Sarasvati is the most celebrated river in the Rigveda on whose banks numerous hymns were composed. While many rivers are merely named, Sarasvati is described at length in the old Mandalas. It is called a mighty river which raises foam, makes waves , roars, cuts its banks and finally flows into a samudra. (Samudra literally means a water body. Its translation as ocean is a recent phenomenon.) In its course, it receives many tributaries which are called its daughters. There are other independent rivers in the area which are called its sisters.
This is the Sarasvati of the Old Mandalas. The tenth Mandala, unanimously agreed to be a later work contains River Hymn which mentions Ganga, Yamuna, Sarasvati in sequence, but only in passing. The pride of place in the hymn belongs to Indus. All adjectives and superlatives earlier applied to Sarasvati are now transferred to Indus. It is clear from context that the Sarasvati of the tenth Mandala cannot be the ‘naditama’ Sarasvati of the old Mandalas. There is a consensus among Vedic scholars that the Sarasvati of the last Mandala should be identified with the present-day Ghaggar lying between Satluj and Yamuna. It would seem that it is the phrase Ganga, Yamuna, Sarasvati that gave rise to the later legend that Sarasvati invisibly joins Ganga and Yamuna at Prayag Raj. Note that the Sarasvati of the old Mandalas as well as that of the tenth Mandala can in no way be reconciled with the Puranic description of invisible Sarasvati associated with Ganga and Yamuna.
When the term Rigvedic Sarasvati is used , the Sarasvati of old mandalas is meant. Even though Rigvedic hymns have been preserved over millennia, the question of river identification never arose. The question was taken up by European Indologists
The Norwegian scholar Christian Lassen suggested in 1858 that the Rigvedic Sarasvati be identified with Old Ghaggar. In 1891, in his English translation of the Rigveda, Max Muller asserted that at the time of the composition of the hymns, Ghaggar was a large river. He however was careful to admit that ‘it may not be possible to determined by geological evidence the time of the changes which modified the southern area of the Punjab and caused the Sarasvati to disappear in the desert‘. Max Muller had to resort to speculation because in his time geology was scientifically and technologically not advanced enough to answer questions about chronology. A hundred years later there is no need to indulge in idle conjecturing because we can answer the question unambiguously.
Rainwater fed Ghaggar rises in the Shivaliks and collects a number of tributaries. At present Ghaggar does not reach the sea but loses its way in the desert sands. There can be no doubt that at some epoch in the past, both Satluj and Yamuna flowed into Ghaggar and the combined river emptied into the sea. In this high-tech era, it has become common to draw attention to satellite imagery and remote sensing to make the point that Satluj and Yamuna gradually moved away from Ghaggar to reach their present state. It is important to note that the finding is more than a century old; it was arrived at through actual field work by British Indian officials. The key question is this: when did Ghaggar reach its present sorry state? Possibility exists that the shifting of Satluj and Yamuna took place 10000 or even 10000 years ago, that is much before the Rigvedic time. I have seen chronologies being extracted from remote sensing data. What is astonishing about many such technical reports is that they quote sacred texts. Geology is older than religion or religious texts. Interpretation of scientific evidence cannot depend on scriptures. Science should arrive at its findings from internal findings. These findings in turn should be used to constrain literary theories.
Remote sensing data requires the help of mathematical modelling which can raise suspicions. There is no reason to depend on indirect methods when the hydrological history of the Ghaggar system can be ascertained in a straightforward manner by collecting samples from dry river beds and paleo-channels and analysing them in the lab. To be credible this research should be carried out by an international team in a scientifically rigorous and open-ended manner.
Even if for the sake of argument it is conceded that in Rigvedic time, both Satluj and Yamuna flowed into Ghaggar, Ghaggar would still not conform to Rigvedic description. Waters from the snow-fed Satluj and Yamuna would strengthen lower Ghaggar. Upper Ghaggar would still be as puny as it is today. By no stretch of imagination can the puny rain-fed Shivalik stream that upper Ghaggar is be called foremost of rivers when mighty glacier-fed Satluj and Yamuna lie tin the neighbourhood.
Let us take the help of modern science to answer important questions on ancient Indian history. Till the time answers are obtained to everybody’s satisfaction, it would be prudent to keep one’s mind open.