Types Of Erosion

- Abrasion:  Occurs when the load the river is carrying repeatedly hits the river bed and banks, causing some of the material to break off.   - Attrition:  When the stones and boulders carried by the river knock against each other and over time are weakened, causing bits to fall off and reduce in size.   - Solution/ Corrosion:  Only occurs when the river flows over certain types of rock, such as chalk and limestone. These are soluble in rainwater and become part of the water as they are dissolved by it.   - Hydraulic Action:  The sheer force of the water hitting the bed and the banks. This is the most effective when the water is moving fast and there is a lot of it.