(The Center Square) – Outside of providing a space for winter activities like sledding and skiing, a heavy snowpack provides water for many purposes, like drinking and irrigation, during the dry months.
Oregon State University College of Engineering researchers developed a more holistic calculation technique to figure out how much water these snowpacks hold and for how long, according to the school.
“Water managers tend to consider a portfolio of infrastructure options – surface water reservoirs, groundwater recharge programs, etc. – to match supply to demand,” OSU’s David Hill, the study’s lead author and a professor of civil engineering at the school, said in a release. “Increased understanding of how much water is in snow should allow them to make long-term planning decisions for how to adjust that portfolio.”
Along with doctoral student Christina Aragon, Hill examined nearly 40 years of snowpack data. They found a 22% drop in how much water is held annually in the mountain snowpacks in the continental United States.
“Unlike other widely used metrics that capture snow variables at a single point in time, like maximum snow water equivalent, or describe snow characteristics in terms of time, such as length of snow season, snow water storage is applicable at numerous time and space scales,” Hill said. “It’s really just a cumulative sum, not a maximum value; it’s like adding up the number of miles you drive in a given year rather than just thinking about the 500 you did on one day for your road trip.”
The researchers note that 72% of this snow is in the mountains, despite mountains covering just 16% of the land area.
“There are many ways to describe or quantify our snow resources, but some of the traditional measures, such as the April 1st snowpack, increasingly do not tell the full story,” Hill said. “We present a new way of describing snow’s water storage ability that adds deeper understanding and has more applicability in cases where our snowfall is increasingly intermittent or, regrettably, turning to rain.”
The research, published in Hydrology and Earth System Sciences, expands on a measuring technique called snow water equivalent. It measures how much water is left in a container once the snow that was in it melts. The research was supported with the taxpayer-funded resources of the university, but not any outside grants.
“By considering the amount of water held in the snowpack and the amount of time the water is stored as snow, we are able to quantify water storage in different types of snowpacks,” Aragon said. “This includes persistent snowpacks, like we typically have at high elevations in the mountains; transient snowpacks, which are typically found at lower elevations; and snowpacks that are transitioning from persistent to transient due to climate warming.”
