Erosion of sediments, occurs where capacity exceeds load. Nickpoints gradually eroded upstream, by combination of basal sapping and mass wasting of caprock. Lower in drainage basin lateral erosion and valley widening as meandering stream channel migrates back and forth across the floodplain. Transport of sediments Deposition of sediments, where load exceeds capacity. In headwaters, load often exceeds capacity where lots of sediment is delivered to channels, like from glacial meltwaters or mass wasting.
Result is braided channel.
Floodplains - broad, flat valley bottoms adjacent to a stream channel. A. Floodplains are formed by a combination of lateral erosion and deposition of sediments during floods. B. Meandering stream channels migrate with time, because velocity varies across the channel. This asymmetrical work across the channel causes meandering streams to migrate laterally across the floodplain and down valley. As a meander bend erodes the channel down valley, it can actually cut off another meander.