Question

Why do floods deteriorate rivers sides? Widen over time? Dirt sides for reference

Answer 1

Works in a river or stream are no different ... flood are not contained by the dominant channel. ..... after some time (possibly many years).

Answer 2

The term is called erosion.Erosion occurs when water or wind deteriorates dirt,rock, basically anything as long as there is constant friction which will eventually break down such as the dirt sides of a river.