The lost saraswati river of northwestern Indian plains: Status and way forward

Abstract

Buried course of the desiccated river Saraswati/ Ghagghar-Hakara from Himalayan front to Arabian Sea through the plains of NW India has been in discussion and scientific investigations since ~140 years due to its importance in societal evolution and drainage disorganization. Its plains were inhabited by the Harappan/ Indus civilization (7000-1200BC) which collapsed around 4-3 ka BP. Views, both, in favor and against a relation between collapse of civilization and drying up of the Saraswati river exist. The palaeocourse of this river, causes and timing of its drying and reasons of civilization collapse still elude consensus. A large amount of new data generated in last two decades on surface, subsurface and chronological aspects of the Holocene deposits and archeology along the path of the Saraswati river has enhanced our understanding but the problem of defining its evolution through geological time is very complex. In this paper we critically examine the views on the link of the Saraswati paleochannel with the Sutlej towards west and Yamuna towards east as source for the perennial water supply. We also discuss the role of climate change and evaluate the role of active faults (Himalayan Frontal Trust and tear faults), basement structure (Delhi- Sargodha Ridge) and seismicity of the Haryana plains in context of the drainage reorganization as a possible cause of the drying up of the river. Systematic mapping of the entire palaeochannel course with generation of sedimentological and chronological data for the gap areas is suggested for understanding the evolution and demise of the Saraswati river.