- 2076 Chaitra · 2 marks
Short note: Erosion
Short answer
Erosion is the wearing away of the earth's surface by agents (water, glacier, wind, waves) through abrasion, hydraulic action, solution and plucking. It causes scour at bridge piers, bank cutting, gully formation and reservoir siltation; in Nepal, steep Siwalik slopes erode rapidly.
Write a short note on erosion.
Erosion is the wearing away of the earth's surface by the removal of weathered material by agents such as running water, glacier, wind, sea waves and groundwater.
- Mechanisms: abrasion (scraping by carried load), attrition (particles wear each other), hydraulic action (force of water), corrosion/solution (chemical dissolving), deflation (wind lifting fine particles) and plucking (glacier pulling out blocks).
- Types: fluvial, glacial, aeolian, marine, and groundwater erosion.
- Factors: rock hardness, slope, rainfall, vegetation cover and human activity.
- Engineering effects: scour at bridge piers, bank cutting, gully formation, siltation of reservoirs, and loss of fertile soil. In Nepal the young, steep Siwalik and Mahabharat slopes erode very fast.
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