Network sinuosity

Network sinuosity is a measure of how much the path of the river or stream deviates from a straight line. In general, rivers and streams that are more sinuous generally indicate those that have lower alteration from human disturbance such as channelization and diking, whereas rivers that have been extensively altered tend to be less sinuous. Sinuosity ranges from low (<1.2) to moderate (1.2 - 1.5) to high (>1.5) (Rosgen, 1996).

Low sinuosity

Rivers and streams with lower sinuosity may be more altered by artificial channelization and may have a lower variety of in-stream habitat. Barriers with less sinuous upstream networks may contribute less natural habitat if removed.

High sinuosity

Rivers and streams with high sinuosity are likely less altered by artificial channelization and may have a wider variety of in-stream habitat. Barriers with more sinuous upstream networks may contribute more natural habitat if removed.

Methods:

The sinuosity of each stream is calculated as the ratio between the length of that reach and the straight line distance between the endpoints of that reach. The greater the total length compared to the straight line distance, the higher the sinuosity.
Reaches are combined using a length-weighted average to calculate the overall sinuosity of each functional network.

References:

Rosgen, David L. 1996. Applied river morphology. Pagosa Springs, Colo: Wildland Hydrology.