The riverbeds

The channel bottom of a river is called bed. The flow rate (amount of water that passes a point in a given time) vary throughout the year. The minor riverbed is the physical confine of the normal water flow. The moderate bed corresponds to the non-overflowing floods, contained by the higher river banks. The major bed is the rise in water level overflowing its banks and flowing onto its flood plain. Preserving these beds is essential to slow down the water in order to protect the urban areas against flooding.