Question

Mapping India’s Mountain Ranges: Significance and Impact on Weather

India is home to several mountain ranges that play a critical role in shaping the country’s climate, influencing weather patterns, and supporting biodiversity. These mountain ranges are spread across different parts of the country, each having its unique geographical significance and climatic impact.

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1. Major Mountain Ranges of India

a) The Himalayas

• Location: Extends across northern India, Nepal, Bhutan, and Pakistan.
• Length: ~2,400 km.
• Average Elevation: 6,000 meters.
• Significance:
  • The Himalayas act as a natural barrier to cold winds from Central Asia, protecting the Indian subcontinent from extreme cold in winter.
  • They are the source of major river systems like the Ganges, Yamuna, Brahmaputra, and Indus, supporting agriculture and water supply in northern India.
  • The Himalayas are home to some of the world’s tallest peaks, including Mount Everest and Kanchenjunga.
  • Biodiversity hotspot: Rich flora and fauna, including endangered species like the snow leopard, red panda, and Himalayan black bear.
• Impact on Weather:
  • The Himalayas block the cold winds from Central Asia during winter, preventing them from reaching the Indian plains and keeping the northern parts of India warmer.
  • They play a crucial role in the Indian monsoon system. The mountains trap the moist winds from the Indian Ocean, forcing them to rise and causing rainfall over the Indo-Gangetic plains.
  • In the rain shadow regions (such as Leh-Ladakh), the Himalayas block monsoon rains, leading to arid conditions.

b) The Western Ghats

• Location: Runs parallel to the western coast of India, extending from Gujarat to Tamil Nadu.
• Length: ~1,600 km.
• Average Elevation: 1,200 meters.
• Significance:
  • Declared a UNESCO World Heritage Site for its rich biodiversity.
  • Known for being one of the eight biodiversity hotspots in the world, with a wide variety of endemic species of flora and fauna.
  • Provides the source for several rivers, including the Godavari, Krishna, and Kaveri.
• Impact on Weather:
  • The Western Ghats significantly influence the Southwest Monsoon. Moist winds from the Arabian Sea are forced to rise over the Ghats, resulting in heavy rainfall on the western side (the windward side), which includes regions like Kerala and Karnataka.
  • The eastern side (the leeward side) of the Ghats, including Tamil Nadu and parts of Karnataka, receives less rainfall and falls in the rain shadow region.

c) The Eastern Ghats

• Location: Runs parallel to the eastern coast of India, extending from Odisha to Tamil Nadu.
• Length: ~1,750 km.
• Average Elevation: 600 meters.
• Significance:
  • Not as continuous as the Western Ghats, with hills interspersed by rivers like the Mahanadi, Godavari, and Krishna.
  • Rich in minerals such as bauxite and coal, making the region important for mining industries.
• Impact on Weather:
  • The Eastern Ghats receive moderate rainfall during the Southwest Monsoon, but their effect on weather is less significant compared to the Western Ghats.
  • The Eastern Ghats also receive rainfall during the Northeast Monsoon, which is crucial for Tamil Nadu's agriculture.

d) Aravalli Range

• Location: Spans Rajasthan, Haryana, and Gujarat.
• Length: ~800 km.
• Average Elevation: 600 meters.
• Significance:
  • One of the oldest mountain ranges in the world, rich in minerals such as marble, copper, and zinc.
  • Acts as a physical barrier preventing the expansion of the Thar Desert eastward into the fertile plains of Rajasthan.
• Impact on Weather:
  • The Aravalli Range has limited impact on monsoon winds but helps prevent desertification by acting as a barrier to the Thar Desert.
  • The range receives very little rainfall and is located in a semi-arid zone.

e) The Satpura and Vindhya Ranges

• Location: Central India, spanning Madhya Pradesh, Maharashtra, and Gujarat.
• Length: ~1,200 km.
• Average Elevation: 900 meters.
• Significance:
  • Forms a natural divide between Northern India and Southern India.
  • Home to dense forests and wildlife, including Pachmarhi Biosphere Reserve.
• Impact on Weather:
  • Acts as a barrier to the Southwest Monsoon, helping central India receive rainfall.
  • The ranges also play a role in the distribution of river systems such as the Narmada and Tapti.

f) The Karakoram Range

• Location: Extends across northern India, Pakistan, and China.
• Significance:
  • Home to K2, the second-highest peak in the world.
  • The Siachen Glacier, located in the Karakoram Range, is the largest glacier outside the polar regions.
• Impact on Weather:
  • The Karakoram Range experiences extreme cold weather and heavy snowfall, influencing the glaciers that provide water to the rivers of northern India.
  • Plays a limited role in monsoon activity due to its location beyond the Himalayas.

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2. Impact of Mountain Ranges on India’s Climate

• Monsoon Regulation:

  • The Himalayas and Western Ghats are critical in regulating the Indian monsoon system.
  • The Himalayas block the cold Siberian winds from reaching India, while they trap the Southwest Monsoon winds, causing heavy rainfall in northern India.
  • The Western Ghats cause orographic rainfall on their western slopes, significantly affecting the climate and agriculture in Kerala and Karnataka.

• Rain Shadow Effects:

  • The Western Ghats create a rain shadow region on the eastern side, resulting in much drier conditions in parts of Tamil Nadu and Karnataka.
  • Similarly, the Himalayas create arid conditions in Leh-Ladakh due to their blocking of the monsoon winds.

• Temperature Moderation:

  • The Himalayas moderate the temperature in northern India, keeping it cooler in summer and preventing extreme cold from entering during the winter.
  • In contrast, the Aravalli Range prevents the expansion of the Thar Desert, thereby controlling temperature extremes in nearby regions.

Answer 1

Statement-Based MCQs on India’s Mountain Ranges

1. Consider the following statements about the Himalayas:

1. The Himalayas act as a barrier preventing the cold winds from Central Asia from reaching India during winter.
2. The Himalayas are the source of major river systems in India, including the Ganges, Yamuna, and Brahmaputra.
3. The rain shadow region of the Himalayas experiences heavy rainfall during the monsoon season.

Which of the above statements is/are correct?

a) 1 and 2 only
b) 1 and 3 only
c) 2 and 3 only
d) 1, 2, and 3

Answer: a) 1 and 2 only
Explanation: The rain shadow regions of the Himalayas, such as Leh-Ladakh, are arid and receive very little rainfall.

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2. Consider the following statements about the Western Ghats:

1. The Western Ghats are recognized as a UNESCO World Heritage Site due to their rich biodiversity.
2. The Western Ghats cause heavy rainfall on the eastern side during the Southwest Monsoon.
3. The Western Ghats are the source of major rivers such as the Godavari, Krishna, and Kaveri.

Which of the above statements is/are correct?

a) 1 and 3 only
b) 1 and 2 only
c) 2 and 3 only
d) 1, 2, and 3

Answer: a) 1 and 3 only
Explanation: Statement 2 is incorrect because the Western Ghats cause heavy rainfall on the western side, not the eastern side.

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3. Consider the following statements about the Aravalli Range:

1. The Aravalli Range is one of the oldest mountain ranges in the world, rich in minerals like marble and zinc.
2. The Aravalli Range plays a crucial role in preventing the expansion of the Thar Desert.
3. The Aravalli Range causes heavy rainfall in Rajasthan during the Southwest Monsoon.

Which of the above statements is/are correct?

a) 1 and 2 only
b) 1 and 3 only
c) 2 and 3 only
d) 1, 2, and 3

Answer: a) 1 and 2 only
Explanation: The Aravalli Range does not cause heavy rainfall. In fact, the region receives limited rainfall.

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Match the Following MCQs

1. Match the following mountain ranges with their significance:

Mountain Range	Significance
1. Himalayas	a) Prevents desertification
2. Western Ghats	b) Causes heavy rainfall on the western coast
3. Aravalli Range	c) Acts as a barrier to cold winds from Central Asia
4. Eastern Ghats	d) Home to rich mineral resources like bauxite

Options:
a) 1-c, 2-b, 3-a, 4-d
b) 1-a, 2-d, 3-b, 4-c
c) 1-b, 2-a, 3-d, 4-c
d) 1-c, 2-a, 3-d, 4-b

Answer: a) 1-c, 2-b, 3-a, 4-d