CAPF AC 2022 Q119: Geography – Physical Geography & Geomorphology
- (a) desert regions
- (b) karst regions
- (c) permafrost regions
- (d) savanna regions
Answer: (c) permafrost regions
Explanation
Solifluction
How to think: break the word: soli (soil) + fluction (flow).
It is the slow downhill flow of water-soaked soil.
It happens where the ground below stays frozen, so melt water cannot drain away.
| Step | What happens |
|---|---|
| Winter | The whole ground is frozen |
| Summer | Only the top layer thaws |
| Trapped water | The frozen layer below (permafrost) stops water from sinking |
| Flow | The soggy top layer creeps slowly down even gentle slopes |
Where: tundra and high mountain (periglacial) regions with permafrost.
Other mass movements: creep, earthflow, mudflow, landslide and rockfall.
Answer: (c) permafrost regions.
Why each option is right or wrong
- (a) Incorrect. Deserts lack the water needed for soil to flow.
- (b) Incorrect. Karst regions are known for solution features such as sinkholes.
- (c) CORRECT. Solifluction is typical of permafrost (periglacial) regions.
- (d) Incorrect. Savanna regions have no frozen subsoil.
Key point
Solifluction: slow flow of saturated soil over frozen ground; periglacial and tundra regions. Mass movements (NCERT): slow (creep, solifluction) and rapid (earthflow, mudflow, debris avalanche, landslide).
Remember
Solifluction = soil flow over permafrost.
Common mistakes
- Linking soli with the Sun and choosing deserts or savanna.
- Mixing up solifluction with solution in karst regions.
- Thinking it is a fast movement like a landslide; it is very slow.
Exam tip
Educated guess: soil can flow only when it is soaked and cannot drain. A frozen layer underneath is the one thing that keeps water trapped on a slope.
Sources
- NCERT Class XI Geography — Fundamentals of Physical Geography, Chapter 6: Geomorphic Processes (mass movements)
- Arthur N. Strahler and Alan H. Strahler, Physical Geography — Mass Wasting