Future snowmelt could have costly consequences on infrastructure

Date:
December 7, 2021
Source:
University of New Hampshire
Summary:
Researchers took a closer look at previous studies with snowmelt
predictions, and because geographical areas respond differently to
climate change, they found future snowmelt incidences could vary
greatly by the late 21st century. Snowmelt could decrease over
the continental U.S. and southern Canada but increase in Alaska
and northern Canada resulting in larger flooding vulnerabilities
and possibly causing major societal and economic consequences
including costly infrastructure failures.



FULL STORY ========================================================================== Climate change and warmer conditions have altered snow-driven extremes
and previous studies predict less and slower snowmelt in the northern
United States and Canada. However, mixed-phase precipitation -- shifting between snow and rain -- is increasing, especially in higher elevations,
making it more challenging to predict future snowmelt, a dominant driver
of severe flooding.

Researchers at the University of New Hampshire took a closer look at
previous studies, and because geographical areas respond differently to
climate change, they found future snowmelt incidence could vary greatly
by the late 21st century. Snowmelt could decrease over the continental
U.S. and southern Canada but increase in Alaska and northern Canada
resulting in larger flooding vulnerabilities and possibly causing major societal and economic consequences including costly infrastructure
failures.


========================================================================== "Estimation of future floods can be a tricky business and yet it is
important information for those planning future infrastructure," said
Jennifer Jacobs, professor of civil and environmental engineering. "For instance, if a region primarily has floods occurring during the winter,
then this work could really help build infrastructure that can handle
those future conditions. And, if the floods are decreasing, then the
design values should also decrease rather than over design." Their study, recently published in the journal Geophysical Research Letters, looked
at previous study predictions of change in snowpack, snowmelt and runoff
with the goal of translating it into information that would be helpful for water resources managers, engineering designers and the general public
living in the areas of Northern California, Pacific Northwest, Alaska
and Canada. The researchers used historical maps and regional climate
model (RCM) simulations that focused on North America. They found that
in the West Coast mountain areas, such as Northern California and the
Pacific Northwest, there could be greater risk of rain-on-snow flooding
because these areas are predicted to warm and produce more rain. This
could increase the melting of any existing snowpack and lead to larger
runoff potential, increasing flooding risk. But this differed in extreme
cold regions like Alaska and northern Canada. Researchers found warmer temperatures in these areas could increase the opportunity for moisture
that could likely lead to more winter precipitation like snow.

"These findings can be important in helping to develop or modify federal
and state governments' long-term policies for climate adaptation," said
Eunsang Cho, a former UNH doctoral student, now postdoctoral researcher at NASA's Goddard Space Flight Center, and lead author of the study. "For
example, the current U.S. government standards for water-related
infrastructure design are based on liquid precipitation data with very
limited guidance on snow or snowmelt information." The researchers point
out that certain infrastructure policies, like the relicensing of dams,
depend on information about extreme weather conditions.

This information can help engineers design infrastructure not based on
past conditions but to anticipate future conditions. In their previous research, Jacobs and Cho created a map that accounts for snowmelt across
the continental U.S. They say this information is already being used by
the state of California in their relicensing process.

This research was funded by NASA's Applied Sciences Water Resources
Program and the U.S. Department of Energy's Office of Biological and Environmental Research program.

========================================================================== Story Source: Materials provided by University_of_New_Hampshire. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Eunsang Cho, Rachel R. McCrary, Jennifer M. Jacobs. Future
Changes in
Snowpack, Snowmelt, and Runoff Potential Extremes Over North
America.

Geophysical Research Letters, 2021; 48 (22) DOI:
10.1029/2021GL094985 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/12/211207174555.htm

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