Doab

Doab دوآب / दोआब
Natural region
View of a canal in the lower Bari Doab of the Punjab Doabs
Country	Pakistan and India

Doab (Urdu: دوآب, Hindi: दोआब, from Persian: دوآب dōāb, from dō, "two" + āb, "water" or "river") is a term used in India and Pakistan for the "tongue," or tract of land lying between two converging, or confluent, rivers. It is similar to an interfluve. In the Oxford Hindi-English Dictionary, R. S. McGregor defines it as "a region lying between and reaching to the confluence of two rivers (esp. that between the Ganges and Jumna)."

Since North India and Pakistan are coursed by a multiplicity of Himalayan rivers that divide the plains into doabs (i.e. regions between two rivers), the Indo-Gangetic plains consist of alternating regions of river, khadir and bangar. The centres of the doabs consist of low-lying flood-prone bangar and the higher-lying peripheries which line the rivers, consist of khadir.

Historically, villages in the doabs have been officially classified as khadir, khadir-bangar (i.e. mixed) or bangar for many centuries and different agricultural tax rates applied based on a tiered land-productivity scale.

The United Provinces Doab, covers the current Uttar Pradesh and Uttarakhand states is unqualified by the names of any rivers, designates the flat alluvial tract between the Ganges and Yamuna rivers extending from the Sivalik Hills to the two rivers' confluence at Allahabad. The region has an area of about 23,360 square miles (60,500 square km); it is approximately 500 miles (805 km) in length and 60 miles (97 km) in width.