To create reversing tidal flow and sediment transport on scale, Maarten Kleinhans built a twenty by three meters flume tilting back and forth every half minute at a small slope. This tilting-principle causes beautiful Waddensea-like basins and estuaries to form in a pilot setup with sand created from a small table with one leg sawed off and replaced by something like a metronome.
Using this immense research instrument, Kleinhans simulates how river mouths are formed. These shallow coastal waters are shaped by the supply of river water and tidal currents and are breeding grounds for shellfish and fish, and so of great ecological value. All the world's major ports are also located in river mouths, so it is crucial that they remain navigable and do not flood.