A
research paper authored by R. Rajbhandari and others and published
recently in the journal, Climate Dynamics predicts that the 1.1
million sq. km basin of Indus river, shared by India, Pakistan,
Afghanistan and China, is expected to warm significantly and
progressively, with average temperatures set to increase by around 4
degrees C by 2080. The paper titled as “ Projected
changes in climate over the Indus river basin using a high resolution
regional climate model (PRECIS)”
says that the resulting warmer winters in the plains, quicker snow
melt in the basin's northern highlands (comprising parts of the Hindu
Kush, Karakorum, and Himalayas) and more frequent flash floods at the
foothills can be expected over the next seven decades, altering the
basin’s hydrology. Winter in the Indus basin on average could be
warmer by 3.9 to 5.1 degrees C, and summers by 3.4 to 4.6 degrees C.
The
paper adds that by 2080, the number of rainy days over the basin will
increase and the intensity of rainfall is likely to rise in the
foothills of the Hindukush and other highlands — an area that is
already prone to flash floods. Northern highlands could get hotter,
and snow and glacier melt likely to hasten. The most affected will
be people with least adaptation capacity. Farmers may be left with no
choice but to change their cropping patterns, perhaps even their
crops.
We
might as well assume that the report gives us a fairly true picture
of what is going to happen in next seven decades in the Indus basin
as the report has been published by well qualified experts in the
field. However, it is entirely possible that many people are likely
to get alarmed by these predictions, but any one, who knows about
the long term weather history of the region, would find nothing
abnormal or extraordinary in these predictions as this is what has
been happening here for last 10000 years and that is why Indus
civilization flourished here once only to get extinguished later.
Another
study about Indus basin, this time about the past history of the
Indus basin, was published on 28th May 2012 in the Proceedings of
the National Academy of Sciences and lead authored by Liviu Giosan, a
geologist with Woods Hole Oceanographic Institution (WHOI). This
report claimed to have found the answers to the question as to why
once flourishing Indus civilization had suddenly collapsed. The study
was done from 2003 to 2008 from the Arabian Sea coast to the fertile
valleys of Punjab and the northern Thar Desert in Pakistan. Over this
period, Liviu Giosan's team of 15 international experts, which
Included Prof Ronojoy Adhikari of the Institute of Mathematical
Sciences, Chennai, studied satellite photos and topographic data
collected by the Shuttle Radar Topography Mission. From this data the
team created digital maps of landforms in the basins of Indus and
other rivers. This analytical work was then confirmed with help of
field work in the area, consisting of drilling, taking core samples
and digging deep trenches to study cross-sectional views.
With
this data, it was possible for Giosan's team to reconstruct the
landscape of the plains habitated by Indus civilization 5200 years
ago (3100 BCE), how the great cities like Harrapa were built and the
gradual disintegration of the plains that took place in a period 3900
to 3000 years ago (1800 BCE- 900 BCE). Armed with this information,
Giosan's team was able to draw following conclusions.
Spread
over 1 million square Km. From Arabian sea coast to Ganges, the Indus
civilization was the largest but least known civilization of the
first urban cultures of the world. This civilization, like other
great civilizations of Egypt and Mesopotamia also flourished next to
some great rivers. However, remains of this vast human settlement are
found even in vast desert areas far from any rivers today. This south
Asian culture, which might have contained one tenths of world's
population in those days, was all forgotten till 1920. Subsequent
archeological research has unearthed a sophisticated urban culture
with myriad internal trade routes and well-established sea links with
Mesopotamia, standards for building construction, sanitation systems,
arts and crafts, and a yet-to-be deciphered writing system.
Before
this massive human habitation had settled in, for previous ten
thousand years, wildly flowing river Indus and its tributaries had
deposited rich soil sediments on stretches between them. The monsoon
rains that brought floods to the rivers, actually started declining
with time. Weakened monsoon rains and reduced run-off from the
mountains, helped in taming the wild Indus and its Himalayan
tributaries, so that agriculture along their banks became possible.
As a result, human settlements bloomed along the Indus and its
tributaries from the coast to the foothills of the Himalayas. The
weakened monsoon rains created a window of about 2000 years in which
Harappans took advantage of the opportunity and a great civilization
arose on the banks of Indus and tributaries. Indus civilization, was
built on bumper crop surpluses along the Indus and the Ghaggar-Hakra
rivers from this earlier wetter era and required a huge concentration
of workforce. This workforce requirement developed into great urban
centers like Mohenjodaro and Harrapa.
As
monsoon weakened progressively, this window of prosperity began
closing and widespread aridification of the lands, where plenty of
water was available earlier, drove the Harappans eastwards east or
towards Ganga river by 1500 BCE, where monsoon rains remained
reliable. The economic structure in the east with local rain-fed
farming and dwindling streams could only support smaller agricultural
surpluses and could not support large cities of Indus civilization.
The cities collapsed and with them the urban arts such as writing.
The population in Ganga basin now dispersed in small agricultural
communities, survived and even diversified.
Readers
would be immediately able the conclude that changing weather patterns
have been more of a norm in the Indus basis as seen from this study
of 10000 years and the inhabitants here have been continuously
adopting their crop patterns and way of life, to the vagaries of
nature or to be more specific depending upon the monsoon and the
weather.
We can
safely assume therefore that even if the weather pattern changes as
per the predictions of this research paper, there seems to be little
cause of worry with cultivators cultivating the lands in the Indus
basin with appropriate responses.
23rd
June 2014
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