River Erosion is the river erodes away the bed and banks of its channel vertically and laterally.
Vertical erosion is the downward erosion which deepens the river channel
Lateral erosion is sideward erosion which widens the river channel
There are four ways how the river erode the bed and the bank( EROSIONAL PROCESS)
1. Hydraulic action– the force of river flow helps to break the rock and dragging them away from the bed and the banks of the river.
2. Corrasion/abrasion– the grinding of the rock fragments carried by the river against the banks and bed of the channel. This grinding action will widens and deepens the channel.
3. Attrition– the knocking of rock fragments in the water against each other. The fragments are broken into smaller and become smoother pebbles.
4. Solution/corrosion– the process of the water reacts chemically with soluble minerals in the rocks and dissolve them.