This GIS summary is another example of a multifactor
analysis. In this summary, we located areas where
soils
at high risk of erosion lie upon areas that may be prone
to
shallow landslides.
These are areas that can potentially contribute coarse
and fine sediments to stream networks.
We used ARCView to intersect the soils layer with the
results of the landslide analysis. Due to the size of
these files (> 500 MB each), we processed each major
river drainage separately. Results for each 6th field
are grouped by major river drainage in the spreadsheet
version of the data (right) and proportion of high risk
landslide areas (SMORPH) covered by soils with 'severe',
'moderate', and 'slight' erosion risks have been merged
with the 6th field watershed basin coverage (right).
The graphic (right) ranks each 6th Field Watershed on
the basis the proportion of watershed area that meets
the two criteria, i.e., 10 X 10 m cells that have both
soils with a '
severe' erosion risk and that are
prone to shallow landslides. The actual data layers used
to construct this summary are too large to distribute
on the web site: they are available from the MCWC office.
The 6th Field Watershed Rank can be
used to identify 6th fields where soil units prone to erosion
are located on areas susceptible to shallow landsliding
(potential sediment delivery). The detailed GIS layers (available
from the MCWC office) can be used for land use planning,
e.g., to stabilize areas that may be chronic sediment source
areas.
Please note that the results from the
Landslide Model have not been validated. Therefore, this
analysis may be refined once the model is improved.
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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