Posts Tagged ‘water’

When in Drought…

December 12th, 2011 by Sarah Pryputniewicz

New groundwater and soil moisture drought indicator maps produced by NASA are available on the National Drought Mitigation Center’s website. They currently show unusually low groundwater storage levels in Texas. The maps use an 11-division scale, with blues showing wetter-than-normal conditions and a yellow-to-red spectrum showing drier-than-normal conditions. (Credit: NASA/National Drought Mitigation Center)

GRACE groundwater map of continental U.S.

The map (above) shows the change in stored groundwater in the contiguous United States.  Texas, which experienced record heat and wildfires this summer, is experiencing a very severe drought.  The change in stored water should not be a surprise given the weather conditions of the past year.  (By contrast, New England has a surplus of water from a very wet summer and the remnants of Hurricane Irene.)

Drought maps offer farmers, ranchers, water resource managers and even individual homeowners a tool to monitor the health of critical groundwater resources. “People rely on groundwater for irrigation, for domestic water supply, and for industrial uses, but there’s little information available on regional to national scales on groundwater storage variability and how that has responded to a drought,” Matt Rodell, a hydrologist at NASA’s Goddard Space Flight Center, said. “Over a long-term dry period there will be an effect on groundwater storage and groundwater levels. It’s going to drop quite a bit, people’s wells could dry out, and it takes time to recover.”

The question is: how long will it take to replenish the water that has been removed from the aquifers in Texas? Matt Rodell estimates, “Texas groundwater will take months or longer to recharge.  Even if we have a major rainfall event, most of the water runs off. It takes a longer period of sustained greater-than-average precipitation to recharge aquifers significantly.”

Water is a resource that everyone needs.  In dry environments, such as southwestern Texas, water is especially precious.  Water is used for the usual personal purposes, for agricultural purposes, and in natural gas wells.  For example, accessing the natural gas in the Eagle Ford shale deposit, which runs from the Mexican border towards Houston and Austin, requires millions of gallons of water to fracture the shale and release the stored hydrocarbons.

The prolonged Texas drought is putting more pressure on local officials about how best to use the limited amount of groundwater.  What is the best way to use the water supply?  Who gets first dibs?  How much should different businesses pay for water?  These are highly-important questions that can only be answered with a full understanding of how groundwater works.

You can explore how groundwater flows and propose solutions to water-supply issues in the High-Adventure Science water investigation.

http://www.nasa.gov/topics/earth/features/tx-drought.html

Drought spurring fracking concerns

Oil’s Growing Thirst for Water

Texas

Finding Fossil Aquifers on Earth

October 5th, 2011 by Sarah Pryputniewicz

NASA technology is being used to find fossil aquifers underneath Earth’s driest deserts.  This technology was developed to explore underneath the surface of Mars, to help determine if there might be water on the red planet.  Water is a sign that life might be possible.

Why are they using this technology on Earth?  We know that there is water on Earth; we know that there is life on Earth.

Firstly, it’s the only way that scientists can “see” underground structures.

“This demonstration is a critical first step that will hopefully lead to large-scale mapping of aquifers, not only improving our ability to quantify groundwater processes, but also helping water managers drill more accurately,” said Muhammad Al-Rashed, director of Kuwait Institute for Scientific Research’s Division of Water Resources.

We might have a lot of water on Earth, but it’s not distributed equally.  Knowing the availability of the water supply helps us to use it in a sustainable manner.

Secondly, it’s a good way to study the climactic history of these regions.

“This research will help scientists better understand Earth’s fossil aquifer systems, the approximate number, occurrence and distribution of which remain largely unknown,” said Essam Heggy, research scientist at NASA’s Jet Propulsion Laboratory. “Much of the evidence for climate change in Earth’s deserts lies beneath the surface and is reflected in its groundwater. By mapping desert aquifers with this technology, we can detect layers deposited by ancient geological processes and trace back paleoclimatic conditions that existed thousands of years ago, when many of today’s deserts were wet.”

Previously, climate research has focused on Earth’s polar regions and forests.  It is important to study those areas, but arid and semi-arid regions make up a big part of the planet, and they should be studied too.

This is a great story that shows how technology developed for one area of research can often be useful for several other fields of science–all of which are highlighted in our High-Adventure Science investigations!

Learn about searching for water on other planets in the High-Adventure Science space investigation, learn about aquifers and water sustainability in the High-Adventure Science water investigation, and learn about using geologic formations to reconstruct previous climates in the High-Adventure Science climate investigation.

http://www.sciencedaily.com/releases/2011/09/110915182850.htm

Irrigation and Climate Change

September 19th, 2011 by Sarah Pryputniewicz

What does irrigation have to do with climate change?  Possibly a lot.

According to a new study from the University of Wisconsin-Madison, irrigation has increased agricultural productivity by an amount roughly equivalent to the entire agricultural output of the United States.  That’s a lot of increased productivity!

All of those growing plants take up more carbon dioxide, which could lead to slowing global warming.  But without the extra water required for irrigation, not as much carbon dioxide would be taken up by plants–and that could lead to more warming.

The study also shows quantitatively that irrigation increases productivity in a nonlinear fashion — in other words, adding even a small amount of water to a dry area can have a bigger impact than a larger amount of water in a wetter region. “More irrigation doesn’t necessarily mean more productivity,” Ozdogan says. “There are diminishing returns.”

This was already known on the field scale, he says, but is true globally as well. Interestingly, he found that, on average, worldwide irrigation is currently conducted close to the optimal level that maximizes gains. While this may be good news for current farmers, it implies limited potential for irrigation to boost future productivity even as food demands increase.

So what does this mean for us?

Be mindful of the amount of water that we use so that we can continue to irrigate fields, grow food to feed ourselves, and, along the way, reduce the amount of carbon dioxide in the atmosphere.

Learn about fresh water availability and climate change in our High-Adventure Science investigations.

http://www.sciencedaily.com/releases/2011/08/110825152457.htm

Raising the water table the natural way

August 30th, 2011 by Sarah Pryputniewicz

Today’s Wall Street Journal ran a story about using beavers to raise the water table and rehabilitate natural areas.  Beavers?  How can beavers do this?

Photo by Walter Siegmund Beaver dam of Hat Lake and Hat Creek in foreground.  Bridge over Hat Creek on highway 89, Lassen Volcanic National Park. http://en.wikipedia.org/wiki/File:BeaverDam_8409.jpg

Beavers are rodents that live in and along streams and rivers.  They gnaw down trees and build dams, which back up the rivers and streams.  The standing water behind the dam can percolate into the ground, recharging the groundwater and raising the water table.  The dams minimize flooding during the wet season and keep water from drying up during the dry season.

It’s especially important to recharge the groundwater in areas that don’t have precipitation throughout the year.  As we draw water out of the ground for our own uses, the water table falls, so much so that natural watering holes dry up.  One solution is for us to simply use less water during the dry seasons.  Another solution for humans to build dams.  Using less water is a good start (for as much as that is possible during the dry season), but we can also turn to natural sources–such as beavers–to recharge the water supply AND restore natural habitats.

“We can spend $200,000 putting wood into a stream, cabling down logs. Sometimes it works and sometimes it doesn’t.  Put in a colony of beavers and it always works.”

-Celeste Coulter, stewardship director at the North Coast Land Conservancy, a Seaside, Oregon, group that urges developers to set aside land for beavers

Learn about the science behind groundwater recharge and the water table in the High-Adventure Science investigation, “Will there be enough fresh water?”.

http://online.wsj.com/article/SB10001424053111904253204576512391087253596.html?mod=ITP_AHED#articleTabs%3Darticle

Missing: Fresh Groundwater

January 6th, 2011 by Sarah Pryputniewicz
Where has all the groundwater gone, long time passing? (My apologies to Pete Seeger and Joe Hickerson.)
It’s gone into the sea.
Scientists in the Netherlands have made the shocking discovery that much of the water pumped out of the ground evaporates and ends up in the oceans.  Amazingly, this raises the sea level by 0.8 millimeters per year.  That doesn’t sound like a lot, but to put it in perspective, that’s roughly the same amount of sea level rise caused by melting glaciers and icecaps outside of Greenland and Antarctica and 25% of the total sea level rise per year!
http://www.sciencedaily.com/releases/2010/09/100923142503.htm