Subscribe free to our newsletters via your
. 24/7 Space News .




EARTH OBSERVATION
NASA Data Find Some Hope for Water in Aral Sea Basin
by Staff Writers
Washington DC (SPX) Feb 19, 2014


Decreasing rainfall in the region has been widely reported, and the researchers wanted to quantify its role in the water loss. They were unable to find a complete and reliable published rainfall record for the entire watershed using ground-based measurements, so they analyzed rainfall data from NASA's Tropical Rainfall Measuring Mission satellite. To watch the Aral Sea change thropugh the period 2000-2013 please go here.

A new study using data from NASA satellite missions finds that, although the long-term water picture for the Aral Sea watershed in Central Asia remains bleak, short-term prospects are better than previously thought.

Once the fourth largest inland sea in the world, the Aral Sea has lost 90 percent of its water volume over the last 50 years. Its watershed -- the enormous closed basin around the sea -- encompasses Uzbekistan and parts of Tajikistan, Turkmenistan, Kyrgyzstan and Kazakhstan.

Graduate student Kirk Zmijewski and assistant professor Richard Becker of the University of Toledo, Ohio, wanted to find out whether all of the water was gone for good, or whether some of it might have ended up elsewhere in the watershed, behind dams or in aquifers. They also wanted to gauge whether decreasing rainfall has contributed to the catastrophic water loss.

The researchers used data from NASA's Gravity Recovery and Climate Experiment (GRACE) satellites to map monthly changes in mass within the watershed from 2003 to 2012. These changes are associated with changes in water volume, both on and below the land surface. They mapped the entire Aral Sea watershed, which is more than twice the size of Texas at 580,000 square miles (1.5 million square kilometers).

Zmijewski and Becker found that each year throughout the decade, the watershed lost an average of 2.9 to 3.4 cubic miles (12 to 14 cubic kilometers) of water, or the equivalent of one Lake Mead per year. That's a sobering rate of loss, but it's only about half as much as the rate at which the Aral Sea itself is losing water (5.8 cubic miles or 24 cubic kilometers).

"That means that roughly half the water lost from the Aral Sea has entirely left the watershed, by evaporation or agricultural uses, but half is upstream within the watershed," said Becker.

Specifically, more water is now in the central part of the watershed, where almost all of the region's farming takes place. That area increased in mass during the last four years of the study. The researchers believe that some of the increase comes from improvements in water conservation practices, though some was simply the result of inefficient irrigation, for example, water seeping out of unlined ditches into aquifers.

Decreasing rainfall in the region has been widely reported, and the researchers wanted to quantify its role in the water loss. They were unable to find a complete and reliable published rainfall record for the entire watershed using ground-based measurements, so they analyzed rainfall data from NASA's Tropical Rainfall Measuring Mission satellite.

Unexpectedly, they found no change in precipitation since 2002. "That was more surprising to us than anything else," said Becker. To check that result, they extended their analysis back to 1980, using data from the Global Precipitation Climatology Project for the earlier years. There was no sign of dwindling precipitation for the watershed across the entire 30-year period.

Patterns of rainfall have shifted near the Aral Sea, Becker pointed out, and that may have misled observers into believing that rain was decreasing overall. "Lake-effect precipitation downwind of the Aral Sea has decreased, but precipitation over the sea itself has increased, so that's not changing the whole system," he said.

The basin's water woes began in the 1930s with a Soviet development plan to create a cotton industry in the Central Asian desert. Rivers flowing into the Aral Sea were diverted to nourish the thirsty crop, setting off the inland sea's decline. Since the breakup of the Soviet Union, several watershed countries have maintained a cotton-based economy.

Declining availability of freshwater due to human activities and climate change is a critical issue throughout the world, affecting agriculture, economics and politics. Becker said, "When water is removed from the watershed, agricultural prospects in the region decline. It's hopeful that investments in irrigation upgrades have decreased water losses. With savvy water policy, each country in the watershed could continue to improve in the future."

The research was published January 31 in the journal Earth Interactions.

.


Related Links
GRACE
Earth at NASA
Earth Observation News - Suppiliers, Technology and Application






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








EARTH OBSERVATION
Glowing plants a sign of health
Paris (ESA) Feb 18, 2014
Radiant skin is considered a sign of good health in humans, but plants also glow when they are well. A potential new ESA satellite could use this fluorescence to track the health and productivity of vegetation worldwide. The Florescence Explorer, or FLEX for short, is a candidate for ESA's eighth Earth Explorer. It aims to provide global maps of vegetation fluorescence, which can be used t ... read more


EARTH OBSERVATION
Lunar ownership laws: a future necessity?

Chang'e-2 lunar probe travels 70 mln km

LADEE Sends Its First Images of the Moon Back to Earth

Source of 'Moon Curse' Revealed by Eclipse

EARTH OBSERVATION
NASA Mars Orbiter Views Opportunity Rover on Ridge

Curiosity Adds Reverse Driving for Wheel Protection

Curiosity Drives On After Crossing Martian Dune

The World Above and Beyond

EARTH OBSERVATION
Orion Underway Recovery Testing Begins off the Coast of California

Inside astronaut Alexander's head

NASA Welcomes University Participants to Develop Science Payloads

Boeing Commercial Crew Program Passes NASA Hardware, Software Reviews

EARTH OBSERVATION
No Call for Yutu

What's up, Yutu

China's Jade Rabbit rover comes 'back to life'

Yutu Awakes

EARTH OBSERVATION
NASA, International Space Station Partners Announce Future Crew Members

Andrews Space Cargo Module Power Unit Provides Power For Payloads Bound For ISS

Russian Progress M-22M docks with ISS following fast rendezvous

Russian Resupply Spacecraft Begins Expedited Flight to Station

EARTH OBSERVATION
Arianespace to launch OPTSAT 3000 and VENuS satellites

Amazonas 4A is prepared for Arianespace's second Ariane 5 flight of 2014

New Russian Rocket Mock-Up Rolls Out to Launch Pad

Lighter engines a headache for satellite launcher Ariane

EARTH OBSERVATION
Scientist: Exoplanet research needs less hype, more patience

Europe sets plans for 2024 planet-hunting mission

ESA selects planet-hunting PLATO mission

Rife with hype, exoplanet study needs patience and refinement

EARTH OBSERVATION
Physicists produce a potentially revolutionary material

ASC Signal Selected by Newtec to Provide Transmit Receive Satellite Antennas for Pan-European Network

It's alive! Bacteria-filled liquid crystals could improve biosensing

Ancient helium rising to the surface in Yellowstone National Park




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.