IMPORTANT NOTES ON GEOGRAPHY ON DEMAND OF STUDENTS DATE: 18.09.2015

What is the latitudinal and longitudinal extent of the mainland?

Ans:
The latitudinal and longitudinal extent of the mainland is about 30°. Despite this fact the east-west extent appears to be smaller than the north-south extent.
Why is time along the Standard Meridian of India passing through Mirzapur taken as the standard time?

Ans:
From Gujarat to Arunachal Pradesh there is a time lag of two hours. Hence, time along the Standard Meridian of India (82°30′E) passing through Mirzapur (in Uttar Pradesh) is taken as the standard time for the whole country.
 How is India connected to the world through the sea routes?

Ans:
The Trans Indian Ocean routes which connect the countries of Europe in the West and the countries of East Asia provide a strategic central location to India. Note that the Deccan Peninsula protrudes into the Indian Ocean, thus helping India to establish close contact with West Asia, Africa and Europe from the western coast and with Southeast and East Asia from the eastern coast.
How has the opening of the Suez Canal helped in reducing India’s distance from Europe?

Ans:
Since the opening of the Suez Canal in 1869, India’s distance from Europe has been reduced by 7,000 km.
 How has land routes contributed in the exchange of ideas and commodities since ancient times?

Ans: The land routes have contributed in the exchange of ideas and commodities since ancient times. The ideas of the Upanishads and the Ramayana, the stories of Panchtantra, the Indian numerals and the decimal system thus could reach many parts of the world. The spices, muslin and other merchandise were taken from India to different countries. On the other hand, the influence of Greek sculpture, and the architectural styles of dome and minarets from West Asia can be seen in different parts of India.

Q11. The central location of India at the head of the Indian Ocean is considered of great significance. Why? Ans:

 The central location of India at the head of the Indian Ocean is considered of great significance because of the following reasons: (a) India is centrally located on the world map. (b) India has longest coastline on the Indian Ocean. (c) It is surrounded by three water bodies, in the south by the Indian Ocean, in the east by the Bay of Bengal and in the west by the Arabian Sea. (d) India is strategically located at the centre of the trans-Indian Ocean routes which connect the European countries in the west and the countries of East Asia. Thus, India could establish close contact with West Asia, Africa and Europe from the western coast. Moreover, it could establish close contact with Southeast and East Asia from the eastern coast. (e) Ocean sea routes, i.e., Suez Canal route, Cape of Good Hope route, pass through the Indian Ocean. (f) India has been able to establish close cultural and commercial contacts with countries of west and east due to its central location.

Why 82°30'E has been selected as the Standard Meridian of India? 

Answer:

 India lies to the east of the Prime Meridian between 68°7’ to 97°25’E Longitude which makes a vast longitudinal extent of India about 30°.

This accounts for a time lag of two hours in local time between its eastern (Arunachal PRadesh) and western extents(Gujarat). 

82°30' E meridian divides the two hour lag from west to east into one hour by passing through mirzapur in Uttar pradesh. This meridian has been accepted as the Indian Standard Time (IST) throughout the country.

 

 

  Why Indian Ocean named after country, India? Give reasons.

Answer
The Indian Ocean named after country, India because:
→ No other country has a long coastline on the Indian Ocean as India has.
→ The central location of India at the head of the Indian Ocean has provided India a strategic location of great significance along the trans-Indian Ocean route. It is India’s eminent position in the Indian Ocean which justifies the naming of the ocean after India.

COASTAL PLAINS AND ISLANDS

India – 6,100 km length of coastline.
•Extends from Kachchh in Gujarat in the west to the Gangetic delta in the east.
•Coast of India is divided into Western Coastal plain and Eastern Coastal plain.
•Western coastal plain lies between Western Ghats and the Arabian sea & extends from Gulf of Kachchh in the north to Cape Comorin (Kanyakumari) in the south to the length of about 1,500 km.
•It is divided into Malabar Coast, Karnataka (Canara) coast, Konkan coast, Gujarat coast, Kachchh & Kathiawad peninsulas.
•Coast is straight and affected by the South-West Monsoon winds.
•So there are only few good harbours.
•Important Ports -Kandla, Mumbai, Nhava-Sheva, Marmagoa. Karwar, Mangalore, Kochi
•Eastern coast extends from Kanyakumari to the Gangetic delta & between Eastern Ghats and Bay of Bengal.
•It constists of the deltas of rivers Mahanadhi, Godavari, Krishna, Kaveri.
•It is broad & flat land.
•There are some salt water lakes or lagoons
•Chilka lake of Orissa, Pulicat Lake of Tamilnadu

•Ports in Western Coast – Cambay, Kandla, Surat, Mumbai, Goa, Karwar, Mangalore, Kozhikode (Calicut), Cochin, Trivandrum, and ancient port of Muziris (Kranganore)
•Eastern coast ports – Tamluk , Kolkotta, Paradeep, Vishakapattanam, Chennai, Pondicherry & Tuticorin.

 

 

NORTH INDIAN RIVERS

•Mostly rise in the Himalayan mountains
•Are snowfed & rainfed
•Perennial in character
•There are 3 river systems in North India.
•Indus, Ganges, Brahmaputra

RIVER GANGES AND ITS TRIBUTARIES

The Ganga, famous alike in legend and history, is considered the most sacred river by the Hindus. It covers, what is called the heartland of India, which was the main centre of the ancient Aryan culture.

It rises near the glacier, Gangotri in the Himalayas and flows through Uttar Pradesh, Bihar and Bengal to fall into the Bay of Bengal. Gangaand its tributaries Jamuna, Gornti, Garga, Sarda, Gandak, Chambal, Son and Kosi, spread out like a fan in the plain of India thus forming the largest river basin in India, with an area, one quarter of the total area of India.

•The Indus, which the Aryans called the Sindhu, has lent its name to India.
•Its valleys on both sides have been the seat of a civilization.

•The Brahmaputra rising in western Tibet, flows for some 1300 km through the Himalayas, then turns south-west and then south, joining the easternmost branch of the Ganga the Padma and empties together with Ganga into the Bay of Bengal.
•The rivers of Deccan denuding their beds for long geological ages have developed flat valleys with low gradients. The major Deccan rivers are the Godavari, the Krishna, the Cauvery, the Pennar, the Mahanadi, the Damodar, the Sharavati, the Netravati, the Bharatapuzha, the Periyar, the Pamba, the Narmada and the Tapti.
•These rivers are entirely rain-fed with the result that many of them shrink into rivulets during the hot season. The Deccan rivers contribute about 30% of the total outflow in India. Of this, the rivers that flow from west to east account for 20% and those from east to west about 10%

SOUTH INDIAN RIVERS

•Rain fed
•Flow only during the rainy season.
•Dry in summer
•Seasonal rivers and dams are constructed across them to store water.
•Since they flow on the slopes of the ghats, they have many waterfalls.
•Helpful in generation of hydro-electricity .

 
Q.5: Give any four characteristics of Ganga-Brahmaputra Delta.
Ans: Normally Delta is a triangular shaped land which is formed by the deposition of sediments at the mouth of a river. Some of the characteristics of the Ganga-Brahmaputra delta are as follows -
=> It is the largest delta in the world.
=> It is not only well-watered but also, highly fertile land-form.
=> The Brahmaputra after joining the Ganga becomes sluggish. Due to the gentle slope, islands of mud and silt develop in its channel and in order to circumvent these obstructions it splits into a number of channels. This process is going on continuously and as a result of which it has become the fastest growing delta in the world.
=> The lowest part of the delta has become marshy owing to the free mingling of river and sea waters by the high and low tides.

Q.9: Distinguish between
(i) Converging and diverging tectonic plates.
(ii) Bhangar and Khadar
(iii) Western Ghats and Eastern Ghats.
Ans:

(i) Converging and diverging tectonic plates.

 (i) The internal heat of the earth makes the molten rocks to rush towards the surface of the earth and drive the crust into large fragments known as “Tectonic Plates”. These plates are drifting oven the mantle of the earth. As a result when the two or more plates are pushed towards each other they are called ‘Converging Plates’. On the other hand if they are moving away from each other, they are called ‘Diverging Plates’.
(ii) According to the age of the soils of the Northern Plain they have been differentiated by two names: (a) Bhangar and (b) Khadar. The difference between these two are mentioned below –
(a) Bhangar - These are the older alluvium or old soil and form the largest part of the Northern Plains. They lie above the flood plains of the rivers and present a terrace like structure. It often contains Kankar nodules made of calcareous deposits.(b) Khadar - The newer and younger deposits of the flood plains are known as ‘Khadar’. So, these are the new alluvium or new soil and are very fertile. Thus, Khadar is ideal for intensive agriculture

 

(iii)
Western Ghats
1. The Western Ghats are situated and mark the western edges of Deccan Plateau parallel to the western coasts of India along the Arabian Sea.
2. Continuous, can be crossed through the passes only.
3. The Western Ghats are higher than the Eastern Ghats. Average elevation is 900 - 1600 meters.
4. The height increases progressively from north to south. The highest peaks include the Anai Mudi, the Doda Belta.
5. The Western Ghats enclose a narrow strip between its western slopes and the Arabian Sea which is known as Western Coastal Plain. Its maximum width is 64 km.
6. It experiences orographic rain mostly in summer due to the summer monsoons. The climate is hot and moist.
7. Here the soil is highly fertile. Rice, spices, rubber and fruits like coconuts, cashew nuts etc. are grown here. 

 

EASTERN GHATS:
1. The Eastern Ghats are situated and mark the eastern edges of Deccan Plateau parallel to the eastern coasts of India along the Bay of Bengal.
2. Discontinuous, irregular and dissected by rivers draining into the Bay of Bengal.
3. Average elevation is 600 meters.
4. The highest peaks include the Mahendragiri, the Javadi Hills.
5. The Eastern Ghats also enclose a strip of land between its eastern slopes and the Bay of Bengal which is known as the Eastern Coastal Plain. It is wider than the Western Coastal strip with its maximum breadth 120 km.
6. It receives rain both in summer and winter, especially in winter through winter monsoons. However, here the rain is lesser than the western strip.
7. The soil is not as fertile as western strip. Rice, ground nuts, cotton, tobacco, coconuts etc. are grown here.

(b) Bhangar and Khadar
Answer:

(c) Western Ghats and Eastern Ghats
Answer:

Q10. Give an account of the Northern Plains of India.
Answer: The northern plain of India is formed by three river systems, i.e. the Indus, the Ganga and the Brahmaputra; along with their tributaries. This plain is composed of alluvial soil which has been deposited over millions of years. The total area of the northern plain is about 7 lakh square kilometer. It is about 2400 km long. Width is about 240 to 320 km. Northern plains are most densely populated areas of the country. Here, we find alluvial soil, thus making the plain very fertile and agriculturally very productive. Because of the three river systems, i.e. the Indus, the Ganga and the Brahmaputra; along with their tributaries, availability of water is there in abundance through the year.

The northern plain is divided into three sections, i.e. the Punjab Plain, the Ganga Plain and the Brahmaputra Plain.

1. Punjab Plains: The Punjab plains form the western part of the northern plain. This is formed by the Indus and its tributaries; like Jhelum, Chenab, Ravi, Beas and Sutlej. A major portion of this plains is in Pakistan. Doabs are found in Punjab plains.

2. Ganga Plains: This plain extends between Ghaggar and Tista rivers. The northern states, Haryana, Delhi, UP, Bihar, part of Jharkhand and West Bengal in the east lie in the Ganga plains.

3. Brahmaputra Plains: This plain forms the eastern part of the northern plain and lies in Assam.