The Himalayan and Peninsular drainage systems differ not just in age and origin but in their hydrology and economic value to India. Examine.
Subtopic: Geography · Economic and Resource Geography — Rivers and Water
How to structure your answer
Introduction: India’s rivers fall into two systems shaped by the country’s split physiography — young Himalayas in the north, ancient Deccan plateau in the south.
Body — three dimensions: (1) Origin and age: Himalayan rivers are antecedent, predating Himalayan uplift (Indus, Brahmaputra cut transverse gorges); Peninsular rivers (Godavari, Krishna, Cauvery) flow on a pre-Cambrian plateau. (2) Hydrology: Himalayan rivers are perennial — snowmelt plus monsoon; Peninsular are seasonal, monsoon-fed, with deep gradient-graded courses. (3) Economic value: Himalayan rivers supply 80% of India’s usable surface water, support Indo-Gangetic agriculture, hydropower potential; Peninsular rivers support irrigation in deltas (Krishna-Godavari, Cauvery), inland navigation limited.
Conclusion: The two drainage systems sit behind India’s most political river disputes — Indus Waters Treaty (1960), Cauvery Tribunal, Krishna allocation — because their hydrology defines who has water to share.
Written within the word limit
142 words · target 150 words · 9 min
Introduction: India's two river systems were shaped by a split physiography — the young Himalayas in the north and the Pre-Cambrian Deccan plateau in the south.
Body: Himalayan rivers (Indus, Ganga, Brahmaputra) are antecedent, cutting transverse gorges older than the mountains they pierce — the Brahmaputra's Great Bend at Namcha Barwa is the textbook case. Peninsular rivers (Godavari, the longest at 1,465 km, Krishna, Cauvery) flow over a stable, gradient-graded crustal block. Hydrologically, Himalayan rivers are perennial — fed by snowmelt and monsoon — and supply about 80 per cent of India's usable surface water, sustaining Indo-Gangetic agriculture and Bhakra-Nangal hydropower on the Sutlej. Peninsular rivers are monsoon-fed and seasonal; Narmada and Tapi flow west through rift valleys; the Krishna-Godavari and Cauvery deltas anchor southern irrigation.
Conclusion: These hydrological asymmetries explain India's sharpest water disputes — the Indus Waters Treaty (1960), the Cauvery Tribunal award (2007), and the contested Krishna allocation.
What an examiner expects to see
- Himalayan rivers — Indus, Ganga, Brahmaputra systems
- Antecedent drainage — rivers older than mountains they cut
- Peninsular rivers — Godavari (longest peninsular, 1,465 km), Krishna, Cauvery, Narmada, Tapi
- Westward-flowing peninsular rivers: Narmada, Tapi, in rift valleys
- Indus Waters Treaty 1960 with Pakistan
- Cauvery Water Disputes Tribunal, award 2007
- Krishna and Godavari delta agriculture
- Himalayan rivers supply about 80% of India’s usable surface water
Concrete cases, schemes and judgments
- Brahmaputra’s Great Bend at Namcha Barwa
- Godavari — ‘Dakshina Ganga’
- Narmada and Tapi in rift valleys flowing west
- Sardar Sarovar Project on Narmada
- Bhakra-Nangal on Sutlej