watervulnerability

The sensitivity evaluation typically resulted in maps
showing relative sensitivities of subwatersheds. Two
examples of this type of product are displayed. Figure 15
shows the sensitivity rating from the Umatilla NF, where
(like the GMUG example) a matrix was used to produce
a combined rating of intrinsic and anthropogenic
factors. A combined sensitivity rating was applied
to a composite of resource values. The Coconino NF
developed different sensitivity ratings for each water
resource issue (Figure 16).
Recent trends and projected future trends in resource
conditions should also be included. For example,
increased water diversion could exacerbate effects on
a resource, whereas anticipated road improvements
could improve condition and reduce effects that might
otherwise occur.
EVALUATE AND CATEGORIZE
VULNERABILITY
Climate change is a risk-multiplier… any decline
N
NF Boundary
HUC6
WI Counties
Low
Moderate
High
Very High
1:1,000,000
Figure 10. Relative vulnerability of wetlands to climate change for HUC6
watersheds on the Chequamegon-Nicolet National Forest.
Figure 17. Classification of climate-change risk to wetlands
on the Chequamegon-Nicolet NFs. The rating is based on
the proportion of total wetland and acid wetland within the
National Forest boundary in each HUC-6. Total wetland area
ranged from 0 percent to 55.8 percent of the area for all HUC-
6 watersheds. The HUC-6s with less than 10 percent were
rated “low,” those with 10 percent to 30 percent were rated
“moderate,” and those with greater than 30 percent were rated
“high.” The HUC-6s with less than 5 percent acid wetland area
were rated “low,” those with 5 percent to 15 percent were rated
“moderate,” and those with greater than 15 percent were rated
“high,” and above that value were "very high". These two risk
classes were combined to form one vulnerability classification
for each watershed.
18 | ASSESSING THE VULNERABILITY OF WATERSHEDS TO CLIMATE CHANGE
in the ecological resilience of one resource
base or ecosystem increases the fragility of
the whole —HRH Charles, The Prince of Wales,
addressing UN climate conference COP15,
Copenhagen (December 2009)
A relative rating of vulnerability of water resources to
climate change was produced by combining information
from the evaluation of resource values, exposure, and
sensitivity. Pilot Forests used a variety of approaches
to complete this step. Primary determinants were the
number of water resources selected for analysis, and
the way values, sensitivities, and responses had been
described. Some pilot Forests classified vulnerability
based on a threshold or ecological value (such as the
amount of wetland area in each watershed, as shown in the
Chequamegon-Nicolet example in Figure 17). The most
common approach used by pilot Forests was to merge the
location of values with ratings of watershed sensitivity,
and then overlay that summary rating with differences
Composite Aquatic Resource
Coconino National Forest WVA
High Value, Sensitivity and Exposure
High Value and Sensitivity, Moderate Exposure
High Value, Moderate Sensitivity and High Exposure
Figure 18. Vulnerability ratings from the Coconino NF.
The map displays the subwatersheds with the highest
density of water resource values (native fishes, amphi bians,
water uses, stream habitat, riparian and spring habitat, and
infrastructure) that also have high or moderate sensitivity
and high or moderate exposure.