The line connecting the deepest parts of a channel is known as the thalweg. Water does not flow in a straight line. Even in channels that appear to be straight, the thalweg will be shifting from side to side, which will ultimately create an alternating series of bars. Straight stretches often contain alternate bars formed by material deposited on the channel bed along the sides alternating down the channel. Deep pools are formed opposite of the alternate bars, and the shallow riffles are found midway between. Meanders serve to lengthen the channel, dissipating the stream s energy over longer distances than would a straight channel, which results in a more stable stream. The distance along the centerline of a channel ( channel length) divided by the distance between meanders is used as a measure of stream sinuosity. One effect of meandering is to increase resistance and with it energy dissipation at the pools, making the grade line more uniform; thus meandering serves to help the stream reach a condition of near equilibrium. It should be noted that meandering is synonymous with bank erosion.

Sinuosity refers to the classification of streams by their pattern. There are three types of stream patterns: sinuous, braided, and meandering. However, it should be noted that these are relative patterns, and there is no bright-line distinction between them. Streams with a channel versus valley length of less than 1.5 are considered to be sinuous, those with 1.5 or greater are considered to...