---
title: "Why Nepal Himalaya is landslide-prone"
subject: "Engineering Geology II"
chapter: 5
key: "semester_4/engineering_geology_ii:nepal-landslide-prone"
source: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/nepal-landslide-prone
site: BCT Engineering
---

# Why Nepal Himalaya is landslide-prone

Engineering Geology II · Chapter 5: Geological Hazards

- Asked in: 2071 Bhadra, 4 marks
- Video: [Landslides & It's Prevention | Dr. Tara Nidhi Bhattarai | Sushant Pradhan Podcast](https://www.youtube.com/watch?v=CKrhi_pbdI8) — Sushant Pradhan
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/nepal-landslide-prone
- Whole chapter: https://www.bctengineer.com/md/semester_4/engineering_geology_ii/chapter-5

## Question

Explain why the Nepal Himalaya is very prone to landslides.

## Short answer

Nepal Himalaya is highly prone to landslides due to active tectonics and steep slopes, weak fractured rocks (phyllite, schist, shale), adverse dipping structures, intense monsoon rainfall, deep weathering, thick colluvium, earthquake shaking, and human activities like unplanned road cutting and deforestation.

## Answer

The Nepal Himalaya is very prone to landslides due to a combination of geological, topographic, climatic and human factors.

1. **Young, active tectonics:** the Himalaya is still rising due to the Indo-Eurasian collision (about 4-5 cm/year), producing steep, unstable slopes and frequent earthquakes that trigger slides.
2. **Steep topography:** very high relief and steep slopes; rivers cut deep gorges and undercut the toe.
3. **Weak and fractured rocks:** phyllite, schist, slate, shale and Siwalik mudstone; the rocks are folded, faulted and highly jointed, especially near the MBT and MCT.
4. **Adverse structure:** foliation and joints dipping out of the slope.
5. **Intense monsoon rainfall:** about 80% of the annual rainfall falls in June-September, with cloudbursts, increasing pore water pressure and erosion.
6. **Weathering:** deep weathering and thick colluvium and residual soil.
7. **Glaciers and snow melt** in high areas.
8. **Human activity:** unplanned road construction by bulldozer, deforestation, agriculture on steep slopes, quarrying and settlements.
9. **Earthquakes:** the 2015 earthquake triggered thousands of landslides.

## Check yourself

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

1. Why is the Himalaya prone to landslides tectonically?
   A. Subsiding
   B. Flat
   C. Still rising due to collision, giving steep unstable slopes and earthquakes
   D. Tectonically dead
   Answer: C. Collision at 4-5 cm/yr. (Key point: Tectonics)

2. What role does monsoon play?
   A. Dry
   B. Reduces erosion
   C. Freezes
   D. 80% of rain in June-September increases pore pressure
   Answer: D. Cloudbursts. (Key point: Monsoon)

3. Which rocks are weak?
   A. Phyllite, schist, slate, shale, Siwalik mudstone
   B. Granite
   C. Quartzite
   D. Basalt
   Answer: A. Weak and fractured. (Key point: Weak rocks)

4. Which human activity is highlighted?
   A. Check dams
   B. Unplanned bulldozer road construction
   C. Reforestation
   D. Terracing
   Answer: B. Along with deforestation. (Key point: Human activity)

## Related in Engineering Geology II

- [Major discontinuity systems of Nepal Himalaya](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Anepal-discontinuity-systems) — Engineering Geology II, chapter 2, asked 12×
- [Factors causing hazards in Nepal Himalaya](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Anepal-himalaya-hazard-factors) — Engineering Geology II, chapter 5
- [Landslide causes and mitigation](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Alandslide-causes-mitigation) — Engineering Geology II, chapter 5, asked 6×
- [Problems of Siwalik and Higher Himalaya](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Asiwalik-higher-himalaya-problems) — Engineering Geology II, chapter 2, asked 2×

## Related in other subjects

- [Physiographic division of the Nepal Himalaya](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aphysiographic-division-of-the-nepal) — Engineering Geology I, chapter 7, asked 7×
- [Tectonic divisions of the Nepal Himalaya](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Atectonic-divisions-of-the-nepal) — Engineering Geology I, chapter 7, asked 4×
- [Discontinuities and engineering problems in Nepal Himalaya](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Adiscontinuities-and-engineering-problems-in) — Engineering Geology I, chapter 7
- [All mass movements are landslides](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aall-mass-movements-are-landslides) — Engineering Geology I, chapter 6