Geography Optional – MAINS (Paper I)
Previous Year & High-Probability Questions
PAGE–1 : Geomorphology
Q1. Explain the concept of Plate Tectonics. How does it explain major landforms of the Earth?
Answer:
Plate Tectonics is a unifying theory that explains the movement of rigid lithospheric plates over the semi-molten asthenosphere.
These movements are driven by mantle convection, ridge push and slab pull forces.
At convergent boundaries, processes such as subduction and continental collision form fold mountains, trenches and volcanic arcs. Divergent boundaries lead to mid-oceanic ridges and rift valleys, while transform boundaries generate earthquakes.
Thus, plate tectonics explains the global distribution of earthquakes, volcanoes, mountains and ocean basins.
Q2. Distinguish between Endogenic and Exogenic processes. How do they interact to shape landforms?
Answer:
Endogenic processes originate within the Earth and include diastrophism, volcanism and earthquakes.
They are responsible for uplift, folding, faulting and crustal deformation.
Exogenic processes operate on the Earth’s surface through agents such as running water, wind, glaciers and waves. They lead to weathering, erosion, transportation and deposition.
Landforms are a result of continuous interaction between these two forces, where endogenic uplift provides relief and exogenic forces sculpt it.
Q3. Critically examine Davis’ Cycle of Erosion.
Answer:
Davis proposed that landscapes evolve through Youth, Maturity and Old age under conditions of tectonic stability.
Each stage is marked by characteristic landforms such as deep valleys, peneplains and reduced relief.
However, the model assumes uniform uplift, climate stability and ignores episodic tectonic activity. It fails to explain complex landscapes in tectonically active regions.
Despite limitations, Davis’ model laid the foundation for systematic geomorphological studies.
Q4. Compare Davis’ and Penck’s views on slope development.
Answer:
Davis viewed slope decline as a time-dependent process controlled by stages of erosion.
Penck, on the other hand, emphasized the role of crustal uplift rates in slope evolution.
Penck proposed waxing, waning and uniform slopes based on uplift intensity. His model is considered more dynamic and realistic in tectonically active regions.
Thus, Penck’s approach marked a shift from cyclic to process-based geomorphology.
Q5. Explain the role of weathering in landform development.
Answer:
Weathering is the in-situ breakdown of rocks through physical, chemical and biological processes.
It weakens rock structure and prepares material for erosion.
Chemical weathering dominates in humid climates, while mechanical weathering is prominent in arid and cold regions. Different weathering types influence soil formation and slope stability.
Hence, weathering is a critical link between rock structure and surface processes.
Q6. Discuss the formation of fluvial landforms in different stages of river development.
Answer:
In the youthful stage, rivers form V-shaped valleys, waterfalls and gorges due to vertical erosion.
The mature stage is marked by lateral erosion, meanders and floodplains.
In the old stage, deposition dominates, resulting in levees, oxbow lakes and deltas. These stages reflect changes in river energy and gradient.
Thus, fluvial landforms evolve systematically along the river course.
Q7. What are mass wasting processes? Explain their geomorphological significance.
Answer:
Mass wasting refers to downslope movement of weathered material under gravity.
It includes landslides, rockfalls, debris flows and soil creep.
These processes rapidly modify slopes and contribute significantly to sediment supply in fluvial systems. They are influenced by slope angle, rainfall, lithology and human activity.
Mass wasting plays a vital role in slope evolution and hazard formation.
Q8. Explain the concept of isostasy and its geomorphological implications.
Answer:
Isostasy refers to the state of gravitational equilibrium between the Earth’s crust and mantle.
According to Airy and Pratt models, crustal blocks float at different levels based on thickness or density.
Processes like glacial loading and unloading cause isostatic adjustment, leading to uplift or subsidence. This affects relief development and coastal changes.
Thus, isostasy explains long-term crustal stability and landscape evolution.
Q9. Discuss the significance of structural controls in landform development.
Answer:
Rock structure, lithology and joint patterns strongly influence landform shape.
Hard and resistant rocks form ridges, while softer rocks form valleys.
Structural features such as faults and folds guide river courses and slope orientation. Hence, geomorphology cannot be understood without geological structure.
Q10. How does geomorphology help in understanding natural hazards?
Answer:
Geomorphology provides insights into processes responsible for earthquakes, landslides, floods and coastal erosion.
Landform analysis helps identify hazard-prone zones.
Applied geomorphology is crucial for disaster mitigation, land-use planning and sustainable development. Thus, it bridges physical geography with human safety.
END OF PAGE–1 | Geography Optional – MAINS (Paper I)
A comprehensive UPSC & UPPSC resource covering
Objective (Prelims) • Analytical (Mains) • Interview Perspective
🔗 Open Full Geography PYQs Library
📚 Shaktimatha Learning Network
🗺️ Geography Optional – Complete Master Library
📘 UPSC & UPPSC – Complete Study Material
🎓 Learning Resource Hub | 📰 Daily Current Affairs | 💬 WhatsApp Channel
🌱 Shaktimatha Learning – Learn • Reflect • Grow
UPSC • UPPSC • Geography Optional • PYQs • Answer Writing
Concept clarity with exam-orientation
.png)
No comments:
Post a Comment