I’m a Scientist in #California. Here’s What Worries Me Most About #Drought — The New York Times

On September 4, 2021, the Joint Base Lewis-McChord Soldiers and the Bureau of Land Management-California’s Folsom Lake Veterans Hand Crew constructed a handline, cleared brush, and dealt with hot spots north of Lake Davis and Portola during the largest wildfire of 2021–California’s Dixie Fire. The western wildfires of 2021 were one of 20 separate billion-dollar disasters that struck the United States last year. (Joe Bradshaw/Bureau of Land Management)

Click the link to read the opinion piece on The New York Times website (Andrew Schwartz). Here’s an excerpt:

This past week, I joined teams of other scientists gathering the most important measurements of the Sierra Nevada snowpack from over 265 sites throughout the state. Typically, this measurement marks the transition from snow accumulation season to the melt season and contains the most snow of any measurement throughout the year. The 2022 results, however, confirmed what those of us monitoring the state’s drought had feared: California’s snowpack is now at 39 percent of its average, or 23 percent lower than at the same point last year. This signals a deepening of the drought — already the worst in the western United States in 1,200 years — and another potentially catastrophic fire season for much of the West.

Many people have a rather simplistic view of drought as a lack of rain and snow. That’s accurate — to an extent. What it doesn’t account for is human activity and climate change that are now dramatically affecting the available water and its management. As more frequent and large wildfires and extended dry periods batter the land, our most important tools for managing water are becoming less and less accurate. At the same time, our reliance on these models to try to make the most of the little water we have is becoming more and more problematic.

Droughts may last for several years or even over a decade, with varying degrees of severity. During these types of extended droughts, soil can become so dry that it soaks up all new water, which reduces runoff to streams and reservoirs. Soil can also become so dry that the surface becomes hard and repels water, which can cause rainwater to pour off the land quickly and cause flooding. This means we no longer can rely on relatively short periods of rain or snow to completely relieve drought conditions the way we did with past droughts…

Many storms with near record-breaking amounts of rain or snow would be required in a single year to make a significant dent in drought conditions. October was the second-snowiest and December the snowiest month on record at the snow lab since 1970, thanks to two atmospheric rivers that hit California. But the exceptionally dry November and January to March periods have left us with another year of below-average snowpack, rain and runoff conditions.

This type of feast-or-famine winter with big storms and long, severe dry periods is expected to increase as climate change continues. As a result, we’ll need multiple above-average rain and snow years to make up the difference rather than consecutive large events in a single year.

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