Explain how river meanders may change over time [4 marks]

A meander is a winding curve or bend in the river. The river erodes fastest on the outside bend of the river through a process called lateral erosion. Lateral erosion results in undercutting of the river bank and consequently forms a steep sided river cliff. One method of lateral erosion is hydraulic action, where the sheer force of the water smashes against the river bank causing it to erode.However, the river changes over time also due to deposition. On the inside of the bend, where the river is slower, material gets deposited due to increased friction. This results in the formation of a slip-off-slope on the inside bend of the river.Over time, rivers change shape due to both erosion and deposition, causing the river to change shape and slowly migrate downstream.