How to conduct variable-density sand tank experiments: practical hints and tips

Abstract

Sand tank experiments are a powerful tool for the investigation and visualization of groundwater flow dynamics. Especially when studying coastal aquifers, where the presence of both fresh and saline water induces complex variable-density flow and transport processes, the controlled laboratory settings of tank experiments help scientists to identify general patterns and features. This technical note provides practical information on planning, conducting and evaluating sand tank experiments, with a focus on application to coastal hydrogeology. Materials, e.g. the sand tank itself, liquids and porous media, are discussed, as well as their handling and auxiliary equipment. The collation of hints and tips is intended to guide novices, as well as experienced researchers, and possibly prevent them from repeating the errors that have been encountered during a long history of experimental work conducted by the authors and researchers associated with many other published studies.

Visualizing the ‘iron curtain’ formation in the subterranean estuary using sand tank experiments

“…To fully understand the effect of the iron-curtain on solute exchange at the land sea transition zone, comprehensive investigations on redox-processes-and associated secondary reactions are required. As field sites are often difficult to access, the replica of a beach aquifer under laboratory conditions can aid to better understand the fundamentals of the involved physical and biogeochemical processes (Stoeckl & Houben, 2023). For instance, Röper et al (2014), Shen et al (2015), Zhang et al (2017) or Delwar et al (2024) mimicked coastal aquifers in laboratory experiments and found the freshwater-seawater interface in the STE to be far less stable than previously thought.…”

Experimental Study on Seawater Intrusion Law and Countermeasures within Island Underground Water-Sealed Oil Storage Caverns

“…Physical model tests have become one of the effective methods for studying seawater intrusion. Sand tank experiments are a powerful tool for the investigation and visualization of seawater intrusion, which can help researchers to identify general patterns and features [38]. Numerous experimental studies on seawater intrusion have been conducted by scholars [39][40][41].…”