Sarkari RiseLogin

Physical Geography / Palaeo-hydrology of Indian Rivers — UPSC Mains Model Answer

Geography · UPSC CSE
Question: Palaeo-hydrology of Indian rivers — evidence for ancient river course shifts between the Indus and Ganga systems during the Pleistocene

Introduction

The Pleistocene-era reorganisation of the Indian subcontinent's river systems — particularly the hypothesised linkages between the Yamuna, Sutlej, and the Saraswati — carries profound implications for understanding regional geomorphology, biodiversity, and even early human settlement patterns.

Body

1. Biological Evidence: Shared Dolphin Species

The presence of the same species of freshwater dolphin (Platanista) in both the Indus and Ganga river systems is a compelling biogeographic indicator. Shared fauna across presently separated drainage basins strongly suggests past hydrological connectivity, as such species cannot migrate overland. This biological evidence directly supports the assertion of ancient river capture or course diversion.

2. Textual Evidence: Rigvedic Nadi-Sukta

The Nadi-Sukta hymn in the Rigveda lists rivers in a geographic sequence that places the Yamuna alongside rivers of the northwestern (Indus) system. Scholars interpret this as a cultural memory of a period when these rivers were hydrologically connected, lending indirect textual support to the palaeo-hydrological hypothesis.

3. Geomorphological Investigations

Geological and geomorphological surveys of the Sutlej and Yamuna valleys have identified wind gaps, abandoned channels, and alluvial terraces consistent with river capture events. These landform signatures indicate that one or both rivers once followed substantially different courses, corroborating the Pleistocene diversion hypothesis.

4. Robert Bruce Foote's Explorations

Robert Bruce Foote, a pioneering geologist with the Geological Survey of India, conducted fieldwork across peninsular and northern India. However, his documented contributions focused primarily on Palaeolithic archaeology rather than systematic exploration of the Sutlej-Yamuna drainage divide, making this option the weakest evidentiary basis among those listed.

Conclusion

Palaeo-hydrological reconstruction relies on converging evidence — biological, textual, and geomorphological. Distinguishing robust scientific evidence from speculative or misattributed sources remains essential for accurate understanding of India's ancient drainage evolution.

Word count: 258

Get your own answer evaluated by AI

GS Answer Coach grades your Mains answer on structure, substance, and conclusion — in under a minute.

Open GS Answer CoachPractice Physical Geography / Palaeo-hydrology of Indian Rivers PYQs →

More Geography model answers

Astronomy / Stellar Evolution
Climate
Climate and Monsoon
Climatology / Atmosphere
Climatology / Atmosphere Structure
Climatology / Atmospheric Forces

Daily AI coaching for UPSC Mains

Essay Coach · GS Answer Coach · Cutoff Planner · 500+ Mains PYQs — free to sign up.

Sign up freeSee UPSC Pro