UPSC Civil Services – Geography
Topic: Physiography
Physiography (or geomorphology) is the branch of geography that deals with the study of the Earth's landforms, their classification, origin, evolution, and the processes that shape them.
1. Simple Explanation
- Physiography: The scientific description of the shape, texture, and distribution of the Earth’s surface.
- It links tectonics (rock uplift), climate, biological activity, and human influence to produce the mosaic of landforms we see.
- For UPSC: Helps in answering questions on regional development, natural hazards, resource distribution, and environmental planning.
2. Key Points
| Section | What to Know |
|---|---|
| A. Core Concepts | - Landform = any distinctive physical feature of the earth’s surface. - Geomorphic processes: Uplift, weathering, erosion, deposition, mass wasting, volcanic activity. |
| B. Physiographic Units | 1. Mountain Ranges (e.g., Himalayas, Western Ghats) 2. Hills (e.g., Shivalik, Aravalli) 3. Plateaus (e.g., Deccan Plateau, Chota Nagpur Plateau) 4. Plains (e.g., Indo‑Gangetic Plain, Bay of Bengal Plain) 5. Coastal Plains (e.g., Bengal, Tamil Nadu) 6. Islands (e.g., Andaman & Nicobar, Lakshadweep) 7. Deserts (e.g., Thar) |
| C. Major Physiographic Divisions of India | 1. Himalayan Region – Highest peaks, active tectonics. 2. Indo‑Gangetic Plain – Alluvial, fertile, high population density. 3. Peninsular Shield – Precambrian crystalline rocks, high plateaus. 4. Coastal Plains – Sedimentary deposits, fertile deltas. 5. Island Chains – Volcanic, coral, and sedimentary islands. |
| D. Characteristic Features | • Himalayas – High relief, active seismicity, glaciation. • Indo‑Gangetic Plain – Low relief, alluvial fans, fertile soil. • Deccan Plateau – Basaltic lava flows, rugged, rich minerals. • Coastal Plains – Deltaic deposits, cyclones, tidal flats. |
| E. Processes Shaping Physiography | - Tectonic uplift (e.g., collision of Indian & Eurasian plates). - Erosion & Weathering (chemical, physical). - Sedimentation (alluvium, deltas). - Volcanism (lava flows, basalt columns). - Mass Wasting (landslides, debris flows). |
| F. Relevance to UPSC | - Natural resource distribution (coal, minerals, water). - Disaster management (earthquakes, floods, landslides).<nobr>- Planning of infrastructure (highways, rail corridors). - Environmental conservation (growing forests, wildlife corridors). |
3. Worked Example
Question (Sample UPSC):
“Classify the physiography of the state of Tamil Nadu and discuss major geomorphic processes shaping it.”
Step‑by‑Step Solution
-
Locate the State – Southern India, part of the Indian Peninsula.
-
Identify Major Physiographic Units
- Coastal Plains (east coast): Bay of Bengal Coastal Plain, narrow, alluvial, suitable for agriculture.
- Western Ghats (western border): Mountain range, high relief, evergreen forests.
- Deccan Plateau (central part): Basaltic plateau, rugged, shallow valleys.
- Kaveri Delta (southern part): Alluvial delta, fertile, highly populated.
-
List Key Features
- Coastal Plains – Sedimentary deposits, low elevation, subject to cyclones.
- Western Ghats – Highest peak (Kodaikanal), high rainfall, endemic flora.
- Deccan Plateau – Basaltic rock, basalt columns, rich in iron ore.
- Kaveri Delta – Alluvial fan, rice cultivation.
-
Geomorphic Processes
- River Erosion & Deposition – Kaveri & its tributaries carve valleys and deposit alluvium.
- Weathering & Mass Wasting – In Western Ghats, intense rainfall causes landslides.
- **Tectonic U