ABSTRACT
A water droplet incident at the soil surface has just two options: it can infiltrate the soil or it can run off. This partitioning process is critical. Infiltration, and its complement runoff, are of interest to hydrologists who study runoff generation, river flow, and groundwater recharge. The entry of water through the surface concerns soil scientists, for infiltration replenishes the soil’s store of water. The partitioning process is critically dependent of the physical state of the surface. Furthermore, infiltrating water acts as the vehicle for both nutrients and chemical contaminants.
