<P> In 1809, Buchanan Hamilton wrote that the new channel between Bhawanipur and Dewanranj "was scarcely inferior to the mighty river, and threatens to sweep away the intermediate country". By 1830, the old channel had been reduced to its present insignificance . It was navigable by country boats throughout the year and by launches only during rains, but at the point as low as Jamalpur it was formidable throughout the cold weather . Similar was the position for two or three months just below Mymensingh also . </P> <P> The Brahmaputra River experiences high levels of bank erosion (usually via slab failure) and channel migration caused by its strong current, lack of river bank vegetation, and loose sand and silt which compose its banks . It is thus difficult to build permanent structures on the river, and protective structures designed to limit the river's erosional effects often face numerous issues during and after construction . In fact, a 2004 report by the Bangladesh Disaster and Emergency Sub-Group (BDER) has stated that several of such protective systems have' just failed' . However, some progress has been made in the form of construction works which stabilize sections of the river, albeit the need for heavy maintenance . The Bangabandhu Bridge, the only bridge to span the river's major distributary, the Jamuna, was thus opened in June 1998 . Constructed at a narrow braid belt of the river, it is 4.8 km long with a platform 18.5 m wide, and it is used to carry railroad traffic as well as gas, power and telecommunication lines . Due to the variable nature of the river, prediction of the river's future course is crucial in planning upstream engineering to prevent flooding on the bridge . </P> <P> China had built the Zangmu Dam in the upper course of the Brahmaputra River in the Tibet region and it was operationalised on 13 October 2015 . The main purpose of the dam was to generate electricity for China and its operation has caused concerns for downstream neighbours like India as the presence of dams in the upper course of the river will mean unpredictability in the dynamics of downstream flows . </P>

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