China's Three Gorges Dam (Forwarded)

ESA News
http://www.esa.int

1 August 2003

China's Three Gorges Dam

Water churns through diversion holes in the world's largest dam -- China's Three
Gorges project on the Yangtze River, imaged here by ESA's Proba satellite this
week. Seen to the left, the waters behind the dam have risen to a level of 135
metres since the sluice gates were first closed in early June, and in August
Three Gorges is due to generate its first commercial hydroelectricity.

The Three Gorges project is set to create a new 600-km-long body of water on the
face of the 21st century Earth: the thick concrete dam walls stand 190 metres
tall and already they hold back an estimated 10 billion cubic metres of water.
More than 600,000 people have had to abandon their homes to the rising
reservoir, and as many again will have to relocate before the waters reach their
final planned level of 175 metres.

It can be clearly seen in the image how the river has burst its banks and is
inundating the land upriver of the dam. The waters of the world's third-longest
river appear brown in colour because they are heavy with sediment.

Many environmentalists have campaigned against the Euro 20 billion-plus Three
Gorges project due to the drowning of multiple cultural heritage sites, the fear
that reservoir will collect industrial pollution and sewage that cannot now be
washed to the sea, and the risk posed to downstream populations if the dam
should ever break. But the Chinese government says the project will tame the
flood-prone Yangtze River and generate much-needed electricity for economic
development.

This 18-metre resolution image was acquired by the CHRIS sensor onboard Proba on
30 July 2003.

About Proba

Proba (Project for On Board Autonomy) is a micro-satellite the size of a small
box, launched by ESA in October 2001 and operated from ESA's Redu Ground Station
(Belgium). Orbiting 600 km above the Earth's surface, Proba was designed to be a
one-year technology demonstration mission but has since had its lifetime
extended as an Earth Observation mission. It now routinely provides scientists
with detailed environmental images thanks to CHRIS -- a Compact High Resolution
Imaging Spectrometer developed by UK-based Sira Electro-Optics Ltd -- the main
payload on the 100 kg spacecraft.

Proba boasts an 'intelligent' payload, has the ability to observe the same spot
on Earth from a number of different angles and can record images of an 18.6 km
square area to a resolution of 18 m. More than 60 scientific teams across Europe
are making use of Proba data. A follow-on mission, Proba-2, is due to be
deployed by ESA around 2005.

Related News

* Pinpoint accuracy with the Proba camera
http://www.esa.int/export/esaCP/ESAX...tecting_0.html
* Meet CHRIS -- the little camera that takes big pictures
http://www.esa.int/export/esaCP/ESAI...Kingdom_0.html

Related links

* Proba
http://www.esa.int/proba

IMAGE CAPTIONS:

[Image 1:
http://www.esa.int/export/esaCP/SEM4...reWeek_1.html]
Acquired 30 July 2003, this Proba shows the China's Three Rivers dam. The
Project for On-Board Autonomy (Proba) is a technology demonstration mission of
the European Space Agency.
CHRIS is a push-broom spectrometer capable of imaging up to 200 spectral bands
in the visible range. Together with the scanning and manoeuvring capabilities of
the spacecraft it supports Bidirectional Reflectance Distribution Function
(BRDF) measurements used in land, sea and atmospheric observations.

Technical Information:

Instrument: Compact High Resolution Imaging Spectrometer (CHRIS)
Date of Acquisition: 30-07-2003
Instrument Features: 3 bands (466nm, 543nm, 641nm) image, 15 m spatial
resolution, 768x1010 pixels

Credits: ESA

[Image 2:
http://www.esa.int/export/esaCP/SEM4...html#subhead1]
A Chinese man fishes as water flows through water diversion holes of the Three
Gorges Dam on the Yangtze River in central China's Hubei Province Wednesday,
June 11, 2003. Some 10 water diversion holes were opened to release water. The
water level of the Three Gorges Reservoir reached 135 meters (433 feet) on June
10. (AP Photo/Xinhua, Du Huaju)

Credits: Associated Press, XINHUA

[Image 3:
http://www.esa.int/export/esaCP/SEM4...html#subhead2]
Proba, Project for On Board Autonomy, demonstrates the potential and feasibility
of small satellites for advanced scientific and Earth observation missions.

Credits: ESA