Contents
How is the sinuosity of a stream calculated?
Channel sinuosity is calculated by dividing the length of the stream channel by the straight line distance between the end points of the selected channel reach. Figure 2. NetMap’s sinuosity tool is located in the ‘Fluvial Morphology Module’.
How is the threshold for a stream channel determined?
Determining a threshold value that represents where a permanent stream or stream channel begins is affected not only by contributing area but also by climate, slope, and soil characteristics. For more information on stream channel initiation, refer to Tarboton and Bras (1991).
How is the geometry of a stream measured?
The measured geometry and sketch map characterize and document the plan form of the stream through the study reach. Sinuosity, belt width, stream meander length, linear wavelength and radius of curvature are measured. Plan-view geometry is best measured with recent, large-scale aerial photographs.
How to find the reach of a stream?
1. Develop familiarity of the designated reach by walking the entire length while looking at the aerial photograph (sometimes it is also helpful to view the reach from a high point). 2. Observe floodplains, terraces, abandoned channels, bedrock outcrops and laterally confining hillslopes or roads.
Where is the highest level of sinuosity found?
Channel sinuosity is an important component of fluvial geomorphology and of aquatic ecology. In general, sinuosity is highest in meandering gravel or sand bedded streams and lowest in confined mountain streams.
Which is the correct scale for Channel sinuosity?
For example, 30 channel widths is the channel segment scale recommended in the Rosgen stream classification system (Rosgen 1996). Channel sinuosity can only be roughly approximated using synthetic streams derived from digital elevation models. Field measurements are required to more accurately define channel sinuosity. Figure 1.
Where does channel sinuosity come from in Rosgen?
Channel sinuosity is also a component of the Rosgen stream classification system (also included within NetMap). However, since channel sinuosity is derived from the routed stream layer built from digital elevation data, it provides only an approximate estimate of the true channel sinuosity.