Anindya Sarkar, professor of geology and isotope geochemistry at IIT, Kharagpur, was lead researcher of a recent paper published in the Journal of Quaternary Science, on how Dholavira, an Indus Valley Civilisation (IVC) site, holds important lessons for dealing with climate change. The site was excavated by RS Bisht in the 1990s. Sarkar explains his study to Avijit Ghosh | Read the full interview in the Times of India here >>
[…] Dholavira is the fifth largest site of the Indus Valley Civilization. It is also the largest excavated site in India? Yet it is lesser known than say, Kalibangan. Why?
I do not know if such a comparison can be made. Kalibangan is located at southern bank of the presently dried river Ghaggar in Rajasthan and characterised by its unique fire altars and one of the world’s earliest ploughed field. But the features of Kalibangan and Dholavira are similar, similar town planning like citadel, lower town etc., and roads which had precision width. The timing is also almost similar from 3500 BCE to 1700 BCE after which both the cities collapsed. The only thing about Kalibangan is it was dated very extensively by archaeologists and its different phases were very well constrained by carbon dating. But after our work, Dholavira archaeological periods are also now on very strong ground in terms of its chronology. Dholavira is lesser known probably due to its remote location in the salt desert and also it was not studied until recently by using modern scientific techniques. In any case both were unique Harappan metropolis exhibiting very advanced city planning not found even in its counterparts in West Asia.
What caused the demise of Dholavira?
From the Later part of Mature Harappan time, i.e. from ~2400 year BCE the expansion of the city at Dholavira slowed down or even ceased until 2300 year BCE with an abrupt decline between 2300 and 2000 year BCE manifested by degeneration of architecture, craftsmanship, and material culture. They were unable to maintain the city; resources were scarce and water reservoirs were no longer in use. Also the site was deserted for few centuries. During the last Stage the city had disappeared, along with the classical Harappan elements and what remained had no resemblance to the Harappan culture. In a sense, it was an attempt to resettle at Dholavira but in a very basic way when probably the pastoralism re‐appeared who had no connection with the developed Harappan culture. Even this was for a very short period and the site was finally deserted. We feel the demise was connected to climate change. We analysed high resolution oxygen isotopes in mollusc shells Terebralia palustris. These are found aplenty in Dholavira, many of them are finely cut by human and were being consumed for food by the Dholavirans. These molluscs typically grow in mangrove suggesting that the people were harvesting them from nearby mangroves. The isotopes tell about the sources and the seasonality of water in which these animals grew. Surprisingly when we analysed the Early to Mature Harappan molluscs (2700 year BCE old) it looked that they grew in a water that is only possible if glacial meltwater mixes in the mangrove. The seasonality was high. This clearly suggested that a glacier fed river was debouching in the Rann of Kutch. But then isotopes in the molluscs from terminal part of mature to late Harappan from 2300 to 2100 years BCE indicated that the glacial contribution disappeared and seasonality reduced. This is the time that exactly coincides with the decadence and fall of the city of Dholavira as indicated by the archaeological evidence and the onset of the newly proposed Meghalayan stage (a divison of geological time) suggested last year by an international body of geologists and stratigraphers when a drought occurred across the globe. We could immediately make the connection. The monsoon was anyway declining. Dholavirans adopted excellent water conservation strategy by building dams, reservoirs and pipelines. But came the apocalypse of few centuries of Meghalayan drought and the whole city collapsed. The collapse of Harappan Dholavira was near‐synchronous to the decline at all the Harappan sites in India like Kalibangan, Lothal, Rakhigarhi as well as Mesopotamia, and the Old Kingdom of Egypt and China.
Your paper says, Dholavira presents a classic case for understanding how climate change can increase future drought risk across much of the sub‐tropics and mid‐latitudes? […]
The final blow to the Harappans, however, came when a global mega‐drought spread over over 2‐3 centuries hit them and they could no longer cope up. And as I said it was collapse of all the major ancient cityscapes across the globe. This seems like a fiction but it teaches us two important lessons. One is we must learn quickly how to cope up with the reduced monsoon and water deficit due to climate change specially our agriculture. Second if we do not learn then a catastrophe is waiting for us. The Dholavirans sustained for 1700 years and the modern civilisation is just about 200 years (if you consider industrial revolution). It is hard to tell what will happen after another 1500 years‐ will mankind survive or perish? […]
Source: ‘Dholavira is the most spectacular Indus Valley site in India; its demise was connected to climate change’
Date visited: 27 April 2020
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Publications on the above issues may be found here (title descriptions and libraries):
- Ashoka Trust (Atree.org)
- Biodiversity Act | Biodiversity hotspot
- Ecology and environment
- Eco tourism | Tourism | Wildlife tourism
- Environmental history and what makes for a civilization – Romila Thapar
- Equations blog
- Forest Rights Act (FRA)
- Indigenous knowledge systems
- Information provided by Indian government agencies and other organizations (FAQ)
- Man animal conflict
- Nature and wildlife | Crocodile | Elephant | Tiger | Trees
- When your neighbour is a tiger: PARI’s tales from tiger territory
- Revival of traditions
- Sacred grove
- Success story
- Western Ghats – tribal heritage & ecology
- Wildlife tourism
Research the above issues with the help of Shodhganga: A reservoir of theses from universities all over India, made available under Open Access >>