Meander

• Meanders form when rivers move around in pools and riffles which lead to changes in the speed and depth in a river channel.
• Pools are areas of slower, deeper water filled with fine sediments, where as riffels are shallower and greater turbulance, found around larger stones.
• Hydraulic action takes place, this is when air is compressed into the riverbank cousing materials to be dislodged.
• The dislodged materials fall and swirl around through the process of abrasion when the force of the water throws bedload against the banks of the river, causing erosion.
• The river starts to flow from side to side, in a helicoidal flow, moving material across the river chanel. With the river flowing fastest on the outside bend increasing the erosive power and flowing slowest on the inside bend leading to deposition.
• This leads to river cliffs and beaches developing. Meanders migrate downstream as erosion continues.