---
title: "Problems of Siwalik and Higher Himalaya"
subject: "Engineering Geology II"
chapter: 2
key: "semester_4/engineering_geology_ii:siwalik-higher-himalaya-problems"
source: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/siwalik-higher-himalaya-problems
site: BCT Engineering
---

# Problems of Siwalik and Higher Himalaya

Engineering Geology II · Chapter 2: Engineering Geology in Himalayas

- Asked in: 2081 Chaitra, 2 marks; 2075 Baisakh, 1+1 marks (asked 2 times)
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/siwalik-higher-himalaya-problems
- Whole chapter: https://www.bctengineer.com/md/semester_4/engineering_geology_ii/chapter-2

## Question

Describe the main engineering geological problems of the Siwalik and Higher Himalayan zones of Nepal.

## Short answer

Siwalik problems are landslides, erosion, and weak rocks. Higher Himalaya faces rock falls, snow avalanches, GLOFs, unstable moraines, tunnel rock burst and squeezing, earthquakes, and frost action, with difficult high-altitude construction.

## Answer

#### Siwalik zone
Composed of weakly cemented sandstone, mudstone and conglomerate.
- Landslides, gully erosion and debris flow due to weak rock and steep slope.
- Swelling and slaking of mudstone; poor aggregate.
- Active tectonics along MFT and MBT; earthquakes.
- Heavy sediment load and floods carried to the plains.

#### Higher Himalaya zone
Composed of high-grade metamorphic rocks: gneiss, schist, migmatite, quartzite and granite, with very high relief and glaciers.
- **Rock fall, rock avalanche and large rockslides** on steep, jointed slopes.
- **Snow avalanche, glacier hazards, GLOF and permafrost** thaw.
- **Unstable moraines and glacial deposits** that produce debris flows.
- **Tunnel problems:** high overburden gives rock burst and squeezing in shear zones; high in-situ stress.
- **Earthquakes** along the MCT and active faults.
- **Frost action** and very cold climate affect construction.
- **Access and construction** are difficult at high altitude.

## Check yourself

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

1. Which structures make the Siwalik tectonically active?
   A. MFT and MBT
   B. STDS only
   C. Indus-Tsangpo only
   D. None
   Answer: A. Active MFT and MBT give earthquakes in the Siwalik. (Key point: Siwalik tectonics)

2. Which hazard is typical of the Higher Himalaya but not the Siwalik?
   A. Gully erosion in mudstone
   B. Glacier hazards, GLOF and snow avalanches
   C. Waterlogging
   D. Arsenic
   Answer: B. High relief, glaciers and snow give GLOF, avalanches and permafrost problems. (Key point: Higher Himalaya hazard)

3. What happens in deep tunnels of the Higher Himalaya?
   A. Rock burst and squeezing from high overburden and stress
   B. Quicksand
   C. Karst sinkholes only
   D. No problems
   Answer: A. High overburden gives high in-situ stress, causing rock burst and squeezing in shear zones. (Key point: Deep tunnel)

## Related in Engineering Geology II

- [Engineering geological problems of Siwalik zone](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Asiwalik-problems) — Engineering Geology II, chapter 2, asked 4×
- [Problems of Higher and Tethys Himalaya](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Ahigher-tethys-problems) — Engineering Geology II, chapter 2
- [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
- [Problems of Lesser Himalaya and Terai](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Alesser-himalaya-terai-problems) — Engineering Geology II, chapter 2, asked 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×

## Related in other subjects

- [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
- [Discontinuities; Siwalik and Higher Himalaya lithology](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Adiscontinuities-siwalik-and-higher-himalaya) — Engineering Geology I, chapter 7
- [Lithology of Lesser and Tethys Himalaya; Siwalik difference](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Alithology-of-lesser-and-tethys) — Engineering Geology I, chapter 7
- [Physiographic division; Siwalik and Higher Himalaya](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aphysiographic-division-siwalik-and-higher) — Engineering Geology I, chapter 7