The
Ganges basin is a part of the
Ganges-
Brahmaputra-
Meghna basin draining 1,086,000 square kilometres in
Tibet,
Nepal,
India and
Bangladesh. To the north, the
Himalaya or lower parallel ranges beyond form the Ganges-Brahmaputra divide. On the west the Ganges Basin borders the
Indus basin and then the
Aravalli ridge. Southern limits are the
Vindhyas and
Chota Nagpur Plateau. On the east the Ganges merges with the Brahmaputra through a complex system of common distributaries into the
Bay of Bengal. Its catchment lies in the states of
Uttar Pradesh (294,364 km²),
Madhya Pradesh (198,962 km²),
Bihar (143,961 km²),
Rajasthan (112,490 km²),
West Bengal (71,485 km²),
Haryana (34,341 km²),
Himachal Pradesh (317 km²) and
Delhi (1,484 km²), the whole of Bangladesh,
Nepal and
Bhutan. Several tributaries rise inside
Tibet before flowing south through Nepal. The basin has a population of more than 500 million, making it the most populated river basin in the world.