Hydrological Drought, as opposed to Meteorological Drought, is the deux ex machina of California drought mongers
I grew up in California. Since the mid 1970’s the phrase “but the drought’s not over” became so repetitive in state government and media communications that it was a running joke for more than four decades between my brother and I, until he finally passed away. This drumbeat began long before “Climate Change” or “Global Warming” became widespread issues of concern. The corollary to “but the drought’s not over” was the proclamation by government and media every single late spring or early summer that:
“Because we had X winter, it’s going to a bad fire season”
X could be dry: dehydrated conditions susceptible to easy ignition.
X could be wet: Overgrowth of brush will turbocharge fires with excessive fuel.
Here’s the conditions today vs. three years ago. Use the slider to see the difference.
Now Let’s take a walk through a decade of endless drought caterwauling.
Click here to go directly to a full overview current conditions in California and skip the walk.
National Geographic, February 13th 2014
Two years into California’s drought, Donald Galleano’s grapevines are scorched shrubs, their charcoal-colored stems and gnarled roots displaying not a lick of life. “I’ve never seen anything like this,” says Galleano, 61, the third-generation owner of a 300-acre vineyard in Mira Loma, California, that bears his name. “It’s so dry … There’s been no measurable amount of rain.”
California is experiencing its worst drought since record-keeping began in the mid 19th century, and scientists say this may be just the beginning. B. Lynn Ingram, a paleoclimatologist at the University of California at Berkeley, thinks that California needs to brace itself for a megadrought—one that could last for 200 years or more.
Proceedings of the National Academy of Sciences, March 2nd 2015
We therefore conclude that anthropogenic warming is increasing the probability of co-occurring warm–dry conditions like those that have created the acute human and ecosystem impacts associated with the “exceptional” 2012–2014 drought in California.
Of course who would quickly to appear to write about and emphasize the study noted above?
National Library of Medicine/PNAS, March 23rd 2015
Diffenbaugh et al. (2) seem to solve that mystery in their latest assessment. As noted earlier in Fig. 1, recent years haven’t just been hot and they haven’t just been dry: they’ve been very hot and very dry at the same time. Climate change appears to be
Diffenbaugh et al. now add weight to the accumulating evidence that anthropogenic climatic changes are already influencing the frequency, magnitude, and duration of drought in California.
increasing the likelihood of a large-scale atmospheric pattern that yields warm, dry weather in California. That’s a double whammy when it comes to the hydrological balance that governs drought: less precipitation and more evaporation and transpiration, at the same time. Combined with the role that temperature plays in increasing the loss of water from agriculture, soils, surface water bodies, and snowpack, the authors note that 100% of the moderately dry years between 1995 and 2014 co-occurred with a positive temperature anomaly. Diffenbaugh et al. (2) note:
NOAA/Climate.gov, August 4th, 2016
Several recent studies have found that drought conditions in California have become increasingly more intense and longer-lasting (footnote 3). Some of our research has linked this tendency to the combination of strong ENSO events and global warming (Yoon et al. 2015). We’ve found that strong ENSO events modulate California’s climate not only through the peak of El Niño and La Niña, but also their transition phases when they dissipate, and before another El Niño or La Niña potentially forms.
https://www.climate.gov/news-features/blogs/enso/long-arm-california-drought
Of course, the rains returned for a couple of years, tamping down the doom casting a bit.
Weather.com, January 12th, 2017
The snow and rain that have pummeled California in recent days have helped to eliminate the drought in parts of northern California.
According to the Drought Monitor analysis released Thursday, all of northern California north of Interstate 80 is now free of drought.
If this active storm pattern continues through the next couple of months, substantial drought relief is possible. But it will likely take multiple near to above-average wet seasons to completely replenish reservoirs and ground water and to end the state’s multi-year drought.
But remember, it’s California AND THE DROUGHT’S NOT OVER!
Wired, January 22nd, 2017
Even in a wet year in California, nature’s bounty of water is no longer enough to satisfy all the state’s demands, recharge overdrafted grou ndwater basins in the San Joaquin valley, or overcome the massive deficits suffered by California’s ecosystems and endangered fisheries. Far more water has been claimed on paper than can ever be reliably and consistently delivered to users. If the most straightforward definition of drought is the simple mismatch between the amounts of water nature provides and the amounts of water that humans and the environment demand, California is in a permanent drought.
Not long after the above article we had the Oroville Dam Crisis.
In February 2017, heavy rainfall damaged Oroville Dam‘s main and emergency spillways, prompting the evacuation of more than 180,000 people living downstream along the Feather River and the relocation of a fish hatchery.
Heavy rainfall during the 2017 California floods damaged the main spillway on February 7, so the California Department of Water Resources stopped the spillway flow to assess the damage and contemplate its next steps. The rain eventually raised the lake level until it flowed over the emergency spillway, even after the damaged main spillway was reopened. As water flowed over the emergency spillway, headward erosion threatened to undermine and collapse the concrete weir, which could have sent a 30-foot (10 m) wall of water into the Feather River below and flooded communities downstream. No collapse occurred, but the water further damaged the main spillway and eroded the bare slope of the emergency spillway.
AccuWeather, January 29th, 2018
“You can trace this multi-year drought back to 2011,” Andrews said.
Despite plenty of rain and snowfall last winter, which ended the state’s five-year drought, it wasn’t enough to keep drought conditions from quickly coming back.
Over 54 percent of California is experiencing abnormally dry conditions, while just over 12 percent of the state is under moderate drought conditions, according to the United States Drought Monitor.
“That is very worrisome for the region’s water supply and fire danger,” Andrews warned.
Bloomberg , January 17, 2019
California’s wildfire season used to last a few months. Now the state burns all year.
Global warming has intensified California’s cyclical droughts, leaving the land riddled with pockets of dry brush that persist even amid winter rains.
Science, April 17th, 2020
A trend of warming and drying
Global warming has pushed what would have been a moderate drought in southwestern North America into megadrought territory. Williams et al. used a combination of hydrological modeling and tree-ring reconstructions of summer soil moisture to show that the period from 2000 to 2018 was the driest 19-year span since the late 1500s and the second driest since 800 CE (see the Perspective by Stahle). This appears to be just the beginning of a more extreme trend toward megadrought as global warming continues.
The Guardian, January 7th, 2021
A creeping trend
Drought is not unnatural for California. Its climate is predisposed to wet years interspersed among dry ones. But the climate crisis and rising temperatures are compounding these natural variations, turning cyclical changes into crises.
https://www.theguardian.com/us-news/2021/jun/07/california-drought-oregon-west-climate-change
CAL MATTERS, May 18th 2021
In his 1952 novel, East of Eden, John Steinbeck depicted the yin and yang of California’s water cycle in the Salinas Valley where he grew up, how the bounty of the wet years drove out memories of the dry, until, predictably, the water wheel came back around. “And it never failed that during the dry years the people forgot about the rich years, and during the wet years they lost all memory of the dry years. It was always that way.”
…
But droughts and water shortages are more of a persistent way of life now in California than a mere cycle. The rare has become the routine.
Of all the lessons the state should learn, this might be the most valuable: “There’s never enough water in California,” the Pacific Institute’s Gleick said. “We have to assume that we are always water-short and we have to act like it.”
https://calmatters.org/environment/2021/05/unprepared-california-drought-2021-lessons-learned/
Yale Climate Connections, June 8th, 2021
Changing climate is supercharging southwestern droughts
According to the 2020 study in Science cited earlier, human-caused climate change made southwestern drought conditions between 2000 and 2018 about 46% more intense than they would have been naturally, “pushing an otherwise moderate drought onto a trajectory comparable to the worst [U.S. southwest] megadroughts since 800 CE,” the heyday of the Mayan civilization.
https://yaleclimateconnections.org/2021/06/california-americas-garden-is-drying-out
CAL MATTERS, September 28th 2022
Conditions are shaping up to be a “recipe for drought”: a La Niña climate pattern plus warm temperatures in the Western Tropical Pacific that could mean critical rain and snowstorms miss California, according to Daniel Swain, a climate scientist with UCLA and The Nature Conservancy.
…
“One thing that is unfortunately becoming easier to anticipate are warmer than average conditions due to climate change,” Swain said.
https://calmatters.org/environment/2022/09/california-drought-likely-to-continue/
Then rainy winters return.
BUT THE DROUGHT’S NOT OVER!
NPR March, 23rd 2023
California’s groundwater drought is still bad
When California’s reservoirs declined, many cities and farmers turned to another water source: vast aquifers underground.
In drought years, groundwater has supplied up to 60% of California’s water. But the pumping has been largely unregulated. So over the decades, water levels have fallen dramatically in California’s aquifers. Before this winter, some groundwater wells were at the lowest points ever recorded. That’s because in the Central Valley, groundwater hasn’t been replenished after previous droughts.
“Groundwater is the dark matter of the hydrologic cycle,” says Graham Fogg, professor emeritus of hydrogeology at the University of California Davis. “The fact that these are such huge volumes of water allows them to take a lot of abuse and to be depleted year after year.”
Then finally, some “experts” admit it’s wet.
Accuweather, March 4th 2024
In the wake of a biblical blizzard that unloaded nearly 100 inches of snow on California, AccuWeather is making a major announcement: California will be free of widespread drought through at least 2025.
“The combination of the abundance of rain and snow from the winter of 2022-2023, the state of the reservoirs, and what has happened this winter gives a high confidence that drought conditions will remain absent in California well into 2025,” AccuWeather California Weather Expert Ken Clark said.
Current California Conditions
Taking another look at the current USDM map of California
I’ve been watching this for the last month or two and the producers of this map are having trouble letting go of those little bits of yellow. They are clinging for dear life. It might surprise readers to know that this map is a subjective judgement, not an objective measure.
The map is made by people, not computers
The USDM map provides a “snapshot” of current conditions. Authors build upon the previous week’s map, identifying areas that might have changed in response to recent weather patterns. They bring together the physical climate, weather and hydrology data and reconcile that with local expert feedback, impact reports and conditions observations. The author is also responsible for weighing different indicators based on what’s most appropriate for a particular place and time of year. In the West, for example, winter snowpack has a stronger bearing on water supplies than in the East.
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To determine drought intensity, USDM authors use a convergence of evidence approach, blending objective physical indicators with insight from local experts, condition observations and reports of drought impacts. It is this combination of the best available data, local observations and experts’ judgment that make the U.S. Drought Monitor more versatile than other drought measures. Learn more with our convergence of evidence tutorial.
Because there is no blue, purple, or green indications on the Drought Monitor for excessively wet conditions, even if all of California was flooded, the most this map would ever show is white. It does not give an objective centered overview of the water state of the state.
The Current Snow Water Equivalent
Snow water equivalent (SWE) is defined as the depth of water that would result if the entire snowpack was melted. It represents the amount of liquid water contained within the snowpack, regardless of the actual depth or density of the snow. The significance of SWE is that it provides a standardized measure of the water content in snow, which is crucial for several water resource management. SWE data is used by water managers to estimate spring runoff and plan for water supply, irrigation, and hydropower generation.
And here is the current SWE for California. Not a record, but still 112% of average
The Current State of California Reservoirs
The Hydrological Conditions
Hydrological Drought, as opposed to Meteorological Drought, (precipitation below normal) is the deux ex machina of drought mongers as noted in one of the above article quotes.
Hydrological Drought is defined by deficiencies in surface and subsurface water supplies, such as low stream flows, reduced reservoir and lake levels, and declining groundwater tables. Hydrological Drought lags meteorological drought as it takes time for precipitation deficiencies to manifest in the water supply. In this way, poor water management can lead to a permanent crying of drought, for example when Central Valley farmers are forced to over-pump because the state sends water out to sea for environmental justifications.
In a series of strongly worded letters, nearly a dozen legislators — many from drought-starved agriculture regions of the Central Valley —have implored state and federal officials to relax environmental pumping restrictions that are limiting the amount of water captured from the delta.
“When Mother Nature blesses us with rain, we need to save the water, instead of dumping it into the ocean,” Assemblymember Vince Fong (R-Bakersfield) wrote in a letter to Gov. Gavin Newsom.
Nevertheless, two years of solid rain and snow have had a huge effect on the groundwater conditions in California, despite farmers being forced to rely on wells for decades due to the water policies of the state government.
Far more monitoring wells are currently above normal and more wells are at all time highs than those at all time lows.
(back to the walk through time)
But remember, this is California annnnndddd…..
THE DROUGHT’S NOT OVER!!!!
via Watts Up With That?
April 14, 2024 at 04:11PM
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