Aerial snow measurement could help Calif. ag
Frank Gehrke, chief of snow surveys for the California Department of Water Resources, could have done his last trek into snow covered mountains to measure snowpack if aerial snowpack surveys prove to consistently do a better job of estimating the volume of water that will come from mountain snow and when it will arrive in lower California elevations.
With snow samples, historical data and use of mathematical formulas, Gehrke and predecessors plus other department officials have been the ones to break the bad news, more often than not recently, about the volume of water that will have to be shared by farmers, hydroelectric power plant and the general public for the summer months.
Lenny Bernstein, reporter for the Washington Post wrote that about 150 people are usually involved in taking snow samples in the state, using satellite images and data from sensors buried in the ground to predict the water supply for California. The problem is that these predictions are off by around 18 percent at least half the time.
Being off in predicting means wasted water, lost potential use of water or shortages of water that are unforeseen.
Trying to eliminate this error in predicting and streamlining the whole process is a new experiment in snowpack measurement. “For the past few weeks, researchers from NASA and the California Institute of Technology’s Jet Propulsion Laboratory have been flying over the Tuolumne River Valley, which runs through Yosemite National Park, with sophisticated instruments that measure the snow’s depth and area, as well as the amount of energy it absorbs from the sun,” reported Bernstein.
The goal is to precisely predict the volume of water that will come from the Sierra snowpack, how fast it will melt, where it will flow and how soon, the researchers in charge say. Another improvement is having all this information within 24 hours.
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