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.