Collapse of Indus Valley Civilization

Climate has long been implicated in the sudden and dramatic collapse of IVC. This article elaborates on that and offers new found evidence about the the fall. It also offers new insights into the present-day whereabouts of mystical Saraswati river.



Huge Ancient Civilization's Collapse Explained
Charles Choi, LiveScience Contributor

Date: 28 May 2012 Time: 10:01 PM ET
The mysterious fall of the largest of the world's earliest urban
civilizations nearly 4,000 years ago in what is now India, Pakistan,
Nepal and Bangladesh now appears to have a key culprit — ancient climate
change, researchers say.

Ancient Egypt and Mesopotamia may be the best known of the first great
urban cultures, but the largest was the Indus or Harappan civilization.
This culture once extended over more than 386,000 square miles (1
million square kilometers) across the plains of the Indus River from the Arabian Sea to
the Ganges, and at its peak may have accounted for 10 percent of the
world population. The civilization developed about 5,200 years ago, and
slowly disintegrated between 3,900 and 3,000 years ago — populations
largely abandoned cities, migrating toward the east.

"Antiquity knew about Egypt and Mesopotamia, but the Indus
civilization, which was bigger than these two, was completely forgotten
until the 1920s," said researcher Liviu Giosan, a geologist at Woods
Hole Oceanographic Institution in Massachusetts. "There are still many
things we don't know about them." [Photos: Life and Death of Ancient Urbanites]

Nearly a century ago, researchers began discovering numerous remains of
Harappan settlements along the Indus River and its tributaries, as well
as in a vast desert region at the border of India and Pakistan.
Evidence was uncovered for sophisticated cities, sea links with
Mesopotamia, internal trade routes, arts and crafts, and as-yet
undeciphered writing.

"They had cities ordered into grids, with exquisite plumbing, which was
not encountered again until the Romans," Giosan told LiveScience. "They
seem to have been a more democratic society than Mesopotamia and Egypt —
no large structures were built for important personalitiess like kings
or pharaohs."

Like their contemporaries in Egypt and Mesopotamia, the Harappans, who were named after one of their largest cities, lived next to rivers.

"Until now, speculations abounded about the links between this
mysterious ancient culture and its life-giving mighty rivers," Giosan
said.

Now Giosan and his colleagues have reconstructed the landscape of the plain and rivers where this long-forgotten civilization developed. Their findings now shed light on the enigmatic fate of this culture.

"Our research provides one of the clearest examples of climate change leading to the collapse of an entire civilization," Giosan said. [How Weather Changed History]

The researchers first analyzed satellite data of the landscape
influenced by the Indus and neighboring rivers. From 2003 to 2008, the
researchers then collected samples of sediment from the coast of the
Arabian Sea into the fertile irrigated valleys of Punjab and the
northern Thar Desert to determine the origins and ages of those
sediments and develop a timeline of landscape changes.

"It was challenging working in the desert — temperatures were over 110
degrees Fahrenheit all day long (43 degrees C)," Giosan recalled.

After collecting data on geological history, "we could reexamine what
we know about settlements, what crops people were planting and when, and
how both agriculture and settlement patterns changed," said researcher
Dorian Fuller, an archaeologist with University College London. "This
brought new insights into the process of eastward population shift, the
change towards many more small farming communities, and the decline of
cities during late Harappan times."

Some had suggested that the Harappan heartland received its waters from
a large glacier-fed Himalayan river, thought by some to be the
Sarasvati, a sacred river of Hindu mythology. However, the researchers found that only rivers fed by monsoon rains flowed through the region.

Previous studies suggest the Ghaggar, an intermittent river that flows
only during strong monsoons, may best approximate the location of the
Sarasvati. Archaeological evidence suggested the river, which dissipates
into the desert along the dried course of Hakra valley, was home to
intensive settlement during Harappan times.

"We think we settled a long controversy about the mythic Sarasvati River," Giosan said.

Initially, the monsoon-drenched rivers the researchers identified were
prone to devastating floods. Over time, monsoons weakened, enabling
agriculture and civilization to flourish along flood-fed riverbanks for
nearly 2,000 years.
"The insolation — the solar energy received by the Earth from the sun —
varies in cycles, which can impact monsoons," Giosan said. "In the last
10,000 years, the Northern Hemisphere had the highest insolation from
7,000 to 5,000 years ago, and since then insolation there decreased. All
climate on Earth is driven by the sun, and so the monsoons were
affected by the lower insolation, decreasing in force. This meant less
rain got into continental regions affected by monsoons over time." [50 Amazing Facts About Earth]

Eventually, these monsoon-based rivers held too little water and dried, making them unfavorable for civilization.

"The Harappans were an enterprising people taking advantage of a window
of opportunity — a kind of "Goldilocks civilization," Giosan said.

Eventually, over the course of centuries, Harappans apparently fled
along an escape route to the east toward the Ganges basin, where monsoon
rains remained reliable.

"We can envision that this eastern shift involved a change to more
localized forms of economy — smaller communities supported by local
rain-fed farming and dwindling streams," Fuller said. "This may have
produced smaller surpluses, and would not have supported large cities,
but would have been reliable."

This change would have spelled disaster for the cities of the Indus,
which were built on the large surpluses seen during the earlier, wetter
era. The dispersal of the population to the east would have meant there
was no longer a concentrated workforce to support urbanism.

"Cities collapsed, but smaller agricultural communities were
sustainable and flourished," Fuller said. "Many of the urban arts, such
as writing, faded away, but agriculture continued and actually
diversified."

These findings could help guide future archaeological explorations of the Indus civilization. Researchers can now better guess which settlements might have been more
significant, based on their relationships with rivers, Giosan said.

It remains uncertain how monsoons will react to modern climate change. "If we take the devastating floods that caused the largest humanitarian disaster in Pakistan's history as a sign of increased monsoon activity,
than this doesn't bode well for the region," Giosan said. "The region
has the largest irrigation scheme in the world, and all those dams and
channels would become obsolete in the face of the large floods an
increased monsoon would bring."

The scientists detailed their findings online May 28 in the journal Proceedings of the National Academy of Sciences.
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great article. thanks! it sounds very plausible! ghaggar is associated with sarasvati by many accounts. the post-harapan or the cemetery h culture that lay more inland and by which time a discernible fusion with or evolution of vedic hinduism had happened (cremation for one), might have introduced the harapan memory of a ghaggar or a sarasvati river to vedic lore (vedic hinduism is absent in harrapan culture -- as far as i know; contact might have been there with the proto-vedics but not a fusion of culture or the origin of vedic hinduism yet). all afaik!

The domain of this civilization is mind boggling and the time it lasted. Given that, it is surprising more research has not gone into it. Maybe with an ascendant India, we will see the gaps getting plugged.

Not likely Kris. Foreign academics and scholars have to go through huge bureaucratic hassles to get visas to India or Pakistan to study this area. I don't know if there are any subcontinent scholars that are even researching this. Even if they do, they are tainted by Hindutva ideology or Islamist ideology.
Many of the valuable sites have been plundered or destroyed by high population in this area. Political climate between India and Pakistan also poses a major roadblock to any research done in this region.

the extent of this civilization covered entire south asia to be honest. the civilization did not die -- it evolved or got assimilated. i recall one ruin discovered in bangladesh that was dated to be harappan or post-harappan (but not far out). yes, excavations and studies based on the excavations in south asia leave much to be desired.

Good article, thanks for posting. Until that script is deciphered, our knowledge of this vast civilization will remain rudimentary. I hope we will get to know soon what all those inscriptions mean.