Use of an imaging infiltrometer to understand soil crack sealing and preferential flow

Abstract:

Soil cracks can act as preferential flowpaths, but their effects on non-equilibrium flow and transport are difficult to quantify because of dynamic interactions between water and the crack structure. I have developed a simple method that combines infiltration measurements with digital imaging to simultaneously quantify infiltration and crack closure. Preliminary data collected on soils with moderate shrink-swell potential (possessing surface-connected cracks of 1-5 mm width) reveal that soil cracks begin to close almost immediately after the onset of infiltration, but soon thereafter attain quasi-stable geometries. This suggests that in the context of short-term infiltration tests it may be possible to model soil cracks as having relatively constant contributions to preferential flow.