Multi-decadal land use and land cover changes driven by the braided river Brahmaputra and its socio-economic implications in Assam, India

The Brahmaputra River (BR) is one of the world’s most dynamic rivers, and its channel migration significantly impacts the land use and land cover (LULC), and socio-economic stability of Assam, India. This study evaluates LULC changes within the river corridor and their impact on socio-economy of the region. Multi-temporal satellite imagery from 1976 to 2020 was analysed using hybrid classification techniques and manual recoding to map seven LULC classes. River dynamics was quantified through bankline shift and overlay analysis. Results indicate a pronounced south-westward shift of the river, with average bankline shifts of 1.71 km on the left bank and 1.74 km on the right bank. Over 44-years, 1552.2 km2 of land was lost to erosion, while 286.5 km2 was formed through deposition. Erosion severely affected agriculture (705.9 km2), threatening food security and livelihoods, and vegetation (446.3 km2), reducing ecological resources. Critically, Built-up losses (78.7 km2) exposed settlements to displacement and infrastructure damage, representing the most immediate socio-economic impact. Conversely, deposition resulted in constructive change supporting agriculture expansion (131.1 km2), vegetation growth (63.6 km2), and settlement development (17.1 km2). These findings underscore that agriculture, vegetation and settlements, the core socio-economic pillars of Assam’s floodplain communities are directly shaped by river dynamics.