Oxbow lake

• Oxbow lakes are formed from meanders. The river starts to flow from side to side in a helicoidal flow, moving materials across the river channel. With the river flowing fastest on the outside bend increasing the erosive power and flowing slowest on the inside bend leading to deposition.
• The fastest flowing water erodes the outside bends using hydaulic action, when the shear force of the water gets into small cracks, and breaks down the rock.
• Abrasion also occurs, this is when the river banks are eroded by the rocks hitting against them.
• Overtime, continual erosion and deposition narrows the neck of the meander. Often during a flood, the river will cut through the neck of the meander. The fastest current will now be flowing in the centre of the river chanel as the river continues on this straight path.
• The meander is abandoned as new deposition beside the slower banks seals off the ends and the cut-off becomes an oxbow lake that will eventually dry up.