|
|
|
Two senior scientists at the Bhabha Atomic Research Centre, Dr S M
Rao and Dr K M Kulkarni, claim to have traced the course of the
River Saraswati, which, according to legend, was lost in the Thar
desert of Rajasthan.
According to Rao and Kulkarni, the river, originating from the same
source as the Sutlej, flows underground through northern Rajasthan,
Bhawalpur, and Sind in Pakistan till it empties out in the Rann of
Kutch.
The duo, working in tandem with the Ground Water Department of
Rajasthan and the Central Arid Zone Research Institute, have traced
the course of the river using Landsat imagery and isotope-tracing
techniques.
"We discovered many underground fresh-water channels with low
levels of tritium, a naturally occurring radioactive isotope, which
helps to establish the age of the water," said Rao, who heads the
isotope division at BARC, Mumbai.
In the case of the channels Rao and Kulkarni studied at Ghantiali,
Kuriaberi and Nathurakuan in Jaisalmer district, the water was
found to be more than 8,000 years old. "This was a pluvial episode
with plenty of rainfall in this area. The episodes of aridity
began much later," says Rao.
This is borne out by ancient accounts of the river. The Saraswati
is mentioned in the Vedas as a mighty river, originating in the
Himalayas and flowing westwards through Rajasthan. But the
Mahabharata, which was written much later (around 1,000 BC),
reports a once-mighty river that was drying up.
In Rajasthan, the Saraswati is more than a water source - the river
is revered as Vanaspati Devi. The search for the lost river has
drawn scholars and royal patronage for centuries. "Our study will
have an emotional as well as historic significance for
Rajasthanis," says Rao.
But Rao and his colleagues will have to hurry up as work on the
second phase of the Indira Gandhi Canal has begun and infusion of
fresh water is likely to disturb the underground channels.
Rao's work has also been made more difficult by the fact that the
Saraswati has changed her course to the west at least five times.
An earlier study linked the ancient Saraswati to the present-day
Ghaggar river while other scholars have suggested that the Sutlej
at one point flowed into the Saraswati, later shifting westwards to
join the Indus system. Another hypothesis suggests that the Indus
itself could at one point have been a tributary of this mighty
river, which, according to Vedic sources, was bigger than the
Ganga.
The old underground channels of the Yamuna have also been traced to
Saraswati's system. The Yamuna probably flowed into the Saraswati
before joining the Ganga through the Chambal.
The channel of the Saraswati, with a constant width of six to eight
metres, is traceable through Shtarana in Punjab, up to Marot in
Pakistan, through northern Rajasthan, and is likely to have
extended to the Hakra-Nara bed around the Rann of Kutch, which then
emptied out into the Rann.
Rao's research is supported by Landsat images which show a narrow
strip of vegetation along the course supported by groundwater while
the surrounding areas continue to be dry.
The research has practical use for the parched state. "The
freshwater channels can be tapped for domestic use, reducing the
hardship faced by the people during dry months," says Rao. The
water channels pass right through the heart of the Rajasthani
desert.
 |
||
|
||
|
||
