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September 4, 2003
NASA Helping to Understand Water Flow in the West
To do their jobs, water resource managers in the Columbia River Basin
have mostly relied on data from sparsely located ground stations among
the Cascade Mountains in the Pacific Northwest. But now, NASA and partnering
agencies are going to provide United States Bureau of Reclamation water
resource managers with high resolution satellite data, allowing them
to analyze up-to-date water-related information over large areas all
at once.
The pilot program is now underway with the Rio Grande and Columbia River
basins where water is scarce while demands range from hydropower, to
farming, fishing, boating and protecting endangered species. Water resource
managers in these areas grapple with the big money stakes of distributing
a finite amount of water to many groups. NASA satellite data offer to
fill the data gaps in mountainous and drought-ridden terrain, and new
computer models let users quickly process that data.
Land Surface Models (LSMs) from NASA, other agencies and universities,
and NASA satellite data can be used to determine snowpack, amounts of
soil moisture, and the loss of water into the atmosphere from plants
and the soil, a process known as evapotranspiration. Understanding these
variables in the water cycle is a key to managing water in such resource-limited
areas.
"The latest satellites provide so much up-to-date and wide-ranging data,
which we can use in the models to monitor and better understand what
is happening with the water cycle in these areas," said Kristi Arsenault,
research associate for the Land Data Assimilation System (LDAS) team
at NASA‚s Goddard Space Flight Center, and Research Associate at University
of Maryland, Baltimore County.
"These efforts are designed to improve the efficiency of the analysis
and prediction of water supply and demand using the emerging technologies
of the Land Data Assimilation System," said Dr. Dave Matthews, manager
of the River Systems and Meteorology Group of the Technical Services
Center, U.S. Bureau of Reclamation (Reclamation). Computer models, known
as decision support systems, that factor in ecological, human, and legal
restrictions are vital to managing and allocating water, Matthews added.
These systems will incorporate NASA satellite and model data.
NASA's tools may be of vital use in the Rio Grande and Columbia River
basins where the disparate and numerous water demands have enormous economic
implications. In the Rio Grande Basin, for example, water managers dole
out water to farmers so they can irrigate their land. At the same time,
under the Endangered Species Act, states are required by law to maintain
river water levels to protect the habitat of the endangered silvery minnow.
A recent seven-year drought has exacerbated these demands.
Similarly, the Columbia River Basin provides water for the Coulee Dam,
the largest concrete dam in North America, and a means for controlling
floods. This hydroelectric dam is the third largest producer of electricity
in the world. At the same time, the basin is a source of water for a
billion dollar agricultural area.
To help make big decisions of allocating water, NASA's special technologies
can provide a unique perspective from space. For example, satellites
can classify vegetation, a task that is essential to calculating evapotranspiration,
which accounts for up to 60 percent of water loss into the air in a region
like the Rio Grande Basin. Some managers have been relying on vegetation
maps that dated back to 1993, in areas where wild-lands, crops and farming
practices are subject to change.
Landsat data can provide highly detailed spatial information, but these
images may only be available once a month, and are very expensive. The
newer technologies of the Moderate Resolution Imaging Spectroradiometer
(MODIS) instrument on the Terra and Aqua satellites provides more frequent
passes and day-to-day and week-to-week changes in vegetation production.
In addition, other variables of interest, like snow cover and land surface
temperatures, are updated more regularly by MODIS, which can aid in identifying
areas with potential flooding and help with the daily management of the
water resources.
LDAS has also begun to evaluate soil moisture data from NASA‚s Advanced
Microwave Scanning Radiometer (AMSR-E) aboard the Aqua satellite and
3-hour rainfall estimates from NASA‚s Tropical Rainfall Measuring Mission.
All this data helps determine how much water is being absorbed into the
ground, versus how much is evaporating into the atmosphere. These observations
will then be assimilated into Land Surface Models so that water managers
can assess flood risks and other factors and act accordingly in a timely
manner.
Reclamation brings water to more than 31 million people and provides
one out of five Western farmers with irrigation water for 10 million
acres of farmland.
One mission of NASA's Earth Science Enterprise is to expand and accelerate
the realization of economic and societal benefits from Earth science
information and technology.
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Lindsay Renick Mayer / Krishna Ramanujan
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-3026)
kramanuj@pop900.gsfc.nasa.gov |
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Map of Rio Grande and Columbia River Basins
Credit: Image by Robert Simmon, NASA GSFC Earth Observatory, Michael
Tischler, NASA/GSFC.
Rio Grande River Basin, SeaWiFS Image with MODIS Higher Resolution
Inset
This graphic shows a larger view (1 kilometer resolution) of the Rio
Grande River basin taken by the Sea-viewing Wide Field-of-view Sensor
(SeaWiFS) on the OrbView-2 satellite, with an inset of the same area
(250 meter resolution) taken by the Moderate Resolution Imaging Spectroradiometer
(MODIS) instrument aboard the Terra satellite. In the inset, the red
areas depict vegetation, and the largest dark area indicates Elephant
Butte Reservoir.Credit: Image by Andrew French of NASA GSFC/NRC, Kristi
Arsenault, NASA GSFC and Univ. of Maryland-Baltimore County.
MODIS Image of Columbia River Basin Snowcover, February 24, 2003
This image from the Moderate Resolution Imaging Spectroradiometer (MODIS)
shows snowcover for the Columbia River Basin in the Cascade Mountains
of Washington State, taken on February 24, 2003 (250 meter resolution).
Credit: Jeff Schmaltz MODIS Land Rapid Response Team, NASA/GSFC
MODIS Image of Rio Grande River Basin, February 22, 2003
This image from the Moderate Resolution Imaging Spectroradiometer (MODIS)
shows the Rio Grande River Basin taken on February 22, 2003 (250 meter
resolution). Credit: Jeff Schmaltz MODIS Land Rapid Response Team, NASA/GSFC
U.S. Rainfall (July 1 to 15, 2002)
This animation shows 3-hourly rainfall from July 1 through 15, 2002.
Rainfall is one of the main variables that drive land surface models
used by water resource managers and scientists. Credit: Images by Robert
Simmon, NASA GSFC Earth Observatory, based on data provided by Kristi
Arsenault, NASA GSFC and Univ. of Maryland-Baltimore County.
U.S. Soil Moisture (July 1 to 15, 2002)
This animation shows changes in soil moisture from July 1 through 15,
2002, derived from a land surface model. Soil moisture is important for
knowing how much water is contained in the soil, which is vital for crop
production, flood prediction, and evapotranspiration estimates. Credit:
Images by Robert Simmon, NASA GSFC Earth Observatory, based on data provided
by Kristi Arsenault, NASA GSFC and Univ. of Maryland-Baltimore County.
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