Parts of Colorado, Wyoming and Utah are drying out due to climate-driven changes in stream flows, and these states will shift to become more like the most arid states of the Southwest, federal researchers found in a scientific study published last week.
The lead author of the study said Colorado will experience a 50 percent to 60 percent reduction in snow by 2080.
“We’re not saying Colorado is going to become a desert. But we see increased aridity moving forward,” said hydrologist Katrina Bennett at the federal government’s Los Alamos National Laboratory in New Mexico.
The researchers used an artificial intelligence “machine learning” system that allowed them to analyze massive amounts of data collected over 30 years including soil moisture, volumes of water in streams, evapotranspiration rates, temperature and precipitation across the varying landscapes within the Colorado River Basin. Tracking the West’s hydrology on such a scale previously would have taken years.
They concluded that large losses of snow will transform high-elevation areas and that the phenomenon of melting snow that creates water will disappear entirely in some areas as temperatures rise.
The study was published, following peer review, in the journal Earth and Space Science and distributed Thursday by officials at the National Oceanic and Atmospheric Administration.
For Colorado and surrounding “upper basin” states, the scientists projected wide shrinking of snow, leading to less spring snow melting followed by decreasing water in streams, especially in the Rocky Mountains. The study predicted, in particular, markedly increased aridity along the Green River as it flows near the borders of Colorado, Utah and Wyoming.
“In some parts of Colorado, we will see a higher-elevation preservation of snowpack, because it is so high,” Bennett said, citing the mountains above Leadville in central-western Colorado.
“But other areas like the San Juan Mountains were seen to be losing snowpack significantly,” she said.
The unsupervised machine-learning system greatly accelerates analysis of weather and hydrology data, giving a robust new way of incorporating vast data to anticipate changes and track trends. Bennett said she and her colleagues plan to apply their system to analyze the drought-prone Rio Grande River Basin covering southern Colorado, New Mexico and Texas.
The Colorado River Basin encompasses a seven-state area from sea level at the Gulf of California to mountain peaks higher than 14,000 feet in Colorado. Water in the basin supplies food growers, including those who produce a large portion of the nation’s fruits and vegetables. Expanding cities — including Albuquerque, Denver, Colorado Springs, Los Angeles, Salt Lake City, San Diego and Santa Fe — rely on water diverted from the river and its tributaries to survive.