An Encyclopaedia of Indian Archaeology v1.c14.s10.t2.3

v1.c14.s10.t2.3

Rivers do not change their courses unless some strong geophysical changes or disturbances or climatic oscillations take place. Since such phenomena did not take place in the stable mass of peninsular India in the post-Pleistocene [9.8.4] period, one rarely comes across a total abandonment of a major river valley at any stage of the sedentary cultures. If a site was abandoned it was mainly due to socio-economic [or political] reasons. But the situation in the n. plains was much different. Explorations and excavations conducted in the Indo-Ganga divide by Ghosh, 1952; Raikes, 1968, and others clearly show that rivers like the Ghaggar (SARASVATĪ) Chautang (DṚṢADVATĪ) and YAMUNĀ changed their courses several times, directly affecting the settlements. The field investigations made by drilling the land at three places in the Ghaggar bed near KALIBANGAN and the geomorphological observations made in the field by studying detailed maps Raikes came to the conclusion that about 6000-5000 B.C. there were only two river systems—the Indus and the Ganga. The Yamuna as a tributary of the Ganga was where it is today. Then about 2500 B.C. the Yamuna shifted its course w. wards and joined the Ghaggar. Incidentally at that time the SUTLEJ also discharged its water into the Ghaggar. This mighty river then flowed through the Bahawalpur region and joined the Indus lower down the present-day junction of the Chenab and Indus. In its valley Harappa [4.9] and pre-Harappa [4.18] (SOTHI) sites have been located by Stein, 1942, and Ghosh, 1952. But these sites seem to have been abandoned around 1700 B.C. Raikes feels that this took place because at that time the Yamuna shifted back to its original channel. Singh [7.4, with references], on the basis of his findings on the pollens collected in the Rajasthan lakes, has come to the conclusion that at that time rainfall decreased considerably and desiccation of land set in. For about 600 years hardly any population seems to have lived permanently in the Ghaggar valley. But then suddenly due to coriolis force (deflection force due to the earth's rotation) the Yamuna witnessed its right bank ovulsion somewhere near Indri. About 1100 B.C. once again the Yamuna started flowing w.wards and supporting the Ghaggar, albeit with less water. The Ghaggar system had now narrower water-channels than those it had in the Harappa times. A new set of people, the users of the PGW [4.15], now occupied it. Their sites are therefore found located within the older bed of the Ghaggar but along the new banks of the channels. In the Ghaggar valley no Harappa mound was ever reoccupied by the PGW people. Up to about 500 B.C. the situation remained the same when the Yamuna once again came back to its present channel. Consequently the PGW people also seem to have moved out of the Ghaggar valley. History repeated itself in *c.* 100 B.C. and the Yamuna was once again captured by the Ghaggar. We have a number of early historical sites of the RANG MAHAL culture [4.18.2] along the rejuvenated channel in the Ghaggar. These again were abandoned around A.D. 500, possibly due to the Yamuna going once again to its old e. channel.