Hjulström Curve

The Hjulström Curve illustrates how particles in a river or stream behave based on water flow speed and particle size. It shows that small particles like silt and clay are carried away at lower speeds, while larger particles like sand and gravel require faster flows to be eroded or moved. When flow is slow, particles settle and deposit; at moderate speeds, erosion occurs; and at high speeds, particles are transported or carried downstream. This helps explain how rivers shape their channels by eroding, transporting, or depositing materials depending on flow velocity and particle size.