For the first time the researchers have connected the decay of Harappan city Dholavira to the disappearance of a Himalayan snow-fed river which once flowed in the Rann of Kutch.
They have reconstructed the dots between the growth and fall of Dholavira, the most spectacular and largest excavated Harappan city in India located in the Rann with this river which resembles the mythical Himalayan river Saraswati. The study has been published online in Wiley Journal of Quaternary Science.
Previous studies focused on finding out the river courses, its connection to climate and civilization in areas far away from these ancient cities. But this research team from IIT Kharagpur, Archaeological Survey of India, Deccan College PGRI Pune, Physical research laboratory, and Department of Culture, Gujarat, dated archaeological remains from all the stages and also inferred climate shifts through time which led to the rise and fall of the Harappan city.
“Our data suggest that prolific mangroves grew around the Rann and distributaries of Indus or other palaeochannels dumped water in the Rann near southern margin of Thar Desert. This is the first direct evidence of glacial fed rivers quite like the supposedly mythological Saraswati, in the vicinity of Rann” said IIT Kharagpur’s Anindya Sarkar who led the research.
Ravi Bhushan and Navin Jugal from PRL, Ahmedabad dated the carbonates from human bangles, fish otolith and molluscan shells by accelerator mass spectrometer and found that the site was occupied from around 5500 years back or the pre-Harappan period to around 3800 years before present or late Harappan period.
What does the study state?
The Dholavirans, probably the original inhabitants in the region, had a fairly advanced level of culture even at its earliest stage. They built a sprawling city and survived for nearly 1700 years by adopting water conservation suggest the researchers.
The study indicates that the city expanded till 4400 years followed by an abrupt decline nearly 4000 years back, onset of the newly proposed Meghalayan geological stage, according to RS Bisht and YS Rawat from the ASI who originally excavated the site based on degeneration of architecture, craftsmanship and material culture.
“Though the Dholavirans adopted excellent water conservation strategy by building dams, reservoirs and pipelines, but were pushed to the limit by a catastrophic Meghalayan mega-drought collapsing the city. Indeed Dholavira presents a classic case for understanding how climate change can increase future drought risk as predicted by the IPCC working group” added Anindya Sarkar.
The lead author of the paper and a PhD student at IIT Kharagpur, Torsa Sengupta, said, “The early to Mature Harappan snail isotopes suggested that the mangrove was fed by Glacier River debouching in the Rann of Kutch. However, during late Harappan period the meltwater contribution and seasonality reduced coinciding with the fall of Dholavira.”
The research indicates that the collapse of Harappan Dholavira was near-synchronous to the decline at all the Harappan sites in India as well as societal collapse of Mesopotamia, Greece, China and the Old Kingdom of Egypt.
“This was due to the disruption of the westerlies and Indian and East Asian monsoons at 4200 years back leading to a nearly 250 year widespread drought. The collapse of Dholavira is very important evidence for reconstructing these global archaeological and climate events” said Mike Walker of University of Wales who discovered the Meghalayan Stage.
Arati Deshpande Mukherjee of Deccan College corroborated the climate evidence coming from high resolution oxygen isotopes in snail shells Terebralia palustris which typically grow in mangroves and was a source of food for the Dholavirans.
Interestingly, the existence or the lack of it has been a serious issue among sections of Indian historians for long. The former Union Minister of HRD and S&T, Murli Manohar Joshi, had initiated a project to study the river Saraswati in the late 1990s.