The 16 major aquifers in blue, by contrast, gained water during that period. Click to enlarge:. The researchers found that 13 basins around the world — fully one-third of the total — appeared to be in serious trouble. Eight aquifer systems could be categorized as "overstressed": that is, there's hardly any natural recharge to offset the water being consumed.
In the direst state was the Arabian aquifer system beneath Saudi Arabia and Yemen, which provides water for 60 million people and is being depleted by irrigation for agriculture. Another five aquifer systems were categorized as "extremely" or "highly" stressed — they're being replenished by some rainwater, but not nearly enough to offset withdrawals. That list includes the aquifers underneath California's Central Valley.
During California's recent brutal, five-year drought, many farmers compensated for the lack of surface water by pumping groundwater at increasing rates. There are few regulations around this, though California's legislature recently passed laws that will gradually regulate groundwater withdrawals. The result? The basins beneath the Central Valley are being depleted, and the ground is actually sinking, which in turn means these aquifers will be able to store less water in the future. Farmers are losing a crucial buffer against both this drought, if it persists, and future droughts.
Here's the other troubling bit: It's unclear exactly when some of these stressed aquifers might be completely depleted — no one knows for sure how much water they actually contain. In a companion paper in Water Resources Research , the researchers took stock of how little we know about these basins. Twenty-one aquifers have exceeded sustainability tipping points and are being depleted, and 13 of these are considered significantly distressed, threatening regional water security and resilience.
NASA scientists used GRACE data to identify regional trends of freshwater movement, and combined that information with data from other satellites, climate models and precipitation measurements to d Static Gravity Field Anomalies. You may have lived in a city where you were allowed to water Below a certain depth, the ground, if it is permeable enough to hold water, is saturated with water. The upper surface of this zone of saturation is called the water table.
The saturated zone beneath the water table is called an aquifer, and aquifers are huge storehouses of water. What you are looking at in this photo is a "well" that exposes the water table, with an. The ground beneath our feet is not just rock, or at least, not just one kind of rock.
Many different types of rock exist, and they have very different properties. Often, different types of rocks exist in horizontal layers beneath the land surface.
Some layers are more porous than others, and at a certain depth below ground the pores and fractures in these rocks can be. Pumping has removed water from storage in basalt aquifers and caused declines in many areas of the Columbia Plateau. Skip to main content. Search Search. Water Science School. Aquifers and Groundwater. Groundwater Photo Gallery Learn about groundwater through pictures Visit the gallery. Get GW data. Groundwater Information by Topic Learn more.
Science Center Objects Overview Related Science Publications Multimedia A huge amount of water exists in the ground below your feet, and people all over the world make great use of it.
Learn the basics about water using our Water Primers! Credit: Environment and Climate Change Canada. Below are other science topics related to aquifers and groundwater. Date published: October 9, Filter Total Items: 7. Year Select Year Apply Filter. Date published: November 8, Date published: June 18, Date published: June 11, Date published: June 6, Attribution: Water Resources.
Year Published: A primer on ground water Most of us don't have to look for water. Baldwin, Helene L. View Citation. Filter Total Items: 3. Year Published: Ground water and surface water: A single resource The importance of considering ground water and surface water as a single resource has become increasingly evident.
Winter, Thomas C. Lehn; Alley, William M. Gender and water Water and climate Water and the Agenda. Nov 09, Floods to avert droughts in Jordan using the force of nature. Groundwater Cities Disaster risks and water Indigenous knowledge Water governance Water scarcity.
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