10th Standard, Karnataka Social/ Geography CHAPTER – 29
INDIA – NATURAL DISASTERS
EXERCISES
I. Answer the following questions in brief:
- What are natural disasters?
Answer: Many incidents occurring in Nature are beyond human control. Preventing these and predicting their occurrence at a certain place is beyond science too. Naturally-occurring destructive incidents resulting in loss of human life and property are called natural disasters.
- What are the effects of cyclones?
Answer: The effects of cyclones are as follows.
a. Cyclones are very destructive. Sometimes, the life of the people of cyclone-hit areas gets totally changed.
b. They cause large scale deaths.
c. Ocean tides inundate the inland water-bodies and make them salty.
d. Crops get totally destroyed.
e. Transport links, electricity supply and the daily life of the of people get affected badly.
f. Cyclone-hit areas suffer from infectious diseases, leading to huge casualties. - What are floods?
Answer: When there is heavy rainfall and excessive melting of ice, the volume of water increases in the river leading it to overflow. This is called “floods”.
- What is Landslide?
Answer: Land mass sliding down the slopes from mountains or hills are called land slide. - What is Earthquake?
Answer: Vibration or movement of the upper layers of the earth due to the pressure created inside is called Earthquake. - What are the causes of floods? Describe flood-prone areas in India.
Answer: The causes of floods are,
a. The uncertainty of monsoon rainfall sometimes gets heavy rainfall causes floods.
b. Accumulation of silt in the rivers leads to overflowing of water on either side of the river, causing floods.
c. Breach of dams or retention walls leads to sudden release of large quantity of water resulting in floods.
d. Rivers changing their course can also cause floods.
e. Heavy rainfall during cyclones can also lead to floods.
f. Earthquakes in the sea are also causes floods.
Apart from the natural causes mentioned above, man-made causes like deforestation, improperly built dams, weak retention walls, and illegal encroachment of land are also important causes.
Flood-prone regions are found all over the country.
a. The Ganges and its tributaries Yamuna, Gandak, Kosi and Ghagra rivers cause floods in Uttar Pradesh and Bihar.
b. Damodar and Suvarnarekha rivers cause floods in Chattisgarh and West Bengal states.
c. Brahmaputra and its tributaries Dibang, Dihang, Subansiri and Lohit rivers cause floods in Assam.
d. Cloudburst often causes abrupt floods in the Himalayas.
e. Narmada, Tapti, Sabaramathi and Mahi rivers cause floods for some days in a year in the state of Gujarat.
f. Krishna, Tungabhadra, Ghataprabha, Malaprabha, Dhoni, Bennehalla etc. cause floods during rainy season in Karnataka.
- What is Coastal Erosion? Mention its management.
Answer: The erosion of land by the waves in the coastal areas is called coastal erosion. Prevention or management of Coastal erosion can be done as follows.
a. Prohibiting sand mining in coastal areas.
b. Constructing retention walls along the length of coast wherever waves are strong.
c. Stocking of large rocky boulders along the coast to reduce the impact.
d. The most effective method of preventing coastal erosion is by growing mangrove forests along the coast.
- Write about the effects of earthquake and precautions to be taken.
Answer: The effects of earthquake are,
1 . The loss of life and destruction of property, 2. Obstruction to transport, 3. Spread of infectious diseases, 4. Increased tidal activity, 5. Tsunamis, 6. Change in river’s direction.
The precautions to be taken to earthquake are,
a. Restricting construction of multi-storied building in earthquake-prone areas.
b. Using very light material for construction of houses in these areas.
c. Constructing houses to ensure stability.
d. Providing basic amenities to the quake-affected areas.
e. Disconnecting power supply in the event of an earthquake. Remedies during natural disasters - With the help of your teacher, make a list the flood affected places in India.
Answer: The flood affected places in India are West Bengal, Andhra Pradesh, Orissa, Kerala, Haryana, Assam and Uttar Pradesh. Flood prone areas in India are in the areas beside the major rivers like Ganga, Yamuna, Mahanadi, Teesta, Brahmaputra etc. India is one of the most natural disaster prone countries in the world.
Some more Questions.
Fill in The blanks- Naturally-occurring destructive incidents resulting in loss of human life and property are called Natural disasters.
- When there is heavy rainfall and excessive melting of ice, the volume of water increases in the river.
- Land mass sliding down the slopes from mountains or hills are called land slide.
- Landslides are common in the mining areas.
- The erosion of land by the waves in the coastal areas is called coastal erosion.
- Vibration or movement of the upper layers of the earth due to the pressure created inside is called Earthquake.
Answer the following Questions. - What are the preventive measures for cyclones?
Answer: The preventive measures can be taken for cyclones are,
a. Evacuation of people from low-lying areas.
b. Ready to keeping generators, boats, helicopters and other transport facilities.
c. Re-routing trains and buses from the cyclone-prone areas.
d. Keeping people constantly informed about the movement of the cyclone.
e. Keeping the army battalions ready.
f. Ready to keeping food, potable water and clothes ready.
g. Ready to keeping medicines and medical facilities ready. - What are the Effects of floods?
Answer: The Effects of floods are as follows.
a. Floods are causes, loss of shelter, property, land and crops of the people.
b. Telecommunication, electricity supply and transport facilities get affected.
c. Besides washing away the fertile upper layers of soil, a lot of trees are destroyed.
d. Stagnant water in the low lands leads to dangerous diseases. - Mention the Flood control measures.
Answer: The Flood control measures are,
a. To control floods, bunds should be constructed on either side of rivers.
b. Constructing dams across rivers, collecting water in reservoirs and directing the water to other places.
c. Establishing centers to issue flood warnings.
d. Afforestation in the river basins will prevent soil erosion, and also reduce accumulation of silt in the rivers there by reducing the chances of floods. - What are the causes for Landslides?
Answer: The causes for Landslides are,
a. In the mountainous areas and coasts, constantly flowing water and tides remove soil creating slopes leading to landslides.
b. When railways, roads and canals are constructed in the steep mountainous areas, the slopes become steeper leading to landslides.
c. Collection of loose soil on clay soil layer can enhance steep slope formation leading to landslide.
d. Landslides are common in the mining areas. Excavation of earth to reach the ore deposits deep down can cause landslides.
e. Deforestation and deep tilling of the slopes can cause landslides. - What are the effects of Landslides?
Answer: The effects of Landslides are,
a. Flowing small rivers are checked by landslides.
b. Transportation is affected.
c. Streams and many plants get submerged.
d. Landslides can cause loss of life and damage to property. - Mention two effects of Coastal Erosion
Answer: The two effects of Coastal Erosion are,
a. Large amount of land mass submerg into the sea due to coastal erosion by waves.
b. Many houses and also property get loss and damaged. - What are the reasons for earthquake?
Answer: The reasons for earthquake are,
a. Pressure increases in the interior of the earth.
b. Change in the Magma from one part to another.
c. Urbanisation.
d. Deforestation, Construction of Dams, Mining activities etc., - Mention the places of India which earthquakes are happened?
Answer: The occurrence of earthquakes is fairly widespread. The northern Himalayas, East Assam, Gujarat in the West have witnessed most of the earthquakes. In South India, Koyna, Latur and other places have experienced some earthquakes. - What are the measures can be taken in the case of Natural disasters?
Answer: Distribution of food, drinking water, distribution of medicine, temporary shelter facilities, necessary basic amenities, essential services to be provided in the case of Natural disasters.
