Chapter 32 - Stream Erosion

Stream power is an important aspect of stream erosion and is determined by a combination of volume and velocity. Stream capacity is the maximum load of sediment that a stream can carry at a given volume of water (discharge). A stream with a large discharge can carry a larger load then a smaller stream. The velocity of water determines the speed in which sediment is transported, and also the size of rock material that can be transported. A faster velocity of water is able to transport larger rocks, while a slower velocity will only be able to transport smaller rocks.The greatest water velocity meanders across the stream channel towards one bank, with the faster velocity being found at the outer banks of the river. Stream erosion is most active at the outside of the river at the outer banks where the velocity is fastest. In this picture of a meandering meandering river the point of most velocity and thus most erosion is at the outside of the river bank above my hand. Overtime the river will expand further out in this direction, broadening the river at this bend.