The Yarlong Tsangpo,
Tibet's principal waterway, is the
upper half of India's great
Brahmaputra River. It is 2,900
kilometers ( 1,800 miles) long from
its source in western Tibet to its
mouth in Bangladesh. Tsangpo,
appropriately, means ' mighty'. The
Yarlong Tsangpo is the highest river
in the world, with an average
altitude of 4,000 meters ( 13,000
feet). It flows from west to east
parallel to the Himalayas Mountains
on their northern side.
Cascading from a high glacier,
gathering snow water, the Yarlong
Tsangpo enters a long, flat valley
above Shigatse as a typical braided
river winding among sandbanks. It
flows through temperate, fertile
central Tibet to Tsedang, where the
river nurtured Tibet's first
civilization. Along the 650
kilometers ( 400 miles) of its
middle reaches, a wide, navigable
channel, shifting with the seasons,
is plied by river craft: passenger
and cargo boats driven by converted
tractor engines; oblong, wooden
box-boats; and round coracles made
of yak hide and willow boughs.
In eastern Tibet, the river hooks
dramatically around the snow-capped
massif of Namcha Barwa, 7,756 meters
( 25,447 feet) high, and turns south
to India, where it is renamed
Brahmaputra ( son of Brahma, the
Creator). Here it turns west,
crossing the plain of Assam for
hundreds of miles, parallel to its
course through Tibet but in the
opposite direction and on the south
side of the Himalayas. Its waters
finally merge with those of the
Ganges in a vast delta flowing south
to the Bay of Bengal.
For a long time the Yarlong
Tsangpo's source remained a mystery
for Western geographers. An Indian
named Kinthup, one of the intrepid
surveyor -spies employed by the
British in the 1800s, first traced
it to the sacred Kailash Range of
western Tibet. In 1904-5, after
Colonel Younghusband had forced
Tibet into cordial relations with
British India, four British army
surveyors recorded their journey up
the river from Shigatse through
formidable terrain and hardships to
confirm its source in a huge glacier
southeast if Mt Kailash and Lake
Manasarovar.
Even more perplexing was its course
through the eastern Himalayas, once
people realized that the Yarlong
Tsangpo and the Brahmaputra were one
and the same river. They knew only
that it entered the mountains on the
north at 3,600 meters ( 12,000
feet), and that it dropped an
astounding 3,350 meters ( 11,000
feet) before emerging in India on
the south. Excited geographers
predicted an immense, hidden
waterfall. Explorers finished their
work in 1924 but found no falls
higher than nine meters ( 30 feet).
Instead they discovered a series of
incredible rapids and cascades,
whose violent waters raced ten
meters( yards) per second through
towering cliffs and gorges, eroding
the riverbed deeper and deeper into
the limestone rock.
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