Partially to fully saturated flow through smooth, clean, open fractures: qualitative experimental studies

B. R Jones, L.B Brouwers and M.A Dippenaar 2018.

Hydrogeology Journal.

Fractures are both rough and irregular but can be expressed by a simple model concept of two smooth parallel plates and the associated cubic law governing discharge through saturated fractures. However, in natural conditions and in the intermediate vadose zone, these assumptions are likely violated. This paper presents a qualitative experimental study investigating the cubic law under variable saturation in initially dry free-draining discrete fractures



Groundwater flow


saturated flow and    


In vertical fractures, preferential flow occupies the minority of cross-sectional area despite the water supply. Movement of water through the fractured vadose zone therefore becomes a matter of the continuity principle, whereby water should theoretically be transported downward at significantly higher flow rates given the very low degree of water saturation.

Key Words: 

Variable saturation, Unsaturated zone, Fracture flow, Cubic law, Laboratory experiments/measurements .