Natural Hazards and Disasters 


EXERCISES

1. Choose the right answer from the four alternatives given below.

(i) Which one of the following states of India experiences floods frequently?

(a) Bihar (c) Assam

(b) West Bengal (d) Uttar Pradesh

Ans: (c) Assam.

(ii) In which one of the following districts of Uttaranchal did Malpa Landslide

disaster take place?

(a) Bageshwar (c) Almora

(b) Champawat (d) Pithoragarh

Ans: (d) Pithoragarh.

(iii) Which one of the following states receives floods in the winter months?

(a) Assam (c) Kerala

(b) West Bengal (d) Tamil Nadu

Ans:  (d) Tamil Nadu.

(iv) In which of the following rivers is the Majuli River Island situated?

(a) Ganga (c) Godavari

(b) Brahmaputra (d) Indus

Ans: (b) Brahmaputra.

(v) Under which type of natural hazards do blizzards come?

(a) Atmospheric (c) Terrestrial

(b) Aquatic (d) Biological

Ans: (a) Atmospheric.

2. Answer the following questions in less than 30 words.

(i) When can a hazard become a disaster?

Ans: A hazard transforms into a disaster when its impact overwhelms the ability of a community to cope, causing significant damage, loss of life, and disruption. It's not just the event's intensity, but also vulnerability and lack of preparedness that turn risk into disaster.

(ii) Why are there more earthquakes in the Himalayas and in the north-eastern region of India?

Ans: Two main reasons:

1. Plate collision: The Indian Plate is pushing northward, colliding with the Eurasian Plate. This constant friction and pressure release trigger earthquakes along the Himalayan arc and neighboring regions.

2. Active fault lines: These regions are riddled with active fault lines, like the Main Boundary Thrust, where frequent movements and energy build-up lead to earthquakes.

(iii) What are the basic requirements for the formation of a cyclone?

Ans: Cyclones need three key ingredients:

1. Warm ocean waters: At least 26°C to fuel evaporation and provide energy for the storm.

2. Low pressure area: A disturbance in the atmosphere where air rises, creating a spinning vortex.

3. Coriolis force: Earth's rotation influences wind direction, causing the vortex to spiral and intensify.

Think of it as a warm, low-pressure dance with a twist, leading to the whirling birth of a cyclone.

(vi) How are the floods in Eastern India different from the ones in Western India?

Ans: Eastern India: Frequent monsoon floods, heavy rainfall, widespread, major rivers overflow, impacts agriculture & infrastructure. Western India: Less frequent, cyclone or monsoon flash floods, intense & localized, smaller rivers, damages coastal areas & specific regions.

(v) Why are there more droughts in Central and Western India?

Ans:  Two key reasons:

1. Less and erratic rainfall: Lower average rainfall compared to other regions, plus unreliable monsoon patterns lead to water scarcity.

2. High temperatures and evaporation: Hot climate with intense sunshine dries up the land quickly, exacerbating the water deficit.

Think: Less rain, more heat, equals frequent droughts.

3. Answer the following questions in not more than 125 wordjs.

(i) Identify the Landslide-prone regions of India and suggest some measures to

mitigate the disasters caused by these.

(ii) What is vulnerability? Divide India into natural disaster vulnerability zones

based on droughts and suggest some mitigation measures.

(iii) When can developmental activities become the cause of disasters?

Project/Activity

Prepare a project report on any one of the topics given below.

(i) Malpa Landslide (v) Tehri Dam/Sardar Sarovar

(ii) Tsunami (vi) Bhuj/Latur Earthquakes

(iii) Odisha and Gujarat Cyclones (vii) Life in a delta/riverine island

(iv) Inter-linking of rivers (viii) Prepare a model of rooftop rainwater

harvesting



Answer By: Himashree Bora.