Geography: India & Physiography

INDIA & PHYSIOGRAPHY:

India with an area of 32,87,263 sq. kms, is the 7th largest countries in the world. Lying entirely in the northern hemisphere. The Tropic of Cancer (23°30'N) passes almost halfway through the country (Figure 7.2). From south to north, India extends between 8°4'N and 37°6'N latitudes. From west to east, India extends between 68°7'E and 97°25'E longitudes.

The longest distance from north to south, is 3214 kms and 2933 kms from east to west. India, a subcontinent, has a land frontier of 15,200 kms and a coastline of 7516.6 kms (including island coastline). Southern most point Indira point or Pygmalion Point (Andaman and Nicobar Island) 64°5'N

The land mass of India has an area of 3.28 million square km. India’s total area accounts for about 2.4 per cent of the total geographical area of the world.

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.

India shares its land boundaries with Pakistan and Afghanistan in the northwest, China (Tibet), Nepal and Bhutan in the north and Myanmar and Bangladesh in the east. Our southern neighbours across the sea consist of the two island countries, namely Sri Lanka and Maldives. Sri Lanka is separated from India by a narrow channel of sea formed by the Palk Strait and the Gulf of Mannar while Maldives Islands are situated to the south of the Lakshadweep Islands.

Boundary Lines:

1. Durand Line: Pakistan and Afghanistan
2. Mac Mohan Line: India and China
3. Radcliff Line: India and Pakistan

India is a vast country. For administrative purposes, the country is divided into 28 States and 7 Union Territories. Delhi is the national capital. The states have been formed mainly on the basis of languages. Rajasthan is the largest state and Goa is the smallest state in terms of area.

MAJOR PHYSIOGRAPHIC DIVISIONS:
The physical features of India can be grouped under the following physiographic divisions
(i) The Himalayan Mountains
(ii) The Northern Plains
(iii) The Peninsular Plateau
(iv) The Indian Desert
(v) The Coastal Plains
(vi) The Islands

The Himalayan Mountains:
These mountain systems are one of the youngest of Fold Mountains in the world, characterised by its youthfulness, tectonic origin, great erosive capacity. Northern mountain consists of Himalayan ranges and trans himalaya which lies north of the great Himalayas. Karakoram , ladak and zaskar ranges are the part of trans Himalayas. Mt. K2 (Godwin Austin) the highest mountain in India is situated on the karakoram range. These ranges converge on the Palmir plateau.

The Northern Plains:

It is formed by the sediments brought by rivers from the Northern and southern side covers an area of 7.5 lakhs sq. km and extends from Punjab to Assam.

Bhabar: These are porous and gravel ridden plain at the foothills of Himalaya. Streams disappear in this area except in the monsoon season.

Terai: The streams reappear in this area and are poorly drainded and forested Bhangar: The term used to refer older alluvium in the river beds Khader: It refers to the new alluvium in river beds in low lying zones.

North Indian plains have highly fertile soils, perennial water source and a good clime suited for agriculture. Although the North Indian plains cover 30% of the geographical area of India, it supports 40% of its population.

Peninsular Plateau:

It is the oldest part of India known as the Indian Plate. This division covers whole of the peninsula in the form of an irregular triangle. The peninsular plateau can be sub divided into the following:

1. Aravallis are relict mountains lie to the north west of the peninsula. These are highly eroded and deeply worn down. Mt. Abu is an important peak of Aravallis.
2. Bundelkhand lies in the east of Aravallis, formed by the erosion of gneisses and quartizites which offers the natural sites for water storage.
3. Malwa is drained by chambal and betwa
4. Vindhyan Kaimur range is a escarpment between Narmada and son valleys.
5. Chhotanagpur plateau is the mineral rich area in India in the east of the son river
6. Shillong Plateau is the continuation of the Deccan Plateau
7. Deccan plateau is an elevated tableland consisting of horizontal lava beds and has a homogeneous sloping towards east and south east.
8. Karnataka Plateau composed of gneisses and schists and the two main sub divisions are Malnad and Maidan.
9. Western Ghats: It is also known as sahyadris stretch continuously to the southern tip have a general altitude 900-1100 kms. Dodabetta (2637m) is the highest peak inthe Nillagiri range. Anaimudi (2695 m) in annamalai is the highest peak in South India.
10. Eastern Ghats are broken hills with no well defined structure. The eatern ghat are called northern hills in the northern sector , cudappah ranges in the middle sector and Tamil nadu hills in the southern sector.

The Indian Desert:

The Indian desest lies towards the western margins of the Aravali Hills. It is an undulating sandy plain covered with sand dunes. This region receives very low rainfall below 150 mm per year. It has arid climate with low vegetatin cover. Streams appear during the rainy season. Soon after they disappear into the sand as they do not have enough water to reach the sea. Luni is the only large river in this region. Barchans (crescent shaped dunes) cover larger areas but longitudinal dunes become more promiment near the Indo-Pakistan boundary. If you visit Jaisalmer, you may go to see a group of barchans.

Coastal Plains:

This is the region between the coast and mountain ranges of the peninsular plateau. This can be divided into western and eastern coast. With the exception of Gujarat, the western coast is narrower than the eastern coast. It has characteristic lagoons or backwaters called kayals such as Asthamudi and vemband in the southern most stretch. The eastern coast has developed deltas of major rivers following through it.

The Islands:

India has 247 islands of which 204 lie in the Bay of Bengal and the remaining in the Arabian sea and gulf of mannar. The Andamans and the Nicobars form two major groups in Bay of Bengal Group. These 2 major groups are separated by Ten degree channel which 121 km wide. This chain of islands are formed by the submergence of Arakan Yoma ranges . The Barren and Narcondam islands , situated north of Port Blair , are volcanic islands. Lakshadweep islands are a group 27 of coral origin and are surrounded by fringing reefs with a total area of only 32 square kilometers. The pamban island , situated between India and Sri Lanka , has a rocky surface, is an extension of the peninisular surface in Ramnad district of Tamil Nadu.

INDIAN VULCANICITY: At present no active volcanoes except on the Barren Island (A/N Islands).

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