Briefly explain the common types of erosion that shape a river from source to mouth

The first is Hydraulic Action. This is the force of the river against the banks causing air to be trapped in cracks and crevices. The pressure then weakens the banks and gradually wears it away. Secondly, Abrasion is when rocks carried along by the river wear down the river bed and banks. Thirdly, Attrition is the transporting of rocks by the river smashing against each other, reaking into smaller, smoother and rounder particles. Finally, solution is when soluble particles are dissolved into the river.