Channel type information, which was not available for
the entire study area, was provided by USFS for portions
of the study area in the
densified
streams layer. In order to develop a study area wide
stream channel type layer, we queried the DEM-derived
stream gradient
and
stream confinement
layers. This resulted in a very detailed stream channel
type layer that is limited by the quality of the
10
m DEM and the computer models.
Because DEM-derived stream gradients were originally
calculated in degrees our conversion to slopes were rounded.
The following categories were defined:
| Slope (%) |
Confined |
Unconfined |
| 0 |
|
EL, ES, FP1 |
| <=1.75 |
LC |
FP2-3 |
| 3.5 |
MC |
MM |
| 5.25-8.75 |
MV |
MV-U |
| 10.51-14.1 |
SV |
SV-U |
| > 14.1 |
VH |
VH-U |
We found that we had to create several new categories (Unconfined
for MV, SV, and VH). We used the computer to classify all
categories with slopes > 0 and we hand coded the EL,
ES and FP1 stream channel types.
Stream channel types can be used to
locate areas that are potentially important fish bearing
areas and important areas for material / sediment transport.
This layer was created as a first approximation
of stream channel types and should be modified or replaced
as ground-truthed data become available. Several new stream
channel types were created as a result of the computer modeling.
With the exception of the MV-unconfined, the other channel
types represent a small proportion of the total stream length
and may represent biologically significant areas such as
stream confluences or impoundments.
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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