Land is an invaluable asset which supports natural vegetation, wildlife, human life, economic activities, and transport and communication systems. About 43 per cent of land area in India is occupied by plains which provide for agriculture and industries. About 30 per cent of land area is mountainous. These mountains are sources of perennial rivers and also provide for tourism. About 27 per cent of land area in India is under plateaus, which are rich reserves of minerals, fossil fuels and forests.