Q. “The Himalayas are highly prone to landslides.” Discuss the causes and suggest suitable measures of mitigation. [250 Words, 15 Marks]
Why the Question?
UPSC PYQ – CSE Mains – 2016
Keywords of the Question
- Himalayas – highly prone to landslides
- Causes
- Measures of mitigation
Directive Word
Discuss – Essentially this is a written debate where you are using your skill at reasoning, backed up by carefully selected evidence to make a case for and against an argument, or point out the advantages and disadvantages of a given context. Remember to arrive at a conclusion
How to approach this Question?
Introduction
- Define landslides.
- Mention the high susceptibility of the Himalayas to landslides.
- Briefly state the significance of understanding causes and mitigation measures.
Body
- Causes of Landslides in the Himalayas:
- Geological factors (e.g., tectonic activity, young fold mountains).
- Climatic factors (e.g., heavy monsoon rains, snowmelt).
- Anthropogenic factors (e.g., deforestation, construction activities).
- Mitigation Measures:
- Structural measures (e.g., retaining walls, slope stabilization).
- Non-structural measures (e.g., early warning systems, land-use planning).
- Community-based approaches (e.g., awareness programs, local participation).
Conclusion
- Summarize the importance of addressing landslides in the Himalayas.
- Highlight the need for a multi-faceted approach combining scientific, structural, and community-based measures.
- End with a forward-looking statement on sustainable development and disaster resilience.
Note: Please note that the following ‘answers’ are not ‘model answers’ nor are they synopses in the strictest sense. Instead, they are content designed to meet the demands of the question while providing comprehensive coverage of the topic.
Answer Key
Introduction
Landslides are a common natural disaster in mountainous regions, characterized by the downward movement of rock, soil, and debris. The Himalayas, being young fold mountains, are particularly susceptible to landslides due to their geological and climatic conditions. Understanding the causes and implementing effective mitigation measures is crucial for reducing the impact of landslides in this region.
Body
Causes of Landslides in the Himalayas:
- Geological Factors:
- Tectonic Activity: The Himalayas are seismically active due to the collision of the Indian and Eurasian plates, leading to frequent earthquakes that destabilize slopes.
- Example: The 2015 Nepal earthquake triggered numerous landslides across the region1.
- Young Fold Mountains: The Himalayas are geologically young and structurally unstable, making them prone to landslides.
- Tectonic Activity: The Himalayas are seismically active due to the collision of the Indian and Eurasian plates, leading to frequent earthquakes that destabilize slopes.
- Climatic Factors:
- Heavy Monsoon Rains: Intense rainfall during the monsoon season saturates the soil, reducing its cohesion and triggering landslides.
- Example: The 2013 Uttarakhand floods caused massive landslides, leading to significant loss of life and property2.
- Snowmelt: Rapid melting of snow in spring increases water infiltration into the soil, leading to slope failure.
- Heavy Monsoon Rains: Intense rainfall during the monsoon season saturates the soil, reducing its cohesion and triggering landslides.
- Anthropogenic Factors:
- Deforestation: Removal of vegetation for agriculture and development reduces root strength, which helps in binding the soil, thus increasing landslide risk.
- Example: Deforestation in the Western Ghats has led to increased landslide occurrences3.
- Construction Activities: Unplanned construction of roads, buildings, and dams disturbs the natural slope stability.
- Deforestation: Removal of vegetation for agriculture and development reduces root strength, which helps in binding the soil, thus increasing landslide risk.
- Soil and Rock Characteristics:
- Loose Soil and Weathered Rock: The presence of loose, unconsolidated soil and weathered rock layers can easily give way under stress.
- Example: The 2014 Malin landslide in Maharashtra was partly due to loose soil conditions4.
- Loose Soil and Weathered Rock: The presence of loose, unconsolidated soil and weathered rock layers can easily give way under stress.
- Hydrological Factors:
- Water Infiltration: Excessive water infiltration due to poor drainage systems can increase pore water pressure, leading to slope failure.
Mitigation Measures:
- Structural Measures:
- Retaining Walls: Construction of retaining walls to support unstable slopes and prevent soil movement.
- Example: Retaining walls have been used effectively in Japan to mitigate landslide risks.
- Slope Stabilization: Techniques like terracing, rock bolting, and geotextiles to stabilize slopes.
- Retaining Walls: Construction of retaining walls to support unstable slopes and prevent soil movement.
- Non-Structural Measures:
- Early Warning Systems: Implementation of landslide early warning systems using sensors and monitoring equipment.
- Example: Early warning systems in Taiwan have helped reduce landslide-related casualties.
- Land-Use Planning: Regulating land use in vulnerable areas to prevent construction and deforestation.
- Early Warning Systems: Implementation of landslide early warning systems using sensors and monitoring equipment.
- Community-Based Approaches:
- Awareness Programs: Educating local communities about landslide risks and safety measures.
- Example: Community awareness programs in Nepal have improved local preparedness for landslides.
- Local Participation: Involving local communities in planning and implementing mitigation measures.
- Awareness Programs: Educating local communities about landslide risks and safety measures.
- Afforestation:
- Planting Trees: Promoting afforestation and reforestation to enhance slope stability through root reinforcement.
- Example: Afforestation projects in the Western Ghats aim to reduce landslide risks.
- Planting Trees: Promoting afforestation and reforestation to enhance slope stability through root reinforcement.
- Engineering Solutions:
- Drainage Improvement: Installing proper drainage systems to reduce water infiltration and pore water pressure.
- Example: Improved drainage systems in Hong Kong have significantly reduced landslide occurrences.
- Drainage Improvement: Installing proper drainage systems to reduce water infiltration and pore water pressure.
Conclusion
Addressing landslides in the Himalayas requires a comprehensive approach that combines scientific, structural, and community-based measures. By understanding the causes and implementing effective mitigation strategies, we can reduce the risk and impact of landslides, ensuring sustainable development and disaster resilience in the region.
Mind Map
