The Vedic description of the goddess Sarasvati as a mighty river, and the Vedic and Puranic statements about the drying-up and diving-under of the Sarasvati, have been used by some as a reference point for a revised dating of the Vedic culture. Some see these descriptions as a mighty river as evidence for an earlier dating of the Rig Veda, identifying the Vedic culture with the Harappan culture, which flourished at the time that the Gaggar-Hakra hadn't dried up, and rejecting the Indo-Aryan migrations theory, which postulates a migration at 1500 BCE.