India Natural Environment

India has an area of nearly 3 million sq km, which can be divided into three main geographical regions.

The Himalayas form India’s northern borders with China, Nepal and Bhutan.   Movements of the earth’s crust pushing the Indian subcontinent plate against the Asian plate created these mountains.  These movements are still occurring, causing periodic earthquakes.  The Himalayan system is made up of three parallel ranges, the Greater Himalayas, the Lesser Himalayas, and the Outer Himalayas

The Greater Himalayas averages about 6,000 meters in height and contains the three highest mountains on earth: Mount Everest (8,796 m) on the China-Nepal border; K2 (8,611 m) in an area claimed by India, Pakistan, and China; and Kanchenjunga (8,598 meters) on the India-Nepal border.  The Karakoram Range in the west is where India, Pakistan and China meet.  The Lesser Himalayas, in the states (from west to east) of Himachal Pradesh, Uttar Pradesh, Sikkim and Arunachal Pradesh, ranges from 1,500 to 5,000 m in height.  The well-known hill station Darjeeling is in this region.  The Outer Himalayas, averaging 900 to 1,200 m above sea level, is the southern-most range.

Between the ranges are plateaus, gorges, and valleys, including Kashmir and Kulu.   North-eastern India adjacent to Burma and Bangladesh consists of hills averaging between 1,000 and 2,000 m in elevation, but are not associated with the Himalayas.

The next region is the Indo-Gangetic Plain.  The Ganges river is about 2,500 km long and the basin is from 320 to 640 km wide.  The plain makes up more than 25 percent of India’s land area and extends from the Indus River basin to the Haryana Plains and finally to the Ganga delta in Bangladesh.  The Ganges originates from the glaciers of the Greater Himalayas; before it flows into the Bay of Bengal, it is joined by the mighty Brahmaputra River flowing south from Bangladesh. 

The third region is the triangle-shaped peninsula, which starts in the north from the escarpments of the Vindhya Range.  The peninsula has an elevation ranging from about 300 m to 1,800 m.  The central part of the peninsula slopes down eastwards.  Therefore, many rivers, such as the Krishna and the Kaveri flow eastwards into the Bay of Bengal.  The regions between the peninsula and the seas are coastal plains, estuaries, marshes and river deltas.

Apart from the three main regions are two main island groups: the Andaman and Nicolar Islands in the Bay of Bengal about 1,000 km off the peninsula, which have over 200 islands extending more than 1,000 km from north to south.  In the Arabian Sea are the Lakshadweep islands which are mainly of coral origin spread over 77,000 sq km.  The total land area of the islands is less than one percent of the entire country.

Generally apart from the Himalayan region, most of India is hot; but the southwest monsoon (from June to September) brings heavy rains and high humidity, and lower temperature.  As a generalisation, in the summer months (March to May), the temperature can be up to 48°C.   Most rain falls during the southwest monsoon season (June to September) in all regions and the weather tends to become cooler.  October to November is the northeast monsoon season, with less rain falling.  Winter is from December to February and is dryer and cooler.

Despite the above generalisation, India has several climatic zones caused by their geographical locations and altitude, and the temperatures and precipitations in each location can vary from year to year.

In the Himalayas, the temperatures become cooler in higher altitudes.  For land above 4,500 m, the temperature tends to be below freezing.  However, in the lower-lying valleys and basins, the summer temperature can be in the low 30s Celsius.

In the Indian northeast region of Assam and West Bengal, the climate is wet and humid and hot in the south near the Bay of Bengal, but is much cooler in the Himalayan portion of the states, such as at the Darjeeling Hill Station.

For the Ganges basin, the temperatures and precipitations vary from the west to the east.  Average annual rainfall increases as one moves from the west (about 60 cm) to the east (about 150 cm).  During the spring, parts of the Ganges basin especially around Delhi tend to be foggy.

In the Peninsula, the Western Ghats region (off the Arabian Sea) receives much heavier rain than the Eastern Ghats (off the Bay of Bengal).

The southwest monsoon, which comes from the Arabian Sea from June to September, accounts for most of the India’s rainfall.  The northeast monsoon comes in November and December with wind from the northeast bringing rain to the states of Tamil Nadu, Karnataka, and Kerala.