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Landslide Dams and Flash Floods

PYQs

7

Articles

1

Momentum

19

Phase IFoundation

Background

Overview

Directly relevant to GS1 (Physical Geography, Geomorphology, Natural Hazards), GS3 (Disaster Management, Environmental Impact Assessment), and understanding regional vulnerabilities in India, particularly in the Himalayan and Northeast regions.

Landslide dams are natural dams formed when a landslide blocks a river or stream, creating an impoundment or an artificial lake. These dams are inherently unstable and can breach suddenly, leading to catastrophic flash floods downstream, often referred to as Landslide Lake Outburst Floods (LLOFs).

Phase IIStatic core

Facts & tables

Key facts

Formation

Occur when large volumes of debris (rock, soil, vegetation) from a landslide fall into a river channel.

Instability

Prone to sudden failure due to overtopping, erosion, or seismic activity, leading to rapid release of impounded water.

Impact

Cause severe downstream flooding, destruction of infrastructure, loss of life, and significant environmental damage.

Vulnerability

Hilly and mountainous regions, especially those with heavy rainfall and seismic activity, are highly susceptible.

Reference table

Static syllabus anchors

TypeReference
Conceptual areaDisaster Management
Conceptual areaGeomorphology
Conceptual areaRiver Systems

Reference table

Institutions & roles

BodyRole
National Disaster Management Authority (NDMA)Formulates policies and guidelines for disaster management
State Disaster Management Authorities (SDMAs)Implements disaster management plans at state level
Border Roads Organisation (BRO)Restores connectivity and infrastructure in affected areas
Phase IIIExam lens

Prelims angle

Overview

Prelims angle: Multi-statement analysis

Prelims angle: Conceptual understanding

Quick revision

  • Landslide dams: river blockage by debris, forming artificial lakes.
  • High risk of sudden breach leading to catastrophic flash floods (LLOFs).
  • Common in geologically active, high-rainfall mountainous regions (e.g., Himalayas, NE India).
  • Significant threat to downstream lives, infrastructure, and environment.
  • Requires robust early warning systems and disaster preparedness.

High-confidence PYQs

2026Multi-statement analysis, Factual recall

Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India ? 1. Submergence of parts of the western coas...

GeographyOpen question

Consider the following statements about river bridges connecting India with neighbouring countries: 1. 'Maitri Setu', built over Feni river, connects Ramgar...

International RelationsOpen question
2026Multi-statement analysis, Conceptual understanding

Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India ? 1. Submergence of parts of the western coas...

GeographyOpen question

Consider the following statements about river bridges connecting India with neighbouring countries: 1. 'Maitri Setu', built over Feni river, connects Ramgar...

International RelationsOpen question
2025Multi-statement analysis, Factual recall

With reference to ancient India (600–322 BC), consider the following pairs: Territorial region – River flowing in the region I. Asmaka : Godavari II. Kamboj...

Ancient HistoryOpen question
2024Multi-statement analysis, Factual recall

Consider the following information: | Waterfall | Region | River | |--|--|--| |1. Dhuandhar | Malwa |Narmada| |2. Hundru | Chota Nagpur | Subarnarekha| |3....

GeographyOpen question
2022Factual recall, Conceptual understanding

Gandikota canyon of South India was created by which one of the following rivers?

GeographyOpen question
2019Multi-statement analysis, Factual recall

Consider the following pairs : | Glacier | River | |---------------|------------| | 1. Bandarpunch | Yamuna | | 2. Bara Shigri | Chenab ...

GeographyOpen question

Consider the following pairs: Famous place : River 1. Pandharpur : Chandrabhaga 2. Tiruchirappalli : Cauvery 3. Hampi : Malaprabha Which of the pairs given...

GeographyOpen question
2019Multi-statement analysis, Factual recall

Consider the following pairs : | Glacier | River | |---------------|------------| | 1. Bandarpunch | Yamuna | | 2. Bara Shigri | Chenab ...

GeographyOpen question

Consider the following pairs: Famous place : River 1. Pandharpur : Chandrabhaga 2. Tiruchirappalli : Cauvery 3. Hampi : Malaprabha Which of the pairs given...

GeographyOpen question

Topic timeline

Disaster ManagementGeomorphologyRiver Systems
Prelims 2019· Multi-statement analysis, Factual recall

Consider the following pairs : | Glacier | River | |---------------|------------| | 1. Bandarpunch | Yamuna | | 2. Bara Shigri | Chenab ...

Open question

Consider the following pairs: Famous place : River 1. Pandharpur : Chandrabhaga 2. Tiruchirappalli : Cauvery 3. Hampi : Malaprabha Which of the pairs given...

Open question
Prelims 2019· Multi-statement analysis, Factual recall

Consider the following pairs : | Glacier | River | |---------------|------------| | 1. Bandarpunch | Yamuna | | 2. Bara Shigri | Chenab ...

Open question

Consider the following pairs: Famous place : River 1. Pandharpur : Chandrabhaga 2. Tiruchirappalli : Cauvery 3. Hampi : Malaprabha Which of the pairs given...

Open question
Prelims 2022· Factual recall, Conceptual understanding

Gandikota canyon of South India was created by which one of the following rivers?

Open question
Prelims 2024· Multi-statement analysis, Factual recall

Consider the following information: | Waterfall | Region | River | |--|--|--| |1. Dhuandhar | Malwa |Narmada| |2. Hundru | Chota Nagpur | Subarnarekha| |3....

Open question
Prelims 2025· Multi-statement analysis, Factual recall

With reference to ancient India (600–322 BC), consider the following pairs: Territorial region – River flowing in the region I. Asmaka : Godavari II. Kamboj...

Open question
Prelims 2026· Multi-statement analysis, Factual recall

Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India ? 1. Submergence of parts of the western coas...

Open question

Consider the following statements about river bridges connecting India with neighbouring countries: 1. 'Maitri Setu', built over Feni river, connects Ramgar...

Open question
Prelims 2026· Multi-statement analysis, Conceptual understanding

Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India ? 1. Submergence of parts of the western coas...

Open question

Consider the following statements about river bridges connecting India with neighbouring countries: 1. 'Maitri Setu', built over Feni river, connects Ramgar...

Open question

Landslide dams river in rain-battered Arunachal, warning for Assam downstream

29 Jun 2026 · Landslide dams are temporary river blockages by debris, posing a significant flash flood risk upon breach, particularly in geologically unstable, high-rainfall regions like the Himalayas and Northeast India.

Read article

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