Coupling Surface Water and Groundwater Flows in a Laboratory Model Using Foam as Artificial Groundwater Material

A laboratory mock-up of a surface water groundwater system with foam blocks used to replicate a groundwater material was mounted in a tidal basin in the Hydraulics Laboratory at Cardiff University, UK. River flow in the form of a channel was generated, with an oscillating weir at the lower boundary of the system producing tides or controlled water levels. The purpose of the experiment was to investigate the manner in which flow and a conservative tracer interacted between surface and sub-surface flows for simulated riverine and tidal conditions. In these controlled laboratory conditions, results obtained with respect to flows were consistent with the laws governing surface-subsurface flows. In contrast, the conservative tracer could not move through the foam for any meaningful results to be obtained, which was thought to be due to the dominance of surface tension and sorption in the foam pores.