Migration of the Ganga river and its implication o

Authors: U K Shukla N Janardhana Raju

Publish Date: 2008/10/10

Volume: 117, Issue: 4, Pages: 489-498

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Abstract

Borehole data reveals that during Late Quaternary the Ganga river was nonexistent in its present location near Varanasi Instead it was flowing further south towards peripheral craton Himalayan derived grey micaceous sands were being carried by southward flowing rivers beyond the present day water divide of Ganga and mixed with pink arkosic sand brought by northward flowing peninsular rivers Subsequently the Ganga shifted to its present position and got incised Near Varanasi the Ganga river is flowing along a NWSE tectonic lineament The migration of Ganga river is believed to have been in response to basin expansion caused due to Himalayan tectonics during Middle Pleistocene timesMultistoried sand bodies generated as a result of channel migration provide excellent aquifers confined by a thick zone of muddy sediments near the surface Good quality potable water is available at various levels below about 70 m depth in sandy aquifers Craton derived gravelly coarsetomedium grained sand forms the main aquifer zones of tens of meter thickness with enormous yield In contrast the shallow aquifers made up of recycled interfluve silt and sandy silt occur under unconfined conditions and show waterlevel fluctuation of a few meters during preand postmonsoon periods

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