GangesBrahmaputraMeghna

The Ganges-Brahmaputra-Meghna (GBM) is a major river system in South Asia, spanning parts of India and Bangladesh. It comprises three large rivers—the Ganges, the Brahmaputra, and the Meghna—and their extensive networks. Together they form one of the world’s largest and most fertile deltas, supporting vast floodplains and the Sundarbans mangrove forest along the Bay of Bengal.

Origin and course: The Ganges rises in the Himalayas and flows east across northern India before entering Bangladesh as the Padma. The Brahmaputra originates in the Tibetan Plateau, traverses Tibet and India, and in Bangladesh is known as the Jamuna. Downstream these rivers contribute to a complex system that is fed by numerous tributaries and distributaries before discharging into the Bay of Bengal.

Hydrology and delta: The GBM delta is shaped by seasonal monsoon floods and a very large sediment load, creating broad distributaries and mudflats. The lower river reaches include the Meghna, which drains the delta into the sea, and the Sundarbans, a UNESCO World Heritage site.

Human use and ecology: The GBM basin supports agriculture (rice, jute), fisheries, and riverine transport. Dhaka and other urban centers rely on these rivers. The Sundarbans and associated ecosystems host diverse flora and fauna, including the Bengal tiger. The region is prone to cyclones, floods, and gradual sea-level rise.

Management and challenges: Water sharing and flood management are matters of bilateral diplomacy between India and Bangladesh. Major works such as the Farakka Barrage on the Ganges and various flood-control projects influence flows. Ongoing climate change threatens sediment balance, navigation, ecosystems, and coastal livelihoods.