India occupies the south-central peninsula of the Asian continent. Besides the main land, there are two groups of islands, namely Lakshadweep in the Arabian Sea and Andaman & Nicobar Islands in the Bay of Bengal. The mainland of India lies between 8°4’ N and 37°6’ N latitude and 68°7’ E and 97°25’ E longitude. The Andaman and Nicobar islands lie to the south east of the mainland and Lakshadweep to the southwest. A world map showing the location of India is given here 

 Note that the country completely lies in the northern hemisphere. India has a long coastline, extending to about 7,500 km which permits numerous ocean routes to the rest of the world for trade and travel.

India is endowed with almost all the important topographical features, such as high mountains, extensive plateaus, and wide plains traversed by mighty rivers. The country is bounded by Himalayas in the North and has a large peninsular region tapering towards the Indian Ocean. The Himalayas in the north are the major mountain ranges of the world. The other prominent mountains of India include the Aravallis, the Vindhyachals, the Satpuras, the Eastern Ghats, and the Western Ghats. The mountains are the primary source of rivers which derive their flow from rainfall and snow and glacier melt. The plateaus are another striking feature of topography in India and they range in elevation from 300 to 900 m.

With a geographical area of 3,287,263 sq. km, India is the seventh largest country in the world. The countries whose area is larger than India are: Russia, Canada, China, United States of America, Brazil and Australia. India occupies about nearly 2.42% of the land area of the earth. The latitudinal and longitudinal extent of India is almost of the same magnitude in degrees, about 30°. The distance between the extreme north to south tip is about 3,200 km while the east-west extent is 3,000 km. The Tropic of Cancer divides the country into two nearly equal parts. The northern part mainly consists of the Himalayas and the plains of Indus and Ganga. The southern part is of triangular shape.To the north of the mainland of India lies the mountain chain of Himalayas. The word Himalayas is formed by him (snow) with alaya (abode), meaning thereby that Himalayas are the abode of snow. The presence of Himalayas has an important bearing on the climate and water resources of the country.

The major physiographic divisions of India are :

The Himalayas

The Himalayas mountain region extends all along the northern border of the country. From the eastern border of West Pakistan to the frontiers of Burma, the Himalayas run for a distance of about 2,400 km in the east-west direction in the shape of an arc. The width of the mountains varies from 400 km in the west to 150 km in the east. Himalayas cover an area of about 500,000km². The average elevation of the eastern half portion is greater than that of the western half. Mountainous area in India occupies 96.06 M-ha divided into: Himalayas 51.43 M-ha, Vindhya region 9.27 M-ha, Eastern Ghats 18.02 M-ha, Western Ghats 7.74 M-ha, and Satpura Ranges 6.60 M-ha. The area of Himalayas above various contour heights is given in Table 1.

The Himalayas, which are geologically young mountains, consist of three main series running parallel to each other. The northern most range is known as the Great Himalayas or the Himadri. In this range, the average altitude is about 6,000m and this range contains a number of high peaks including the Mount Everest (height = 8,848m) which is the highest peak in the world. This peak is located in Nepal where it is known as Sagarmatha. The second highest peak of Hamalayas is Kanchenjunga (8,598 m) which is the highest peak in India. Other prominent peaks are Nanga Parbat (8,126 m) and Nanda Devi (7,817 m).

The second range, the Middle Himalayas or Himachal, lies to the south of Himadri. Here, the altitude is between 3,700 to 4,500m and the width is about 50 km. Popular hill stations of North India, such as Darjeeling, Dharamshala, Dalhousie, Shimla, and Mussorrie are located in this range. The southern most range is the outer Himalayas or the Shivaliks. Here the altitude ranges from 900 to 1,100m and the width varies between 10 and 15 km. In between the Himachal and Shivalik ranges are plateaus and flat bottom valleys of thick gravel and alluvium. Locally, these are known as duns, e.g., Dehradun.

In the east-west direction, Himalayas can be divided into four parts. The Western Himalayas cover the state of Jammu & Kashmir and a part of Himachal Pradesh. The part between Satluj River and the Kali River is known as Kumaon Himalayas and the Nepal Himalayas lie between the Kali River and the Tista River. The area between the Tista and the Brahmaputra Rivers is known as the Assam Himalayas.

The major rivers of north India that originate from Himalayas are the Indus, Satluj, Ganga, and the Brahmaputra. Being snowfed, these rivers are perennial and carry large amount of water and sediments. The origin of the Indus, the Satluj and the Brahmaputra is near the Kailash Mansarovar region. Besides the snow covered peaks, glaciers and pristine rivers, Himalayas are known for beautiful valleys the world over. The valleys of Kashmir, Kulu, Kangra, and Khasi and Garo hills are known for their scenic beauty and salubrious climate attracting millions of tourists every year.

The Northern Plains

The Himalayas are young mountains and the rivers originating from them carry large volumes of sediments. As these rivers enter plains, their velocity and hence the sediment carrying capacity reduces which forces them to dump the sediment. The north Indian plains of Indus and Ganga were formed by the alluvium that was carried by the rivers originating from Himalayas. This has led to the formation of vast northern plains of thick and fertile alluvium in north India. This coupled with favorable climate and adequate water supply has made this region highly fertile. No wonder that this region was the birthplace of the most ancient and enduring civilization on earth, known as the Indus valley civilization.

 The northern plains extend from the mouths of the Indus in the west to the mouths of the Ganga-Brahmaputra in the east, a distance of about 3,200 km. The width of the plains varies between 300 km to 150 km. The western part of these plains has five rivers – the Indus and its tributaries, the Chenab, the Ravi, the Beas and the Satluj. Locally, the land between two rivers is known as the Doab (Do means two and ab means water). [Readers may recall the equivalent Greek word Mesopotamia, which also means the land between two rivers. The famous Mesopotamian civilization arose in the valley of Euphrates and Tigris, modern Iraq, about 5,000 BC.] By the same analogy, the plain formed by five rivers in north India is known as Punjab (Punj means five). After the partition of India in 1947, a large part of Punjab is now in Pakistan. The plains of Ganga valley can be divided into four parts based on relief. A narrow belt of land near the foot of the Shivaliks is known as Bhabar. Its width is about 8–16 km and it is covered with pebbles. A wet and marshy belt known as the Terai lies south of Bhabar. This belt supports forests and wildlife. The older alluvium of the plain is known as Bhangar. The continuous deposition of alluvium leads to the formation of terrace-like features on the flood plains which are known as Khadar.

The Peninsular Region

This is a triangular shaped region whose vertex is near Kanyakumari at the southern tip and base is near the line joining Calcutta to Saurashtra in Gujarat. In this region, the elevation varies between 300 and 1,800 m. The peninsular region may be further subdivided into two parts: the central highlands and the Deccan Plateau. The northern part of the peninsular region which consists of low mountain ranges and igneous rocks forms the central islands. The north-western part of this area is dotted with very old mountains, known as the Aravallis. The southern boundary of this highland is formed by Vindhyachal mountain range. Further west to Aravallis lies the Thar desert. The Malwa plateau lies between the Aravallis and the Vindhyachal range. The area east to Malwa plateau is known as Bundelkhand. The valley of Narmada River lies to the south of Bundelkhand. To the east of Narmada valley is the Chottanagpur plateau whose major part comes under the newly formed Jharkhand state.

 The southern part of the peninsular region is known as the Deccan plateau which extends southward from the Satpura range. The western boundary of this plateau is formed by a mountain chain known as Western Ghats. This is a low mountain range near the western coast of India. In the Maharashtra state, these mountains are known as Sahyadri, in Tamil Nadu they are known as Nilgiri, and in Kerala they are known as Cardamom hills. The hills near the eastern boundary of the plateau are known as Eastern Ghats. The general slope of the peninsular plateau is towards east as evidenced by the flow direction of major rivers. But the north part of the plateau slopes towards west. 

 The Coastal Plains

The coastal plains lie between the Western Ghats and the Arabian Sea on the west coast and the Eastern Ghats and the Bay of Bengal on the east coast. These are narrow strips of land which are desiccated by a number of rivers. The northern part of the west coast plains is known as the Konkan Coast and the southern part as the Malabar Coast. The western coast has a number of big seaports, such as Mumbai and Cochin. The eastern coastal plains are wider than the western plains and the alluvial deposits are thicker. A number of rivers, such as the Mahanadi, the Godavari, the Krishna, and the Cauvery, have the deltas on the eastern coast.

The Islands

The Andaman and Nicobar islands consist of a total of 572 picturesque islands in the South Eastern part of the Bay of Bengal. They lie along an arc in long and narrow broken chain, approximately North-South over a distance of nearly 800 km. Most of these islands are of small size, less than 50 km in length. The other group of islands known as the Lakshadweep group is in the Arabian Sea. This tiniest Union Territory of India with an area of 32 sq. km is an archipelago mainly consisting of ten inhabited islands and 17 uninhabited islands. The inhabited islands are Kavaratti, Agatti, Amini, Kadmat, Kiltan, Chetlat, Bitra, Andrott, Kalpeni and Minicoy. The islands are located in the Arabian Sea between 8° to 12°13’ North latitude and 71° to 74° East longitude, 220 to 440 km away from the coastal city of Kochi in Kerala.