Physical Geography
Landforms, Atmosphere, Hydrosphere and Biosphere
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Overview
Physical Geography forms the foundation of geographical understanding in KTET Social Science. This topic examines Earth's natural systems—how landforms are created and shaped, how the atmosphere functions, the distribution and movement of water, and how living organisms interact with their environment. These concepts appear consistently in Category II and III examinations.
For KTET, you must understand both the processes that shape Earth's physical features and the interconnections between different spheres. Questions typically test your knowledge of landform types, atmospheric layers and phenomena, water cycle components, and ecological concepts. Kerala's unique physical setting—Western Ghats, backwaters, tropical monsoon climate—often provides context for application-based questions.
Mastering this topic requires understanding cause-effect relationships: why mountains form at convergent plate boundaries, why pressure belts create wind patterns, how the water cycle connects ocean and land. Think in terms of systems and cycles rather than isolated facts.
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Key Concepts
- **Lithosphere and Landforms**: Earth's crust consists of tectonic plates whose movements create mountains (fold, block, volcanic), plateaus (Deccan, Tibetan), and plains (alluvial, coastal). Weathering and erosion continuously reshape these landforms.
- **Endogenic vs Exogenic Forces**: Internal forces (earthquakes, volcanoes, mountain building) originate from Earth's interior; external forces (weathering, erosion by water, wind, ice) work on the surface. Both act simultaneously but at different timescales.
- **Atmospheric Structure**: The atmosphere has five layers—troposphere (weather occurs here, 0-12 km), stratosphere (ozone layer, 12-50 km), mesosphere, thermosphere, and exosphere. Temperature patterns differ in each layer.
- **Pressure Belts and Winds**: Unequal heating creates pressure belts—equatorial low, subtropical high, subpolar low, polar high. Air moves from high to low pressure, creating trade winds, westerlies, and polar easterlies.
- **Hydrological Cycle**: Water circulates continuously through evaporation, condensation, precipitation, and collection. About 97% of Earth's water is saline; only 3% is freshwater, mostly locked in ice caps and glaciers.
- **Biosphere as Life Zone**: The biosphere is the narrow zone where atmosphere, hydrosphere, and lithosphere interact to support life. Ecosystems are functional units within the biosphere containing biotic and abiotic components.