Exner equation

The Exner equation describes how the shape of a riverbed or seabed changes over time due to sediment movement. It relates the change in bed elevation to the balance between sediment being added or removed and the flow of water. When water transports more sediment than it deposits, the bed erodes; when it deposits more than it erodes, the bed builds up. Mathematically, it links sediment flux (movement) to changes in bed elevation, helping us understand and predict river or coastal landscape evolution under different flow and sediment conditions.