V-shaped valley

• Rivers begin high up in the mountains, in the upper course of the river, with steep sided valleys
• The river cuts a deep notch down into the landscape using hydraulic action. Hydraulic action is when air is compresses into the riverbank causing material to be dislodged
• Abrasion also occurs, this is when the force of the water throws bedload against the banks causing erosion
• In this way the river is eroded vertically.
• As the river erodes downwards, the sides of the valley are affected by rain and gravity, causing more material to collect in the river. The material is the used to further erode the river bed.
• The valley bottom is usually narrow and filled mainly by the chanel