Lesson.12 Climate and Natural Vegetation of India
Lesson.12 Climate and Natural Vegetation of India
I. Choose the Correct Answer:
1. Western disturbances cause rainfall in ________.
- Madhya Pradesh
Ans : Punjab
2. ________ helps in quick ripening of mangoes along the coast of Kerala and Karnataka.
- Mango showers
- Jet stream
Ans : Mango showers
3. ________ is a line joining the places of equal rainfall.
Ans : Isohyets
4. Climate of India is labelled as ________.
- Tropical humid
- Equatorial Climate
- Tropical Monsoon Climate
- Temperate Climate
Ans : Tropical monsoon climate
5. The monsoon forests are otherwise called as ________.
- Tropical evergreen forest
- Deciduous forest
- Mangrove forest
- Mountain forest
Ans : Deciduous forest
6. Sesahachalam hills, a Biosphere reserve is situated in ________.
- Tamil Nadu
- Andhra Pradesh
- Madhya Pradesh
Ans : Andhra Pradesh.
7. ________ is a part of the world network biosphere reserves of UNESCO
- Great Nicobar
Ans : Nilgiaris
II. Match the following:
|1. Sundarbans||Desert and semi desert vegetation|
|2. Biodiversity hotspot||October – December|
|3. North east monsoon||Littoral forest|
|4. Tropical thorn forests||West Beangal|
|5. Coastal forests||The Himalayas|
|Ans : 1 – D, 2 – E, 3 – B, 4 – A, 5 – C|
III. Consider the given statements 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 keep the Indian Sub-continent warm.
- Both (A) and (R) are true: R explains A
- Both (A) and (R) are true: R does not explain A
- (A) is true (R) is false
- (A) is false (R) is true
Ans : Both (A) and (R) are true; R explains A
IV. Choose the inappropriate answer:
1. Tidal forests are found in and around ________.
- The deltas of Ganga and Brahmaputra
- The delta of Godavari
- The delta of Mahanadhi
Ans : Desert
2. Climate of India is aff ected by ________.
- Latitudinal extent
- Distance from the sea
Ans : Soil
V. Answer briefly:
1. List the factors affecting climate of India.
The climate of India is affected by the following factors
- Distance from the seas,
- Monsoon wind
- Relief features
- Jet stream.
2. What is meant by ‘normal lapse rate’?
The temperature decreases when the altitude increases. The temperature decreases at the rate of 6.5 C for every 1000 metres of ascent. This is known as ‘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 shift of the subtropical 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 word ‘monsoon’ is derived from the Arabic word ‘Mausim’ which means season.
- Originally this word was used by the Arab navigators several centuries ago.
- It is used to describe a system of seasonal reversal of winds along the shores of the Indian Ocean especially over the Arabian sea.
- It blows from the South-west to North-east during summer and from the North-east to South-west during winter.
5. Name the four distinct seasons of India.
The four distinct seasons of India arez Winter or Cold weather season
- Pre Monsoon or Summer or Hot weather season
- South-west monsoon or Rainy season
- North-east monsoon season.
6. What is ‘burst of monsoon’?
- The sudden approach of monsoon wind over South India with lightning and thunder is termed as the ‘Break’ or ‘Burst of monsoon’.
- It lowers the temperature of India to a large extent.
- The monsoon wind strikes against the Southern tip of Indian land mass and get divided into two branches namely the Arabian Sea branch and Bay of Bengal branch.
7. Name the areas which receive heavy rainfall.
The heavy rainfall areas of India are
- The Western Coast
- South Meghalaya
- Tripura, Nagaland
- Arunachal Pradesh
8. State the places of mangrove forests in India.
- These forests occur in and around the deltas, estuaries and creeks prone to tidal
- The delta of the Ganga-Brahmaputra has the largest mangrove forest.
- Mangrove forests are also found in the deltas of Mahanadi, Godavari and Krishna rivers.
9. Write any five biosphere reserves in India.
- Gulf of Mannar – Tamil Nadu
- The Nilgiris – Tamil Nadu
- Agasthyamalai – Kerala
- Sundarbans – West Bengal
- Cold desert – Himachal Pradesh
VI. Distinguish between the following
1. Weather and Climate
|1. Weather is the state of the atmosphere at a particular place and time.||Climate is the average of weather for a long period of time at any place.|
|2. Weather of a place many change daily.||Climate of a place remains for a long period of time|
|3. On a particular day, the temperature of Mumbai and Pune may be same.||Generally, the climate of Mumbai and Pune considerably differ.|
2. Tropical Evergreen Forest and Deciduous Forest.
|1. These forests are found in the region where the annual rainfall is more than 200 cm.||These forests are found in the area where the annual rainfall is between 100 cm and 200 cm.|
|2. The trees found in this forest never shed their leaves.||The trees in this forest shed their leaves during spring and early summer|
|3. This forest is also called as Evergreen forest.||This forest is also known as Monsoon forest.|
3. North East Monsoon and South West Monsoon.
|North-east monsoon||South-west monsoon|
|1. This monsoon winds blow from the land to sea.||These winds blow from the sea to land.|
|2. This monsoon winds are the retreat (coming back) winds of Southwest monsoon.||South-west monsoon originate from Indian ocean.|
|3. The period of the North-east monsoon is from October and November.||The period of South-west monsoon is from June to September.|
|4. It gives rainfall only to Coromandal coast.||It gives heavy rainfall to most of the parts of India.|
VII. Give Reasons:
1. Western Coastal plain is narrow.
- Western Coastal Plain lies between the Western Ghats and the Arabian Sea.
- The distance between Arabian Sea and the Western Ghats is less. So, the width of
the coastal plain is narrow.
2. India has a tropical monsoon climate.
- High temperatures during summers and dry winters are some of the characteristics of the Tropical Monsoon types of climate.
- India has a tropical monsoon climate because most of India lies in the tropical belt.
3. Mountains are cooler than the plains.
- The temperature decreases when the altitude increases.
- Temperature decreases at the rate of 6.5 C for every 1000 metres of ascent.
- So, the places in the mountains are cooler than the places on the plains.
VIII. Answer in detail:
1. Write about South West Monsoon.
- The Southwest monsoon is the most significant feature of the Indian climate.
- The onset of the monsoon takes place normally by the first week of June and 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 ‘Burst of monsoon’.
- It lowers the temperature of India to a large extent. The monsoon wind strikes
against the Southern tip of Indian land mass and gets divided into two branches.
i) Arabian sea branch
ii) Bay of Bengal branch
i) Arabian sea branch:
- The Arabian Sea branch of Southwest monsoon given heavy rainfall of the West
coast of India as it is located in the windward side of the Western Ghats.
- The other part which advances towards North is obstructed by Himalayan mountains and results in heavy rainfall in North.
- As the Aravalli Mountain is located parallel to the wind direction, Rajasthan and
Western part do not get much rainfall from this branch.
ii) Bay of Bengal branch:
- The wind from Bay of Bengal branch moves towards North-east India and Myanmar.
- This wind is trapped by a chain of mountains and gives heavy rainfall to the Eastern states.
- Later on, this wind travel towards West which results in decreases in rainfall from east to West.
2. Describe the forests of India.
The climate, soil and landform characteristics are the important environment controls of natural vegetation. On the basis of the above factors, the natural vegetation of India can be divided in to the following types.
Tropical evergreen forest:
- These forests are found in the region where the annual rainfall is more than 200 cm
- Karnataka, Kerala, Andaman-Nicobar islands, Assam, West Bengal and the Eastern states have this type of forests.
- The most important trees of these forests are rubber, mahogany, ebony, rosewood, coconut, chinchona, iron wood and cedar.
- These forests are not fully exploited due to lack of transport facilities.
Tropical Deciduous forest:
- These forests are found in the region with the annual rainfall of 100 to 200 cm.
- Punjab, Haryana, Uttar Pradesh, Bihar, Jharkhand, Madya Pradesh, Chattisgarh, Maharashtra, Karnataka and Telangana states have these forests.
- The most important trees of these forests are sandalwood, rosewood, amla, padauk, bamboo, etc.
- These forests are called as ‘Monsoon forests’.
Tropical Dry forest:
- These forests are found in the areas with 50 to 1oo cm annual rainfall.
- Rajasthan, Haryana, Punjab, Western Uttar Pradesh, Western Karnataka and East Tamilnadu have these forests.
- The important vegetations are amaltas, banyan, bamboo, babool, etc,
- These forests are known as ‘Tropical thorn forest’
- These forests are found in the mountainous ranges. On the basis of altitude and amount of rainfall, these forests are classified in to two.
- They are i) Eastern Himalayan forest and ii) Western Himalayan forest
- The Easter Himalayan forests are found on the slopes of the mountains of Northeastern states.
- The Western Himalayan forests are found in the states of Jammu and Kashmir,
Himachal Pradesh and Uttarakhand.
- Alpine forests are found in the slopes of Himalayas with about 2400 m altitude.
- Tidal forest found in and around the deltas and estuaries. These forests are known as ‘Sundarbans’.z Coastal forests or Littoral forests found along the coasts of Kerala and Goa.
- These forests are found along the rivers on Khadar areas.
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