The Functioning Coho Winter Habitat ranks 6th fields
on the basis of the following factors (as requested by
the MidCoast Watersheds Council): length of
potential
habitat (low-gradient unconfined stream reaches flowing
through hydric soils -- "
unconfined"
as described in the DEM analysis);
large
woody debris frequency (AHI);
percent pools (AHI);
channel
widths per pool (AHI); and
length
of side channels (AHI). All factors were combined
to form a final ranking for each 6th field. All factors
were weighted equally. A high value for each factor increased
the ranking, except for channel widths per pool, where
a high value reduced the ranking. We used a ranking method
that prevented bias due to protocol differences between
different data sources.
The highest possible ranking
is 1 (best- functioning habitat by these criteria); the
lowest possible ranking is 100 (lowest-functioning habitat
by these criteria).
For details on the methods used to develop the 6th field
rankings, see coho_winter_methods.doc. This analysis incorporates
data from AHI surveys, from NRCS soil surveys, and from
DEM analysis. Sixth fields lacking AHI data could not
be ranked in this analysis.
The rankings can help prioritize 6th
fields for actions designed to improve coho winter habitat,
such as creation of off-channel habitat and placement of
large woody debris. The rankings should not be used alone
for this purpose, but should be used in conjunction with
other data, particularly field verification of suitable
conditions.
Before using the rankings, we recommend
careful review of the detailed methods for each individual
analysis that entered into the multi-factor analysis (link
to full report, not just web methods). All datasets have
their limitations and proper uses, and many of these are
discussed in the assessment report.
Please address questions or comments
to:
Dr. Ralph Garono
Principal Investigator
Earth Design Consultants, Inc.
rgarono@earthdesign.com
Laura Brophy
Principal Investigator
Green Point Consulting
brophyl@peak.org |
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