A new scientific study published in the prestigious British journal Nature , has made a strong case that the Ghaggar-Hakra River which flows through modern-day India and Pakistan, was indeed a perennial river at the time period considered to be the peak of the Harappan civilisation.

Such a conclusion provides compelling support for the theory which identifies the Ghaggar-Hakra river with the ancient Sarasvati river mentioned in the Rigveda, which is said to be a perennial river as per details available in the scripture. A competing theory had been that the Ghaggar-Hakra river was always seasonal and the Harappans relied on monsoon rains.

The researchers looked at reconstructed sediments to understand changes in different historical periods which had taken place along a 300 km section of the river. They were able to establish that there were two major periods, the first one going back to roughly 78,000 to 18,000 BC and the other one from 7000-2500 BC, when the river flowed perennially.

The tributaries of the Sutlej are believed to have contributed in re-starting a perennial period for the river during the latter period. In their conclusion, the researchers link the end of the second perennial phase with the beginning of the decline of the Harappan civilisation, leading to the inhabitants from Ghaggar-Sarasvati valley leaving in search for more fertile soil.