How Colorado’s Water History Shapes Snow Science


Impacts of climate change on the snowpack

“During the 80 to 90 year period of snow courses, these watersheds have changed,” Fassnacht said. “There has been a land use conversion, fires, insect infestations and a lot of disturbance in the forest. Climate change is making conditions different – ​​the system is getting warmer and trees are growing at higher altitudes.

According to Fassnacht, as western climates become more varied and unpredictable, so will the structure of snow. Heavy snowfalls superimposed on melting snow banks will create more variations between snow layers, which will create unstable snow. Greater temperature variations between October and February create more fluctuations in the snowpack and weaken the stability of the lower layer, which can trigger more avalanches.

Additionally, the lower basin downstream of Lake Powell has experienced an unprecedented drought in the past 20 years that has changed the way California, Arizona, Nevada, and New Mexico use water.

In fact, the Colorado River no longer reaches the Pacific, but is instead reduced to a scorched delta dotted with skeletal capillaries that murmur the river’s once mighty current. The Upper Basin above Lake Powell, however, did not see the same reduction in overall snowpack, although snow distribution changed.

“We all want to be able to get the sound, tweet the simple response, but we’ve seen over the past few years that things are complex,” Fassnacht said. “In northern Colorado, stations at lower elevations actually get more snow, and higher stations get less snow. It doesn’t correspond to things getting warm everywhere, because then lower elevations would have more rain than snow. »


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