Dust abatement could be part of a climate adaptation strategy in the Upper Colorado River Basin
By Summit Voice
SUMMIT COUNTY — Even before a series of intense dust storms coated the Rocky Mountain snowpack in 2009 and 2010, scientists had calculated that the dust speeds the spring meltdown and reduces runoff in the Colorado River Basin by as much as 5 percent, based on data gathered between 2005 and 2008.
Dust storms in subsequent years saw unprecedented levels of dust loading, on the order of five times the 2005–2008 loading, a team of researchers wrote recently in a paper published for online discussion in the journal Hydrology and Earth System Sciences.
In related research, University of Colorado, Boulder scientists also recently published findings showing that dust deposition around the West has increased exponentially in the past couple of decades, based on measurements compiled from the National Atmospheric Deposition Program. Read more in this Summit Voice story.
The research on dust-on-snow events has significant implications for water management in the West, along with raising public health concerns that aren’t on the radar screen of East Coast-based policy makers, according to CU-Boulder professor Jason Neff.
The latest study found that “extreme” dust event absorbs two to four times the solar radiation, and shifts peak snowmelt an additional three weeks earlier, to a total of six weeks earlier than pre-disturbance.
The numbers suggest that dust-abatement should be seriously considered as a potential component of any climate adaptation strategies in the Upper Colorado River Basin.
The Colorado River provides water to 40 million people in seven states and two countries and to 5.5 million irrigated acres. Climate models project runoff losses between 5 to 20 percent from the basin by mid-21st century due to human-induced climate change.
Water is lost when the snow melts earlier because evapotranspiration increases. By some estimates, the earlier exposure of soils and germination of plants decrease annual runoff by more than 1 billion cubic meters, about 5 percent of the annual average snow.