4 types of water erosion :
1) Hydraulic Action - Force of the water on the bed and banks of the river. It's particularly powerful when the river is in flood. The force of the water removes material from the bed and banks.
2) Solution - Some rock minerals, such as calcium carbonate in limestone and chalk, slowly dissolve in river water, which is sometimes slightly acidic.
3a) Abrasion - The river carries with it particles of sand and silt and moves pebbles and boulders at times of high flow. This material rubs against the bed and banks of the river and wears them away.
3b) Attrition - The load being carried by the river collides and rubs against itself, breaking up into smaller and smaller…