Future snow? A spatial-probabilistic assessment of the extraordinarily low snowpacks of 2014 and 2015 in the Oregon Cascades
Other literature type
Sproles, Eric A.
Roth, Travis R.
Nolin, Anne W.
(issn: 1994-0424, eissn: 1994-0424)
In the Pacific Northwest, USA, the extraordinarily low snowpacks of winters
2013–2014 and 2014–2015 stressed regional water resources and the
social-environmental system. We introduce two new approaches to better
understand how seasonal snow water storage during these two winters would
compare to snow water storage under warmer climate conditions. The first
approach calculates a spatial-probabilistic metric representing the
likelihood that the snow water storage of 2013–2014 and 2014–2015 would
occur under +2 °C perturbed climate conditions. We computed snow
water storage (basin-wide and across elevations) and the ratio of snow water
equivalent to cumulative precipitation (across elevations) for the McKenzie
River basin (3041 km<sup>2</sup>), a major tributary to the Willamette River in
Oregon, USA. We applied these computations to calculate the occurrence
probability for similarly low snow water storage under climate warming.
Results suggest that, relative to +2 °C conditions, basin-wide
snow water storage during winter 2013–2014 would be above average, while
that of winter 2014–2015 would be far below average. Snow water storage on
1 April corresponds to a 42 % (2013–2014) and 92 % (2014–2015)
probability of being met or exceeded in any given year. The second approach
introduces the concept of snow analogs to improve the anticipatory capacity
of climate change impacts on snow-derived water resources. The use of a
spatial-probabilistic approach and snow analogs provide new methods of
assessing basin-wide snow water storage in a non-stationary climate and are
readily applicable in other snow-dominated watersheds.