NIOS Class 12 Geography Chapter 18 Natural Disasters

NIOS Class 12 Geography Chapter 18 Natural Disasters, Solutions to each chapter is provided in the list so that you can easily browse throughout different chapters NIOS Class 12 Geography Chapter 18 Natural Disasters and select need one. NIOS Class 12 Geography Chapter 18 Natural Disasters Question Answers Download PDF. NIOS Study Material of Class 12 Geography Notes Paper 316.

NIOS Class 12 Geography Chapter 18 Natural Disasters

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Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 12 Geography Chapter 18 Natural Disasters, NIOS Senior Secondary Course Geography Solutions for All Chapter, You can practice these here.

Natural Disasters

Chapter: 18




Q.1. When do natural events become natural hazards?

Ans. When physical events pose danger to humans and their property they are called hazards.

Q.2. What is tsunami?

Ans. Tsunami is large sea waves caused by earthquake below sea water. It causes heavy destruction to life and property on coastal areas thousand of kilometre away from its origin.


Q.1. Name any two causes of flood.

Ans. (i) Heavy rains.

(ii) deforestation.

(iii) cyclones.

(iv) tsunami. 

Q.2. How much area of the country is flood prone?

Ans. 4 crore hectares.

Q.3. Name any two measures of flood control.

Ans. (i) Construction of reservoirs and 

(ii) embankments or three plantation.


Q.1. What is a drought?

Ans. The rainfall deficiency during a long period, over a large area is called a drought.

Q.2. Fill in the blanks with appropriate words out of those given in the brackets:

(i) The most drought prone state of India is ______. (Assam, Rajasthan, Chhattisgarh.)

Ans. Rajasthan.

(ii) In drought prone areas the impact of drought can be minimised by adopting ________.(Flood irrigation, Sprinkler irrigation)

Ans. Sprinkler irrigation.


Q.1. Name any two causes of landslides.

Ans. Earthquakes, volcanic explosions, heavy rain, deforestation, road construction, shifting agriculture  

Q.2. Name two most landslide prone areas.

Ans. (i) Himalayas and 

(ii) Western Ghats.

Q.3. Choose the correct answer given in the brackets:

(i) Which state of South India is landslide prone? (Andhra pradesh, Tamil Nadu)

Ans. Tamil Nadu.

(ii) Which measure is adopted to control landslide? (Levelling of slopes, constructing of strong wall of the slope)

Ans. Constructing of strong wall on the slope.


Q.1. In which state did the earthquake occur on the occasion of republic day of 2001?

Ans. Gujarat.

Q.2. What name is given to the high sea wave triggered by earthquake?

Ans. Tsunami.

Q.3. In which earthquake zone Delhi has been included on the basis of the intensity of the earthquakes?

Ans. Zone No. IV.


Q.1. Which are the most cyclone prone months?

Ans. October, November, December, April and may.

Q.2. Which state was hit the seriously devastating cyclone on 29th October, 1999?

Ans. Orissa.

Q.3. Which state is most vulnerable to cyclone on the western coast of India?

Ans. Gujarat.


Q.1. Differentiate between natural hazard and natural disaster.


Natural HazardNatural Disaster
1. A Hazard is a dangerous physical condition or event.1. A disaster disrupts the normal function of the society caused by a hazard.
2. Earthquakes, floods, volcanic, eruption landslides, drought etc. are called natural hazards before they cause loss of life and damage to property.2. It causes damage to property and loss of life but it disrupts the opportunity of employment also.
3. Small number of people are affected.3. A large number of people are affected by it.
4. It may cause injury, loss of life or damage of property.4. It causes wide spread loss of life and property.
5. Earthquakes, floods, volcanoes, tsunami, landslide, drought etc.are natural hazards.5. It effects the society to such an extent that external aid becomes necessary to compensate the losses.

Q.2. What is a flood? Explain the causes of flood and its destruction.

Ans. The inundation of an area by water is called a flood.

Causes of flood: The causes of flood are as under:

1. Heavy rainfall: Heavy rain in the catchment area of a river causes water to overflow its banks which results in flooding of nearby areas.

2. Sediment deposition: River neds become swallow due to sedimentation. As a result the heavy rain water overflow the river banks.

3. Deforestation: Vegetation hampers the flow of water and forces it to percolate in the ground. As a result of deforestation, the land becomes obstruction free and water flows with greater speed into the rivers and causes flood.

4. Cyclone: Cyclone generated sea waves of abnormal height spreads the water in the adjoining coastal areas.

5. Interference in drainage system: The drainage congestion caused by badly construction of bridges, roads etc. hamper the flow of water and the result is flood.

6. Change in course of river: Meanders and change in course of the river cause floods.

7. Tsunami: Large coastal areas are flooded by rising sea water when a Tsunami strikes the coast.

8. Destruction: Humans an animals are both affected buy flood. Houses are damaged. Crops are submerged in flood water, wild animals die. Outbreak of epidemics like malaria and diarrhoea are common after flood.

Q.3. Describe the drought prone areas of India.

Ans. Drought prone areas of India: These are south-west Rajasthan, Tamil Nadu, Madya Pradesh, Central Maharashtra, Andhra Pradesh and Karnataka.

Q.4. What is a landslide? What activities of human beings have increased the frequency of landslides?

Ans. The sleeping of masses of rocks, earth ot debris downwards on the mountain slops or banks on the rivers is called a landslide.

The activities of human beings have increased the frequency of landslides. The human activities such as construction of houses and other buildings is the cause of increasing frequency of landslides. In construction processes large amount of debris are created. This causes the landslides.

Q.5. What is an earthquake? Describe its impact of humans.

Ans. The sudden shaking or trembling of the earth’s surface is an earthquake.

Impact of earthquake on humans: Duration of tremors of earthquake is normally of only few seconds but thousands of people may die in short period. Five severely devastating earthquakes have occured in India between 1988 and 26 January 2001. Nearly 31000 people lost their lives. Numerous people lost their shelter and many became orphans. The destruction of property was tremendous and could not be estimated properly.

Q.6. When do cyclones occur in India? Describe the measures adopted for protection from the cyclones.

Ans. Cyclone is concentrated to certain seasonal cyclic segment. In India, most of the cyclones occur in the post monsoon season i.e. from October to December or in pre monsoon season from April to May. The life span of a cyclone is 7 to 14 days.

Measures for protection from the cyclone: developed countries have evolved measures Tum mitiga fury of cyclone. The warning of cyclone is issued. They are broadcasting and telecasted at right time. This saves life of people.

Sham do’s and don’t as measures of cyclone protection are as under:

1. Listen to the ratio for advance information and advice.

2. Keep considerable margin of time for safety.

3. A cyclone may change direction, speed, or intensity within a few hours, so stay tuned to the radio for updated information.

4. Stay in the house and take shelter in the stronger portion of your house.

5. Listen to the radio and follow instructions.

6. Open windows of the safe portion of the house if the roof begins to lift.

7. Find shelter if you are in open at the hitting time of the cyclone.

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