslope and the associated pattern of soil profile development. Given a knowledge of solute processes, two timescales exist for investigation. Soil anisotropy, caused by a less permeable soil horizon at depth or by impermeable bedrock, is, however, crucial to the generation of lateral subsurface flow. Water draining from soil profiles into streams generally has a higher solute concentration than the infiltrating rain water. The uptake of solutes by percolating soil water is not, however, a simple process to model.
