Assessment of spatiotemporal erosion and accretion patterns in the Jamuna riverbanks using satellite and morphological data

Riverbank erosion is a significant and recurring hydro-morphological hazard in Bangladesh, particularly along the Jamuna River, one of the most dynamic braided rivers in South Asia. This study aims to assess the spatiotemporal dynamics of riverbank erosion and accretion patterns and evaluate their impact on navigability in the Dewanganj and Islampur upazilas of Jamalpur district. Utilizing 30 years of Landsat satellite imagery (1995–2024), including geospatial tools such as Google Earth Engine and ArcGIS, and morphological data, the study analyzes the extension of lateral and vertical erosion and accretion, bank-line shifts, and river morphology changes. In the results, it is found that lateral migration of the river is very extensive, and during the study period (1995–2024), about 55,436 hectares of land have been eroded, and 53,496 hectares have been accreted, indicating persistent lateral instability. Despite this balance, both satellite imagery and cross-sectional analysis indicate a relative dominance of accretion in recent years, contributing to rising sedimentation and declining river depth, and resulting in a narrowing of navigation routes. Field observations corroborate satellite-derived findings and highlight socioeconomic consequences, such as rising transportation costs (40–60%), longer trip times (60–70%), and greater dredging demands, particularly during the dry season. The study evaluates river dynamics and navigability constraints, showing how well satellite remote sensing, morphological analysis, and field surveys may be integrated. The method used provides a strong framework for river management and navigation planning in sediment-rich alluvial systems and can be extended to other braided rivers in Bangladesh, including the Teesta, Dharla, and Lower Padma.