Physiographically, India may be divided into seven well defined regions. These are:
1.The Northern Mountains, comprising the mighty Himalayan ranges;
2.The Great Plains, traversed by the Indus and Ganga Brahmaputra river systems. As much as one third of this lies in the arid zone of western Rajasthan. The remaining area is mostly fertile plains;
3.The Central Highlands, consisting of a wide belt of hills running east-west starting from Aravalli ranges in the west and terminating in a steep escarpment in the east. The area lies between the Great Plains and the Deccan Plateau;
4.The Peninsular Plateaus comprising the Western Ghats, Eastern Ghats, North Deccan Plateau, South Deccan Plateau and Eastern Plateau;
5.The East Coast, a belt of land of about 100-130 km wide, bordering the Bay of Bengal land lying to the east of the Eastern Ghats;
6.The West Coast, a narrow belt of land of about 10-25 km wide, nordering the Arabian Sea and lying to the west of the Western Ghats, and;
7.The islands, comprising the coral islands of Lakshadeep in Arabian Sea and Andaman and Nicobar Islands of the Bay of Bengal.