India: Relief Features

India, the 7^th largest country in the world and it has a vast longitudinal extent. India is located between 687’E and 9725’E. The longitudinal difference between the easternmost (Arunachal Pradesh) and westernmost (Gujarat) limits is approximate 30

As we know that the sun takes 4 minutes to cross 1 longitude. (One rotation completed by earth in 24 hours (1440 min). Total no. of longitudes is 360. Therefore 1440 ÷ 360= 4min)

So, to cross 30 longitudes, it will take 120 minutes or 2 hours.

To avoid confusion of time difference along the longitudes 8230’E is considered as the Standard Meridian of India. Therefore, all the places in India have the same time.

The Great Himalayas are the great climatic moderator for the Indian subcontinent. They act as a barrier against the chilling Arctic winds. They deflect the Arctic winds back to China and Siberia. They also prevent Jetstreams from interfering the climatic conditions of India. Hence, they prevent North India from becoming a cold desert. It also traps the rain-bearing monsoon winds from escaping to the Asia continent and forcing them to rain in India.

Following are the major physiographic divisions of India-

i) The Great Himalayas

ii) The Northern Plains

iii) The Western Desert

iv) The Peninsular Plateau

v) The Coastal Plains

vi) The Island groups

The contrasting features of the Himalayan region and of the Peninsular plateau are as follows-

The Himalayas has a profound influence on Indian agriculture. Following are the ways in which the Himalayas influence Indian agriculture –

a. Rivers – Agriculture is the mainstay of many people living in the northern region. The Himalayas are the source of water to the three major river systems namely, the Indus river system, the Ganga river system and the Brahmaputra river system. These three river systems altogether with numerous tributaries and distributaries have a large catchment area that they drain and provide life-giving water to the people living in the region. The agricultural lands are irrigated by the water of these rivers.

b. Rains – the Himalayas prevent the rain-bearing monsoon winds from escaping to Asia continent by obstructing its path and forcing them to rain in India. Monsoons are the main source of water/irrigation in India. Its failure results in drought and famine in many parts of India.

c. Fertile soil –River originating in the Himalayas carry loads of fertile alluvium while sculpting the valleys in its upper course. These sediments are deposits on the banks of the river when the river enters the plain and thus each year fertile soil deposited by the river which promotes agricultural production in the plain and delta region.

Indo-Gangetic plains are the most populated region of India. There are many factors responsible for it, they are –

a. Perennial supply of water- Availability of water throughout the year make agricultural activities possible all through the year and more than one crop cycle in a year possible to support the population.

b. A strong network of road and rail - Gangetic plains have a strong network of road and rail network that connect it to all the parts of the country. The comparatively flat surface of the Indo-Gangetic plains provides the ideal conditions to construct roads and lay railway lines.

c. Many agro-based industries are located in this region. Providing work to the people and attracting people from other parts in the region.

(i) Mountain and hill ranges –

a. the Karakoram,

b. the Zaskar,

c. the Patkai Bum,

d. Jaintia,

e. the Vindhya range,

f. the Aravali, and

g. the Cardamom hills.

(ii) Peaks –

a. K2,

b. Kanchenjunga,

c. Nanga Parbat and

d. The Anaimudi.

(iii)Plateaus –

a. Chota Nagpur and

b. Malwa

(iv) a. The Indian Desert,

b. The Western Ghats,

c. Lakshadweep Islands

(i) Barren Islands (India)

(ii) Pakistan, Srilanka, Nepal, Bangladesh, Bhutan, Myanmar

(iii) Gujarat, Rajasthan, Madhya Pradesh, Chhatisgarh, Jharkhand, West Bengal, Tripura and Mizoram

(iv) 37⁰6’ N

(v) 8⁰4’ N

(vi) 68°7'E and 97°25'E

(vii) Kanyakumari

(viii) Palk Straits

(ix) Delhi, Chandigarh, Puducherry, Dadra Nagar Haveli, Daman and Diu, Lakshadweep, Andaman and Nicobar.

(x) Himachal pradesh, Uttarakhand, Sikkin, Arunachal Pradesh, Assam, Jammu and Kashmir.

The similarities between the Eastern and Western Coastal plains are as follows –

a. Both of the coastal plains are bordered by the water body.

b. Both are part of the peninsular block.

c. Both lie between the Deccan plateau and the water bodies.

d. Both fall under the same climatic zone.

The points of differences between the two are as follows –

The foremost and primary reason is the soil and relief. The plateau region is the oldest tectonic block of the Indian subcontinent. It has a highly eroded surface and mainly consists of hard rocks. Due to this reason, there is a very thin layer of soil in this region that too is not fertile and lack humus content.

The next important reason is the lack of availability of water throughout the year. The rivers of this region are rain-fed thus in summers they hardly have water to support agriculture in the region.

The importance of Himalayas in the development of India can be mentioned under followings heads -

• Strategic importance: The Himalayas acts as a natural frontier of India against the infiltration from the hostile neighbouring countries (China and Pakistan).

• Climatic importance: The Himalayas prevent northward movement of summer monsoon winds and force them to rain in India. Because of which India receives most of its water needs fulfilled by the monsoon. The Himalayas also acts as a climatic barrier by preventing cold Siberian from entering India and deflect them to China and other parts of Asia continent.

• Physical importance: The glaciers of the Himalayas are the source of water to many perennial rivers of North India. These rivers in their upper course erode the mountain ranges and deposit the alluvial soils when they enter the plains and delta region. The alluvial soil is highly productive and helps in producing the grain to sustain such a huge population.

• Agricultural importance: Rivers that originate in Himalayas deposits a lot of sediment when they enter their middle and mature course. This led to the formation of India’s most fertile agricultural grounds known as Northern Plains. The perennial water of the mighty rivers originating out of the Himalayas is utilized for irrigation, industrial and domestic purpose. Apart from this Himalayan slopes are very well utilised for tea plantation.

• Economic importance: There is huge hydro-electric power potential in the Himalayan region. Many hydroelectric power projects are already developed to satisfy rising power needs. The Himalayas are the source for - timber, medicinal Herbs & plants.