Mapping snowpack from the skies brings new precision to water forecasting
As climate change shifts the norms of water management, a company is mapping the West to collect more accurate snow depth data.
Airborne Snow Observatories flies planes over watersheds and beams hundreds of thousands of laser pulses each second to the snowpack below using a laser scanner or airborne lidar system. They’re creating elevation maps that aid in calculating snow depth and the water supply forecast across the West.
As the Associated Press reported, the company, a spinoff from NASA’s Jet Propulsion Laboratory, recently mapped the headwaters of the Colorado River for the first time.
ASO co-founder Jeffrey Deems says by comparing these maps to ones done in the summer, they can calculate the snow’s depth throughout the whole watershed, bringing more precision and scope to water forecasting and management.
“What can you do when you have higher confidence in your snow inventory and therefore your water supply forecast?” Deems said of the possibilities. “Can you start to make more informed decisions earlier in the year? Do you get early warning of floods or droughts within the year that can improve decision making come snowmelt season?”
Conventional methods used by the federal Natural Resources Conservation Service monitor snowpack via SNOTEL stations. A mountain watershed in Colorado could have several of these stations that continuously monitor snowpack weight and estimate the amount of water available when snowpack melts.
But this method, Deems says, relies on comparisons to past data and can be less dependable as climate change alters snow accumulation and melt patterns.
“What we’re doing is mapping the snowpack everywhere," Deems said. "It gives us an accurate snow volume and therefore decouples us from that reliance on the historic record.”
He says with aerial snow mapping they can get “very accurate” depths every three meters throughout the whole watershed, and since their clients have all been public entities the data is accessible to the public on the ASO's website.
It's expensive, Deems says, but inaccurate and geographically limited data also has its costs.
“If we have less confidence in our runoff forecasts that impacts the distribution of water rights, the availability of water in early and late seasons for farmers and ranchers, and municipalities,” Deems said.
Deems says they’re learning more about the dynamics of snow accumulation and runoff – what he calls the “basin plumbing.”
In the Mountain West, the company's hoping to expand its mapping into New Mexico, Wyoming and Arizona.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, the O'Connor Center for the Rocky Mountain West in Montana, KUNC in Colorado, KUNM in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.