Geography for GS Paper I is one of the highest-scoring sections in UPSC Prelims and Mains. The syllabus covers Indian Physical Geography comprehensively — from physiographic divisions and river systems to monsoon dynamics and soil types. This note covers the most exam-relevant concepts with crisp tables and MCQ practice.
India’s 6 Physiographic Divisions
| Region | Key Features |
|---|---|
| The Himalayan Mountains | 3 parallel ranges: Greater, Lesser, Siwalik; antecedent rivers |
| The Northern Plains | Khadar (new alluvium) vs Bhangar (old alluvium) |
| Peninsular Plateau | Oldest rock, Gondwana land; Deccan Trap; Black soil region |
| The Indian Desert | Thar Desert, Rajasthan; 12 cm annual rainfall |
| The Coastal Plains | East coast wider (delta forming); West coast narrower (estuaries) |
| The Islands | Andaman & Nicobar (Bay of Bengal) + Lakshadweep (Arabian Sea) |
River Systems
Himalayan Rivers (Perennial)
- Indus: Originates near Mansarovar Lake (Tibet) — antecedent river — Tributaries: Jhelum, Chenab, Ravi, Beas, Sutlej
- Ganga: Gangotri Glacier → world’s largest delta (Sundarbans) — Tributaries: Yamuna, Ghaghara, Gandak, Son
- Brahmaputra: Tibet (Tsangpo) → Majuli Island (world’s largest riverine island) in Assam
Peninsular Rivers (Seasonal)
- West-flowing (rift valleys): Narmada and Tapi — form estuaries (NOT deltas)
- East-flowing (deltas): Krishna, Godavari, Cauvery, Mahanadi — form deltas
Indian Monsoon
| Branch | Entry Point | Coverage |
|---|---|---|
| Arabian Sea Branch | Kerala coast (June 1) | Konkan, Western Ghats, Gujarat, NW India |
| Bay of Bengal Branch | NE India (June 1) | NE India → Bengal → UP |
El Niño = warming of central/eastern Pacific → weakens Indian monsoon (drought risk)
La Niña = cooling of Pacific → strengthens monsoon (excess rainfall risk)
Soils of India
| Soil Type | Region | Key Crop |
|---|---|---|
| Alluvial | Indo-Gangetic plains | Rice, wheat, sugarcane |
| Black (Regur) | Deccan Trap (Maharashtra, MP) | Cotton (self-ploughing) |
| Red and Yellow | Eastern Deccan, Odisha | Millets, groundnut |
| Laterite | Western Ghats, NE India, Kerala | Tea, coffee, cashew |
| Arid/Desert | Rajasthan, Gujarat | Bajra, pulses |
Important Rift Valleys in India
- Narmada Valley — graben between Vindhyas and Satpura
- Tapi Valley — parallel rift valley south of Narmada
Practice MCQs — UPSC Geography GS1
Practice Quiz — 10 UPSC-Style Questions
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Last updated: April 2026 | Civils Gyani — UPSC and State PCS preparation simplified