10th Social Science Geography Solutions Chapter 2 | Climate and Natural Vegetation of India - TEXTBOOK EVALUATION with KEY ANSWERS

 Climate and Natural Vegetation of India

I. Choose the correct answer

 

1.   Western disturbances cause rainfall in _________.

    a) Tamilnadu
    b) Kerala
    c) Punjab
    d) Madhya Pradesh
    Ans: c) Punjab
 

2.   _________ helps in quick ripening of mangoes along the coast of Kerala and Karnataka. 

    a) Loo
    b) Norwester
    c) Mango showers
    d) Jet stream
    Ans: c) Mango showers

 

3.   _________ is a line joining the places of equal rainfall.

    a) Isohyets
    b) Isobar
    c) Isotherm
    d) Latitudes
    Ans: a) Isohyets

 

4.   Climate of India is labelled as _________.

    a) Tropical humid
    b) Equatorial Climate        
    c) Tropical Monsoon Climate
    d) Temperate Climate
    Ans: c) Tropical Monsoon Climate

 

5.   The monsoon forests are otherwise called as _________.

    a) Tropical evergreen forest        
    b) Deciduous forest
    c) Mangrove forest
    d) Mountain forest  
    Ans: b) Deciduous forest

 

6.   Sesahachalam hills, a Biosphere reserve is situated in _________.

    a) Tamil Nadu
    b) Andhra Pradesh
    c) Madhya Pradesh
    d) Karnataka
    Ans: b) Andhra Pradesh

 

7.   _________ is not a part of the world network biosphere reserves of UNESCO

      a) Nilgiri      
b) Agasthiyamalai
c) Great Nicobar
d) Kachch
Ans: d) Kachch

II. Match the following

 

I		II
1.	Sundarbans	a	Desert and semi desert vegetation
2.	Biodiversity hotspot	b	October-December
3.	North east monsoon	c	Littoral forest
4.	Tropical thorn forests	d	West Bengal
5.	Coastal forests	e	The Himalayas

 

I		Answers
1.	Sundarbans	d	West Bengal
2.	Biodiversity hotspot	e	The Himalayas
3.	North east monsoon	b	October-December
4.	Tropical thorn forests	a	Desert and semi desert vegetation
5.	Coastal forests	c	Littoral forest

 

III. Consider the given statement and choose the correct option from the given below ones

  

1.   Assertion (A) : The Himalayas acts as a climatic barrier.

      Reason (R) :  The Himalayas prevents cold winds from central Asia and keeps the Indian Sub-continent warm.(Give option for this question)
a) Both (A) and (R) are true: R explains A
b) Both (A) and (R) are true: R does not explain A
c) (A) is correct (R) is false
d) (A) is false (R) is true
Ans: a) Both (A) and (R) are true: R explains A

IV. Choose the inappropriate answer

  

1.   Tidal forests are found in and around ________.

      a) Desert
b) The deltas of Ganga and Brahmaputra
c) The delta of Godavari
d) The delta of Mahanadhi
Ans: a) Desert

 

2.   Climate of India is affected by__________.

      a) Latitudinal extent
b) Altitude
c) Distance from the sea
d) Soil
Ans: d) Soil

V. Answer briefly

 

1.   List the factors affecting climate of India.

•  Latitude
• Altitude
• Distance from the sea       
• Monsoon wind
• Relief features
• Jet streams

 

2.   What is meant by ‘normal lapse rate’?

• When the altitude increases, the temperature decreases.
• Temperature decreases at the rate of 6.5°C for every 1000 metres of ascent. This is called “Normal lapse rate”.

 

3.   What are ‘jet streams’?

• Jet streams are the fast moving winds blowing in a narrow zone in the upper atmosphere.
• According to the Jet stream theory, the onset of southwest monsoon is driven by the shift of the sub tropical westerly jet from the plains of India towards the Tibetan Plateau.
• The easterly jet streams cause tropical depressions both during southwest monsoon and retreating monsoon.

 

4.   Write a short note on ‘Monsoon wind’.

• The most dominant factor which affects the climate of India is the monsoon wind.
• It is used to describe a system of seasonal reversal of winds along the shores of Indian ocean especially over the Arabian sea.
• It blows from the southwest to northeast during summer and from the north east to southwest during winter.

 

5.   Name the four distinct seasons of India.

• Winter season  - (January - February).
• Summer season - (March - May).
• Southwest monsoon or Rainy season  - (June - September).
• Northeast monsoon season - (October - December).

 

6.   What is ‘burst of monsoon’?

• Prior to the onset of the southwest monsoon, the temperature in north India reaches up to 46°C.
• The sudden approach of monsoon wind over south India with lightning and thunder is termed as the ‘Break’ or ‘Burst of Monsoon’.

 

7.   Name the areas which receive heavy rainfall.

• The Western coast
• AssamSouth Meghalaya    
• Tripura
• NagalandArunachal Pradesh

 

8.   State the places of mangrove forests in India.

• The delta of Ganga - Brahmaputra.
• The deltas of Mahanadi, Godavari, Krishna rivers are also known for Tidal Forests (Mangrove Forests).

 

9.   Write any five biosphere reserves in India.

    Agasthyamalai     - Kerala
    Sundarbans         - West Bengal
    Great Nicobar      - Andaman and Nicobar Islands
    Gulf of Mannar    - Tamil Nadu
    Kachch               - Gujarat

VI. Distinguish between

1.   Weather and Climate

Weather	Climate
Weather refers to the state of atmosphere of a place at a given point of time.	Climate is the accumulation of daily and seasonal weather events of a given location over a period of 30-35 years
Weather of a place may change daily	Climate of a place remains constant over a long period.

 

 

2.   Tropical Evergreen Forest and Deciduous Forest.

Tropical Evergreen Forest	Deciduous Forest
Tropical evergreen forests are found in areas with 200cm or more annual rainfall.	Deciduous forests are found in areas with 100 to 200 cm annual rainfall.
These forests are evergreen and they do not shed their leaves.	The trees in these forests drop their leaves during the spring and early summer.
These forests are found in Maharashtra, Karnataka, Kerala, Andaman-Nicobar islands, Assam and West Bengal.	These forests are found in the Himalayan region from Punjab to Assam, Uttar Pradesh, Bihar, Tamilnadu and Kerala.
Important trees are rubber, mahogany, ebony, rosewood, coconut, bamboo, cinchona and candes.	Important trees are sandalwood, rosewood, kusum, palas, amla, padauk, bamboo etc.

 

 

3.   North East Monsoon and South West Monsoon.

North East Monsoon	South West Monsoon
Northeast monsoon blows during October and November	Southwest monsoon blows from June to September
Northeast monsoon winds blow from land	Southwest monsoon originates from the Indian ocean.
It gives rainfall to coromandal coast	It gives rainfall to the western coastal plain and most other parts of India.
India gets only 25% of rainfall from North east monsoon.	India gets 75% of rainfall from southwest monsoon.

VII. Give reasons for the following topics

1.   Western Coastal plain is narrow.

• The western coast plain is narrow because the rivers flowing through this plain do not form any delta. 
• The coastal plain has sand dunes.

 

2.   India has a tropical monsoon climate.

• India has a tropical monsoon climate because most of India lies in the tropical belt and her climate is influenced by the monsoon winds which mainly blow in the tropics (20°N and 20°S).

 

3.   Mountains are cooler than the plains.

• Mountains are cooler than plains because when the altitude increases, the temperature decreases. 
• Temperature decreases at the rate of 6.5°C for every 1000 metres of ascent.

 

VIII. Answer in detail

 

1.   Write about Southwest Monsoon.

• The southwest monsoon is the most significant feature of the Indian climate.
• The onset of the monsoon takes place normally over the Southern tip of the country by the first week of June.
• It covers the whole country by 15th July.
• Prior to the onset of the Southwest Monsoon, the temperature in North India reaches up to 46°C.
• The sudden approach of monsoon wind over South India with lightning and thunder is termed as the ‘Break’ or ‘Burst of Monsoon’.
• The monsoon wind strikes against the southern tip of Indian land mass and gets divided into two branches.
• They are i) The Arabian sea branch and     ii) The Bay of Bengal branch.

      Arabian sea branch:

• The Arabian Sea branch of Southwest Monsoon gives heavy rainfall to the west coast of India as it is located in the windward side of the Western Ghats. The other part advances towards north.
• It is obstructed by Himalayan mountains and results in heavy rainfall in north. As Aravalli mountain is located parallel to the wind direction, Rajasthan and western part do not get much rainfall.

      Bay of Bengal branch:

• The Bay of Bengal branch moves towards Northeast India and Myanmar.
• The wind is trapped by a chain of mountains like Garo, Khasi and Jainthia. The heaviest rainfall is caused at Mawsynram.
• Later on, this wind travels towards west which results in decrease in rainfall from east to west.

 

2.   Describe the forests of India.

• On the basis of climate, soil and landforms the forest of India can be divided into the following types.
• Tropical Evergreen Forest Tropical Deciduous Forest
• Tropical Dry Forest Mountain (Montane) Forest
• Alpine Forest          Tidal Forest

      Tropical Evergreen Forest:

• Tropical evergreen forests are found in the regions where the annual rainfall is more than 200 cm.
• Areas: Western Ghats in Maharashtra, Karnataka, Kerala, Assam, West Bengal, Nagaland, Tripura, Mizoram and Manipur.
•  Trees found: Rubber, mahogany, ebony, rosewood, coconut, bamboo, cinchona and palm.

      Tropical Deciduous Forest (Monsoon Forest):

• Tropical deciduous forests are found in areas with 100 to 200 of rainfall
•  Areas: Sub Himalayan Region, Great Plains, Central India and South India.
•  Trees found: Sandalwood, rosewood, teak, sal, kusum, mahua, palas, haldu, amla, padauk and bamboo.

      Tropical Dry Forest:

• These forests are found in areas with 50 to 100 cm of rainfall
• Areas: East Rajasthan, Haryana, Punjab, Western Uttar Pradesh, Madhya Pradesh, Eastern Maharashtra,
• Telangana, West Karnataka and East Tamilnadu.
• Trees found: Mahua, banyan, amaltas, palas, haldu, kikar, bamboo, babool and khair.

      Desert and Semi-desert vegetation:

• These are found in the areas having annual rainfall of less than 50 cm.
• These are also called ‘Tropical thorn forests’
•  Areas: West Rajasthan, Haryana, Gujarat and South West Punjab
•  Trees found:  Babul, Kikar and wild palms.

      Mountain or Montane forest

i)    These forests are found in the altitude of 1200 - 2400 m.

      Areas: These are found on the slopes of the mountains in north-east states.

      Trees found: Sal, Oak, Laurel, Amura, Chestnut and Cinnamon

ii)   Upto 900 m altitude semi desert vegetation is found.

      Trees found: Bushes and small trees. Chir is also found

      Alpine Forest:

• Area: All along the Himalayas with 2400 m altitude. Mostly found in the eastern parts of the Himalayas.
• Coniferous trees: Oak, silver fir, pine, juniper

      Tidal Forest:

•  Areas: In and around the deltas and estuaries. Also known as swamp forest or delta forest.
• The delta of the Ganga - Brahmaputra, the deltas of Mahanadi, Godavari and Krishna are known for tidal forest.
• These are also known as mangrove forest.

IX. Map

Mark the following on the outline map of India.

1. Direction of South West Monsoon wind.
2. Direction of North East Monsoon wind.
3. Areas of heavy rainfall.
4. Mountain forests.
5. Panna biosphere reserve
6. Agasthiyamalai biosphere reserve