A GEOSPATIAL ANALYSIS ON RIVER DYNAMICS IN UPPER ACTIVE BRAHMAPUTRA-JAMUNA FLOODPLAIN REGION, BANGLADESH

The hydro-geomorphic dynamism of the Brahmaputra-Jamuna River system in Bangladesh poses critical challenges for sustainable river management, given the country's vulnerability to climate change and riverbank erosion. The present study employs a longitudinal analysis of Landsat and Sentinel images from 1988 to 2023, integrated with Remote Sensing (RS) and Geographic Information Systems (GIS), to provide a temporal assessment of the river’s dynamic behavior. Results reveal significant temporal and seasonal fluctuations in the riverbed's spatial extent, dynamism rate, and common area, underlining the system's inherent volatility. Between 1988 and 2023, the riverbed’s area exhibited marked variability, ranging from 237.9537 km² to 365.8552 km². Seasonal evaluations also pinpointed pronounced changes, particularly in pre-monsoon and monsoon periods, revealing substantial variations in dynamism area and rates. The study uncovers intriguing patterns, such as the anomalous high dynamism area in 2020 and the surge in winter dynamism rate in 2022, calling for a deeper inquiry into potential climatic anomalies or anthropogenic influences and the need for ongoing monitoring and adaptive river management, particularly under increased environmental stress from climate change.