DYNAMIC RIVER CHANNEL MIGRATION IN THE GANGES-BRAHMAPUTRA-MEGHNA DELTA, BENGAL BASIN

Most of Bangladesh comprises the Ganges-Brahmaputra-Meghna Delta, the world's largest delta, and houses some of the longest rivers in the world. This study examines the river channel migration in Bangladesh, specifically focusing on the Ganges, Brahmaputra (Jamuna), Padma, and Meghna Rivers. By analyzing Sentinel-2 satellite imagery and utilizing ArcGIS Pro software, this research investigates channel stability for the past 32 years, comparing the 2022 river paths from those of 1990. The study reveals intriguing dynamics of the entire fluvial system. The Brahmaputra/Jamuna River maintains its overall flow path, likely controlled by the Jamuna Fault. While the river keeps its braided configuration, it undergoes noticeable changes in individual channel-flow paths. On the other hand, the Ganges-Padma River system has experienced large changes in the flow pattern, attributed to factors like the Farakka Barrage and reduced water discharge. Older multi-thread channels are evolving more into single-thread ones. The upper Meghna River maintains its anastomosed pattern, with remarkable stability of its individual flow paths. Whereas the wider, lower Meghna River shows more susceptibility to erosion due to the convergence of multiple channels and rising sea levels.

Our study provides valuable insights into the dynamics of river networks in Bangladesh, emphasizing the importance of considering geological activity, human interventions, and climatic changes in understanding and managing the river systems in the region. These river systems affect the livelihood of roughly 170 million people, particularly regarding landscape alteration, environmental displacement, and economic growth.