Two large floods annihilated several medieval Indian dynasties: study

KOLKATA: Two large floods caused by anomalies in monsoon patterns, which flooded large parts of the subcontinent approximately 800 and 700 years ago, could have eliminated the powerful dynasties in what is now known as India.

Surprising evidence of this has been discovered by a group of geology experts from IIT Kharagpur.

The group's findings, published in Elsevier, a prestigious Dutch magazine specializing in scientific, technical and medical content, have surprised historians and archaeologists.

The findings are based on years of study of oxygen isotopes in ancient stalagmites of the Wah Shikar caves. Oxygen isotopes are indicators of the traces left by precipitation or precipitation over a period of time, called time slippage by scientists.

The stalagmites are thousands of years old, but the group studied the history of rainfall for just over 900 years, between 1100 AD and 2012 AD, considering the fact that three important climatic events took place in the subcontinent during this phase.

The three main climatic changes that took place during this time are: Medieval climatic anomaly that took place between 1100AD-1300AD; the Little Ice Age that is approximately between 1300AD-1750AD; and the current warm period between 1750 AD to the present. The two main floods that have been indicated by geologists occurred approximately around 1210 AD and 1320 AD respectively, depending on the intensity of the rainfall marks in the stalagmites.

“It rained a lot for months, flooding large parts of what we know today as India. The floods were so high and severe that they not only destroyed the dynasties, killed ordinary people and forced them to leave their homes and become nomads in search of high ground, but also ruined the agrarian economy of the time, said Anil Gupta , the main scientist of the group.

Among the dynasties that ended around this time were Sena in, Solanki in the west and Paramar, Yadav and Pandyan in the south. We are working closely with historians and archaeologists so that we can corroborate the details of our period with theirs, Gupta told TOI.

Stalagmites were drilled at intervals of every half millimeter, following a dating process in which every half millimeter represents two years of real-time experience of the rock. The perforated portions have traces of rain engraved on them and then they were passed through the uranium-thorium time series that dates to reach the correct conclusion about the time of precipitation.

The two floods were never recorded in history and, therefore, the uniqueness of the finding, Gupta said. “There is little documented history during the thirteenth and fourteenth centuries that has reached us. Most of the time, wars were considered the reasons for the fall, but the discovery of the two mega floods will now add better value to the previous explanations. One can allude to the theory of the flood that perhaps ended with it.

The group has also indicated that flooding could also have occurred in China, and could have been the cause of the area's fall. Elsevier's article notes that from 1750 AD onwards, the subcontinent has experienced severe rainfall and monsoon fads have seen the worst extremes during this time. “Stalagmites have indicated 12 floods and 12 droughts during this phase. However, this phase of history is relatively better documented, thanks to the arrival of the British and we can easily corroborate our findings with what has reached us in history, Gupta said.

Scholars who deal with ancient Indian history feel that these findings will be very useful in identifying the antiquities of known events. “Little by little, the gap between humanities and technology is decreasing. We have very little documentation in regards to the pre-British era. Naturally, it is difficult to reach scientific conclusions about many events in Indian history. The antiquities that historians have tried to establish often have also been questioned for lack of evidence. Fortunately, IIT Kharagpur has been constantly helping with this. Their findings have recently helped delay the beginning of the Indus civilization by at least 2,000 years. Flood theory will similarly help put certain endings and migrations into perspective, said historian Ramkrishna Chatterjee, secretary of publications for the Asian Society.

Historian Arun Bandyopadhyay also seemed excited. He felt that such a geological study of Indian history was necessary for a long time. In the past, a similar climatological study of famines was carried out in the European context. It is encouraging to know that IIT Kharagpur geologists are applying similar scientific methods to discover important geological events that will add a new perspective to the history of India, Bandyopadhyay said.