The Helley-Smith system was originally developed by the United States Geological Survey (USGS) to collect samples of displaced sediment 10-15 mm above the base of the bed in waterways. It comes in a variety of sizes and shapes.
The displacement of materials is closely related to water flow. The greater the water flow, the more capable the river is of transporting increasingly large objects.
This device can be used to determine the amount of carried materials based on water flow and to characterize the type and granularity of the transported objects.
Ultimately, such a measurement is highly valuable for several reasons:
It makes it possible to define the rate at which dams can fill and thus improve the ecological continuity of water flows by allowing sediments to be sifted at the right times.
It also provides support for other tools in the understanding of phenomena involving the morphological change of riverbeds (incisions, meandering, braiding, changes in flow lines, and impacts on ecological environments, materials, and humans)