- 6. Reach conditions: Note the general conditions of the
reach. Be sure to note factors such as recent flood history, beaver
activity, and weather conditions. Also record stage height and the method
for determining stage height.
- 7. Reference location: Provide a general description of the reference location
(for example, "gage on left bank just below Highway No. 1462 bridge").
The reference location should be a permanent structure such as a USGS gage
or a bridge . When a permanent structure is not present, a semipermanent
marker (such as an iron pipe) is installed at a site. The reference
location serves as a classification variable, providing a geographic
marker linking habitat data collected at the reach level with data
collected at other levels of the spatial hierarchy. Record the latitude
and longitude of the reference location. Also check if a photograph of
the reference location is made. If a bridge is present, additional
photographs, facing upstream of and downstream from the center of the
bridge, further serve to document the reach.
- 8. Reach boundary nearest to reference location: Note whether the reach
boundary nearest to the reference location is upstream of or downstream
from the reference location. Using a tape measure or rangefinder, record
the distance from the reach boundary to the reference location. In
addition, record whether the semipermanent boundary marker is located on
the left or right bank (looking downstream) at this reach boundary and
provide a brief description of the boundary marker (for example, "iron
bar, painted orange, about 2 m from the wetted channel").
- 9. Channel width at reach boundary: Channel width is the
horizontal distance measured from left edge of water to right edge of
water along the existing water surface. To provide consistency in
measurement, protruding logs, boulders, stumps, or debris surrounded by
water are included in the measurement of the water surface. Islands are
not included in the measurement. Any solid accumulation of
inorganic sediment particles protruding above the
water and supporting woody vegetation is considered an island. Measure
the channel width and multiply times 20.
- 10. Geomorphic channel units: Record all geomorphic channel units that
are greater than 50 percent of the channel width, and the length of each.
These data provide information on spatial dominance and diversity of
geomorphic channel units. Use additional space as needed.
- 11. Reach length: Record the reach length. In addition,
indicate where the semi-permanent boundary marker at the boundary furthest
from the reference location is located, and record a general description
of the boundary marker.
- 12. Stream type: Record the stream type represented by the reach. Stream type relates to
the character of a channel, which may be straight, meandering, braided,
channelized, or pool and riffle (Leopold and Wolman, 1957). Leopold and
Wolman (1957) recognized that stream types are not distinct, but
represent a continuum of channel configurations which are a function of
flow, the quantity and character of the sediment, and the composition of
bed and bank material. Therefore, stream type conveys information
regarding channel form, processes, and geomorphic channel
units.