The document describes how a river meander evolves over time through erosion and deposition, eventually cutting off to form an ox-bow lake. As the meander erodes the outside of bends and deposits sediment inside bends, its course changes shape until the neck of the meander is narrowed by erosion and cut through during a flood, allowing the river to flow in a new course and abandoning the old meander, which then seals off to form an ox-bow lake.