The Bengal Delta

Where it is

The Bengal delta is the largest river delta on Earth, built by the Ganges and Brahmaputra where they meet and spread across Bangladesh and West Bengal before reaching the Bay of Bengal. It is enormous, extremely flat, and very densely populated — tens of millions of people living a couple of metres above sea level on ground the rivers are still making. At its seaward edge is the Sundarbans, the largest mangrove forest in the world, straddling the India–Bangladesh border.

The land and water around it

• The Sundarbansforest

  Mangrove forest at the delta's seaward margin, split by the border. It absorbs storm surge before it reaches inhabited land, and it depends on a particular balance of fresh and salt water that upstream diversion changes.

• The Hooghlyriver

  A western distributary, and the channel the East India Company used. It has been silting for centuries; a barrage at Farakka diverts Ganges flow into it to keep it navigable.

• The Meghna estuarydelta

  The delta's main outlet today, carrying the combined Ganges and Brahmaputra. Its position reflects the eastward migration of the main flow.

Its history, in short

The delta's channels have never held still: the main flow has shifted east across the delta over the past few centuries, abandoning some cities and creating others. Bengal was among the wealthiest regions of the Mughal Empire, exporting textiles at a scale that made its name a byword for cloth, and was the first part of India brought under East India Company rule after 1757. Its modern history is defined by two divisions — the partition of 1947 and the war of 1971 — and by an ongoing negotiation with water that is now complicated by upstream barrages, cyclones and sea-level rise.

Timeline

Dates are shown on a timeline rather than as changing shapes on the map. The globe draws modern boundaries only, and tinting a modern outline to stand for a historical one would state something we cannot source.

Places that carry meaning

• Kolkata1690s onward

  Founded on the Hooghly because the channel was then navigable far inland for ocean-going ships. The channel silted, the port's activity moved downstream, and the city stayed.

• The SundarbansPresent day

  Inscribed as World Heritage on both sides of the border under separate listings. Home to a tiger population, and to people who enter the forest for honey and fish and sometimes do not return.

Learn the language here

1. 1Understand which languages are spoken hereThe Bengal Delta is multilingual. Start with which languages are used, by whom, and for what — the phrase list only covers one of them.Written by Globe Quest

Check yourself

• What has the delta's main channel done over recent centuries?

  Migrated progressively eastward, stranding some ports and creating others

  Delta channels are not fixed addresses, which is why Kolkata's founding advantage expired.

• What was the Bengali Language Movement about?

  Opposing the imposition of Urdu as Pakistan's sole national language

  The 1952 protests and killings are commemorated internationally, and the movement fed directly into Bangladeshi independence.

Worth arguing about

• A single language region divided by a border, negotiating over a river that ignores it. What should govern a shared delta?
• Bangladesh exists partly because of a language dispute. Where else has language been the fault line rather than the symptom?

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