watervulnerability

Coconino National Forest Watershed Vulnerability Assessment, Southwest Region (R3)
Annual 22.5 22.8 0.4 23.4 0.9
Table 4. Modeled precipitation (inches) and predicted changes from historic, by month for the Coconino
NF analysis area
The team also considered modeling conducted by Rajagupal (Rajagupal et al. 2010) in his assessment of
hydrologic change in the Black and Verde Rivers. This analysis included the entire WVA area, with the
exception of the Upper Clear Creek (East Clear Creek) watershed. The selection of these models was
based on a “best fit” comparison of all available models with historic temperature and precipitation
records that was completed by Dominguez et al. (2009). Some of their results are displayed in Figure 16,
and show a fairly substantial decrease in spring runoff for all future projections, with a slight increase in
fall flows.
Figure 16. Simulated annual hydrograph for the Salt and Verde Rivers, based on VIC modeling. Periods1:2009-
2038; 2:2039-2068; and 3:2069-2098.
Hydrologic Changes of Concern
The Forest team considered the potential changes as indicated by the CIG and Rajagupal modeling, and
considered how these potential changes might impact the selected aquatic resources. The following is a
brief summary of those considerations for each water resource value.
Herpetiles
• Less spring precipitation and runoff could result in drying of springs wetland habitats such that
habitats might not persist through the summer, resulting in reduced populations or loss of species.
• Dispersal might be improved in fall (more water).
Warm Water Species
• Natives spawn in spring triggered by snowmelt hydrograph, spawning success may be reduced.
145 Assessing the Vulnerability of Watersheds to Climate Change