The drought-stricken state of California has managed to pull itself out of the dry conditions it has been facing for months, with nearly half the state currently classified as drought-free.
Data from the US Drought Monitor shows that 44.66 percent of the state was free of drought conditions as of March 14, a jump from the 26.84 percent recorded on March 7 just a week earlier.
Additionally, the 19 percent of the state that suffered a “severe drought” on March 7 also fell to 8.49 percent this week. Six months ago, on September 27, 2022, 53 percent of California suffered in “severe drought,” 24.32 percent in “extreme drought,” and another 16.57 percent in the highest rating, “extraordinary drought.”
This may be related to the heavy rain and snowfall across the state stemming from the atmospheric river storms that have hit California in recent weeks. This rainfall is badly needed as California has suffered a mega drought for the past two decades but has also resulted in massive flooding across the state.
A “mega drought” is a prolonged period of low rainfall over several years, with the current drought being the longest and driest period in the western United States in more than 1,000 years. The current mega drought began around the year 2000.
“This region of the Americas has had long periods of drought, with perhaps two or three mega-droughts per century for the last 2,000 years, Hydrology at the University of Reading in the UK previously reported news week.
This – along with the growing population in the western US – has reduced the amount of water available for humans and agriculture.
“Water availability is always a balance between supply and demand,” said Rick Relyea, director of the Darrin Fresh Water Institute at Rensselaer Polytechnic Institute, New York news week in January. “Cities in many regions of the western United States have experienced rapid growth over the past century, but water supplies have remained relatively constant. When the mega-drought began, it led to a drop in water availability while water demand continued to increase.”
Recent rains will help replenish reservoirs that emptied as a result of dry and hot conditions in the summer of 2022.
Richard G. Luthy, a professor of civil and environmental engineering and a water infrastructure expert at Stanford University, previously said news week. “The recent rains are very important to prevent another dry year. 2020, 2021 and 2022 were exceptionally dry years. In 2022, January, February and March — typically wet months — were the driest on record in the late 18th century.”
However, much more rainfall is needed to fully bring the state out of the drought and cure the mega-drought once and for all. This is because groundwater supplies have been slowly depleted over the past 20 years, causing the soil itself to become dry and arid.
“In the last 25 years we have lost more than 150 km3 [121,600,000 acre feet] of groundwater from California that would have to be replaced by rain for many, many years even if there were no consumptive uses for municipal or agricultural purposes,” said Aakash Ahamed, a hydrologist and co-founder of the Water Data Lab news week in October last year.
Therefore, in order to fully overcome the drought, this groundwater must be replenished.
“It’s going to be several years of above-average rainfall — both rain and snow at appropriate times of the year,” said Lara Fowler, environmental and energy advocate and interim director of the Penn State Sustainability Institute at Penn State University, previously news week.
“As soil moisture and surface water supplies are depleted, increasing groundwater pumping has also led to a drop in groundwater levels in many places. Such groundwater contributes to the ground flow in streams. So not only surface water (streams/rivers) would be needed for replenishment, but also soil moisture and water tables (the latter of which can be replenished very slowly).”
This may be helped by new legislation from the California State Water Resources Control Board and the US Bureau of Reclamation, which plan to remove more than 600,000 acre-feet from the San Joaquin River to restore water tables Los Angeles Times reported this week.
However, the effects of climate change may complicate drought control as it is expected to only make dry conditions worse: one nature climate change A study published in 2022 showed that climate change was due to 42 percent of the arid and hot conditions in the United States over the past two decades.
“We know that climate change as a result of human activities is already making droughts worse. This is due to changing weather patterns, which are affected by changes in temperature in the oceans and atmosphere, partly because warmer air contains more moisture. This is one of the reasons why extreme weather events are becoming more extreme – heavy rains can be even heavier and droughts can last longer,” Cloke said.
Despite these challenges to California’s future, the drought is easing for the time being and the rains continue to pour.
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