Water Infiltration Control: a Channel System Concept

Abstract

AbstractA channel system concept of infiltration was developed to describe the profound influence of large soil pores on the movement of soil water and air. This concept hypothesizes that soil surface conditions or channel system states control the flow of water and air in subsurface networks of large pores. Six channel system states (A through F), representing common soil surface conditions, form the basis for controlling infiltration within a range often exceeding one order of magnitude. Channel system states A, B and C represent rough surfaces with open, constricted and closed channel ports, respectively; whereas states D, E and F represent smooth surfaces with open, constricted and closed channel ports. Infiltration rates usually vary in the order A>B≃D>C≃E>F. Under state A the soil surface and subsurface channels are hydraulically and pneumatically connected, and under state F they are disconnected. Under state A water penetration rates are rapid and flow routes are relatively direct, whereas under state F rates are slow and routes are extremely tortuous. Soil surface management can be directed to achieving the desired channel system state and hence the design level of infiltration. The channel system concept appears applicable to a wide range of infiltration‐related problems.