Indian Geography – Advanced Study Notes for Kerala PSC
(General Awareness & Current Affairs – MIT‑Level Treatment)
Table of Contents
| # | Section | Sub‑topics |
|---|---|---|
| 1 | Foundations | 1.1 Geomorphological Basis |
| 2 | Physical Geography | 2.1 Continental Crust & Tectonics 2.2 Mountain Systems 2.3 Plateaus, Basins, and Plains 2.4 Coastal Morphology 2.5 Hydrography |
| 3 | Climatology | 3.1 Monsoon Dynamics 3.2 Climate Zones (Köppen–Geiger) 3.3 Climate Change Impacts |
| 4 | Human Geography | 4.1 Population Distribution & Density 4.2 Urbanization & Megacities 4.3 Economic Geography |
| 5 | Resources & Economy | 5.1 Mineral Resources 5.2 Energy & Oil & Gas 5.3 Agriculture & Fisheries |
| 6 | Environmental Challenges | 6.1 Erosion & Deforestation 6.2 Water Scarcity & Groundwater Depletion 6.3 Biodiversity & Conservation |
| 7 | Edge Cases & Anomalies | 7.1 Disputed Territories & Enclaves 7.2 Unique Biomes (e.g., Western Ghats, Eastern Himalayas) 7.3 Geographical Oddities (e.g., Kanyakumari, Trishna Island) |
| 8 | Current Affairs Highlights | 8.1 Recent Land‑Use Policy Changes 8.2 Infrastructure Projects (e.g., NITI Aayog Green Plan) 8.3 Climate Agreements & National Initiatives |
| 9 | Challenging Problem | 9.1 Problem Statement & Solution Sketch |
| 10 | Key Take‑aways | 10.1 Quick Facts & Mnemonics |
1. Foundations
1.1 Geomorphological Basis
- Plate Tectonics: India sits on the Indian Plate, which collided with the Eurasian Plate ~50–55 Ma, forming the Himalayas.
- Orogeny: The Himalayan orogeny created a 100 km‑wide high‑land system with crustal shortening and thickening (~75 km).
- Isostasy: The high altitude of the Himalayas is supported by elevated lithospheric mantle (air‑filled asthenosphere).
- Erosion vs. Sedimentation: Fluvial systems transport ~50 km³ of sediment per year from the Himalayas to the Indo‑Gulf Basin.
Why it matters: The tectonic setting explains seismic hazard, mineral deposits, and the distribution of river basins.
2. Physical Geography
2.1 Continental Crust & Tectonics
| Feature | Geological Age | Key Processes | Implications |
|---|---|---|---|
| Himalayan Arc | ~50 Ma | Collisional thrust, metamorphism | Seismic hotspots, mineralization |
| Indo‑Gulf Basins | 40–30 Ma | Passive margin, sedimentation | Oil & gas potential |
| Deccan Traps | 66 Ma | Large igneous province | Basaltic soil, mining of iron ore |
2.2 Mountain Systems
- Himalayas: 3,000–8,600 m; 1,200 km length; 15 major peaks.
- Aravalli, Vindhya, Satpura, Eastern Ghats: Fold‑and‑thrust belts; 500–800 m elevation.
- Western Ghats: 1,600–2,600 m; 1,600 km; biosphere reserve under UNESCO.
Edge Case: Silent Himalayas
- Anomaly: The western side of the Himalayas (Sikkim, Arunachal Pradesh) experiences micro‑seismicity due to intraplate stresses.
2.3 Plateaus, Basins, and Plains
- Indian Plateaus: Deccan, Vindhya, and Deccan Plateaus; <700 m elevation.
- Alluvial Plains: Ganga, Brahmaputra, Indo‑Gulf; fertile but flood‑prone.
- Arid Basins: Thar Desert, Rann of Kutch; low rainfall (<250 mm).
Edge Case: High‑Altitude Desert – Ladakh
- Elevation >3,000 m, precipitation <200 mm; polar desert climate.
2.4 Coastal Morphology
- Coastal Types: Barrier beaches, estuarine plains, coastal dunes.
- Sediment Transport: Longshore drift shapes the east coast; wave refraction influences the west coast.
- Sea‑Level Rise: Coastal zones in Gulf of Kachchh and Bay of Bengal rising ~10 mm/yr.
Edge Case: Kanyakumari
- Only point where Indian Ocean, Arabian Sea, Bay of Bengal meet; geomorphologically a tri‑marine intersection.
2.5 Hydrography
| River | Length | Basin Area | Major Tributaries | Key Features |
|---|---|---|---|---|
| Ganga | 2,525 km | 1,000,000 km² | Yamuna, Ghaghara | Tributary network; Sunderbans delta |
| Brahmaputra | 2,900 km | 1,250,000 km² | Siang, Dibang | High sediment load |
| Godavari | 1,465 km | 350,000 km² | Seonath, Pranami | Largest peninsular river |
- Basin Modeling: Use hydrologic response units (HRUs) to predict flood peaks.
- Water Quality: Chloride and nitrate exceed WHO limits in 30% of rivers (citing 2023 Ministry of Water Resources).