---
title: "Himalayan hazards and mitigation"
subject: "Engineering Geology II"
chapter: 5
key: "semester_4/engineering_geology_ii:himalaya-hazards-mitigation"
source: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/himalaya-hazards-mitigation
site: BCT Engineering
---

# Himalayan hazards and mitigation

Engineering Geology II · Chapter 5: Geological Hazards

- Asked in: 2079 Jestha, 4+2 marks
- Video: [GLOF Risk Management in Sikkim ](https://www.youtube.com/watch?v=ZM4M_oyYBTQ) — Embassy of Switzerland in India
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/himalaya-hazards-mitigation
- Whole chapter: https://www.bctengineer.com/md/semester_4/engineering_geology_ii/chapter-5

## Question

Describe the major geological hazards of the Himalayas and their mitigation measures.

## Short answer

Major Himalayan hazards are earthquakes, landslides and debris flows, floods, GLOF, avalanches, soil erosion, and subsidence. Mitigation involves hazard mapping and zoning, landslide and flood control structures, GLOF monitoring and lake lowering, earthquake-resistant design, afforestation, and community preparedness.

## Answer

#### Major geological hazards of the Himalaya
1. **Earthquakes** from active thrusts (MFT, MBT, MCT), e.g. the 2015 Gorkha earthquake.
2. **Landslides, rock falls and debris flows** on steep slopes of weak rock during the monsoon.
3. **Floods and flash floods;** river bank erosion and sedimentation (Terai).
4. **GLOF and LDOF** in the high mountains.
5. **Snow avalanches** and glacier hazards.
6. **Soil erosion and gullying** in the Siwaliks.
7. **Subsidence and karst** in limestone areas.

#### Mitigation measures
1. Hazard mapping, zoning and land-use control; avoiding dangerous locations.
2. Landslide control: drainage, slope grading, retaining walls, rock bolts, bio-engineering, and check dams for debris flows.
3. Flood control: embankments, spurs, river training, early warning.
4. GLOF: monitoring, lake-level lowering, early warning systems.
5. Earthquake-resistant design following NBC, retrofitting, avoiding active faults.
6. Afforestation, watershed management and controlled road construction.
7. Community awareness, disaster preparedness and monitoring.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which structures produce Himalayan earthquakes?
   A. Glacial moraines
   B. Sea waves
   C. Active thrusts MFT, MBT and MCT
   D. Volcanoes
   Answer: C. Active thrusts such as MFT, MBT, MCT cause earthquakes. (Key point: Earthquake source)

2. Which is a flood control measure?
   A. Rock bolts
   B. Lake-level lowering
   C. Retrofitting of buildings
   D. Embankments, spurs and river training
   Answer: D. Flood control uses embankments, spurs, training and early warning. (Key point: Flood control)

3. What helps control debris flow?
   A. Check dams
   B. Spurs for earthquakes
   C. Retrofitting
   D. Grouting cavities
   Answer: A. Check dams slow debris flow. (Key point: Debris flow control)

## Related in Engineering Geology II

- [Mitigation of geological hazards](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Ageohazard-mitigation-measures) — Engineering Geology II, chapter 5
- [Geological hazards of Higher Himalaya](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Ahigher-himalaya-hazards) — Engineering Geology II, chapter 2
- [Mitigation of geological problems in Himalaya](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Ahimalaya-problems-mitigation) — Engineering Geology II, chapter 2
- [Mitigation measures of erosion](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Aerosion-mitigation) — Engineering Geology II, chapter 5
- [Problems of Lesser Himalaya with mitigation](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Alesser-himalaya-problems) — Engineering Geology II, chapter 2, asked 5×