CBSE Class 11 India Physical Environment NCERT Solutions Chapter 7: Natural Hazards and Disasters

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NCERT Solutions PDF Class 11 PDF

This chapter delves into the critical topic of Natural Hazards and Disasters within the context of India's Physical Environment for Class 11 students. It explores various types of natural hazards, their causes, and the devastating impacts they can have on human life and property. The NCERT Solutions provide clear explanations and answers to key questions, helping students understand the geographical factors contributing to events like floods, landslides, and earthquakes, particularly in vulnerable regions of India. These solutions are designed to aid students in grasping the complexities of disaster management and preparedness, offering a solid foundation for their exam revision and a deeper understanding of India's diverse physical landscape.

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BoardCBSE
ClassClass 11
SubjectIndia Physical Environment
Session2026
LanguageEnglish
TypeNCERT Solutions
ChapterChapter 7

Chapter summary

Chapter 7 of the NCERT's India Physical Environment for Class 11 focuses on Natural Hazards and Disasters. The solutions cover multiple-choice questions identifying regions prone to floods and landslides, and specific river island locations. It also addresses the classification of hazards like blizzards and explains the conditions under which a hazard escalates into a disaster. Furthermore, it details the geological reasons behind the high incidence of earthquakes in the Himalayan and northeastern regions of India, emphasizing plate tectonics.

Learning outcomes

  • Identify regions in India frequently affected by floods.
  • Recognize the location of specific landslide-prone areas in India.
  • Understand the geographical factors contributing to river island formation.
  • Classify different types of natural hazards.
  • Differentiate between a hazard and a disaster.
  • Explain the geological causes of earthquakes in the Himalayan region.

Topics covered

Paper topics

  • Natural Hazards
  • Disasters
  • Floods
  • Landslides
  • Earthquakes
  • River Islands
  • Atmospheric Hazards
  • Plate Tectonics
  • Himalayan Geology
  • Disaster Mitigation
  • Hazard vs. Disaster
  • Regional Vulnerability

Important topics

  • Hazard vs. Disaster
  • Causes of Earthquakes in Himalayas
  • Flood-Prone Regions in India
  • Classification of Natural Hazards
  • Impact of Plate Tectonics

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Questions and Solutions

Question 1(i)

Which one of the following states of India experiences floods frequently?
  1. Bihar
  2. West Bengal
  3. Assam
  4. Uttar Pradesh.
Solution:

The correct option is (iii) Assam.

Assam is situated in the northeastern part of India and is traversed by the Brahmaputra River, which is known for its voluminous flow and prone to extensive flooding, especially during the monsoon season. The state's topography and heavy rainfall contribute to frequent inundation.

Question 1(ii)

In which one of the following districts of Uttaranchal did Malpa Landslide disaster take place?
  1. Bageshwar
  2. Champawat
  3. Almora
  4. Pithoragarh.
Solution:

The correct option is (iv) Pithoragarh.

The devastating Malpa landslide occurred in the Pithoragarh district of Uttarakhand (formerly Uttaranchal) in August 1998. This disaster resulted in significant loss of life and property.

Question 1(iii)

Which one of the following states receives floods in the winter months?
  1. Assam
  2. West Bengal
  3. Kerala
  4. Tamil Nadu.
Solution:

The correct option is (iv) Tamil Nadu.

While many parts of India experience monsoon floods during summer and autumn, Tamil Nadu can receive floods during the winter months. This is often due to the retreating monsoon or cyclonic disturbances that bring heavy rainfall to the state's coast during this period.

Question 1(iv)

In which of the following rivers is the Majuli River Island situated?
  1. Ganga
  2. Brahmaputra
  3. Godavari
  4. Indus.
Solution:

The correct option is (b) Brahmaputra.

Majuli is the largest river island in the world and is situated in the Brahmaputra River in the state of Assam, India. It is a unique geographical feature formed by the river's sediment deposition over centuries.

Question 1(v)

Under which type of natural hazards do blizzards come?
  1. Atmospheric
  2. Aquatic
  3. Terrestrial
  4. Biological.
Solution:

The correct option is (a) Atmospheric.

Blizzards are severe weather phenomena characterized by strong winds and heavy snowfall. As they are related to weather patterns and atmospheric conditions, they are classified under atmospheric hazards.

Question 2(i)

When can a hazard become a disaster?
Solution:

A hazard transforms into a disaster when its potential impact is realized, causing significant loss of life, property, and disruption to the community, especially when mitigating circumstances fail or are absent. For instance, a flood that leads to extensive damage and loss of life is a disaster. However, if early warnings and effective evacuation measures prevent such losses, the flood might be considered a hazard but not a disaster.

Question 2(ii)

Why are there more earthquakes in the Himalayas and in the north-eastern region of India?
Solution:

The increased frequency of earthquakes in the Himalayas and the northeastern region of India is primarily due to the ongoing collision between the Indian and Eurasian tectonic plates. The Indian plate is moving northward at a rate of approximately one centimeter per year. This movement is obstructed by the Eurasian plate, leading to a build-up of immense stress and energy along the plate boundaries. When this accumulated stress exceeds the rock's strength, it is released suddenly, resulting in earthquakes.

Common mistakes

  • Confusing hazards with disasters.
  • Incorrectly identifying flood-prone areas.
  • Not understanding the plate tectonic basis for Himalayan earthquakes.

Revision tips

  • Focus on the geographical locations mentioned for floods and landslides.
  • Clearly understand the definition and distinction between hazard and disaster.
  • Memorize the plate tectonic explanation for earthquakes in the Himalayas.
  • Review the classification of different types of natural hazards.

Practice MCQs

Q1. Which Indian state is known for experiencing floods very frequently?

Q2. The Malpa landslide disaster occurred in which district of Uttarakhand?

Q3. Which of these states experiences floods during the winter months?

Q4. The Majuli River Island, the largest river island in the world, is situated on which river?

Q5. Blizzards are classified under which category of natural hazards?

Q6. When does a hazard typically transform into a disaster?

Q7. The high frequency of earthquakes in the Himalayas is primarily due to:

Frequently asked questions

What is the main difference between a hazard and a disaster according to these solutions?

A hazard is a potential threat that can cause harm, while a disaster occurs when this hazard leads to significant loss of life, property, and societal disruption, often because mitigation efforts have failed or were inadequate.

Which regions in India are highlighted as being prone to frequent floods?

The solutions specifically mention Assam as a state that experiences floods frequently. Other regions might also be affected, but Assam is explicitly noted.

Why are the Himalayas a hotspot for earthquakes?

The Himalayas experience frequent earthquakes because the Indian tectonic plate is constantly moving northwards and colliding with the Eurasian plate, causing stress and energy build-up.

What type of natural hazard is a blizzard?

A blizzard is classified as an atmospheric hazard, characterized by heavy snowfall and strong winds.

Where is the Majuli River Island located?

The Majuli River Island is situated in the Brahmaputra River.

How can these NCERT solutions help in exam preparation?

These solutions provide clear, concise answers to chapter-specific questions, explain key concepts like hazard vs. disaster and earthquake causes, and highlight important geographical regions, aiding in focused revision for exams.

Important links

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