Riverbank erosion and accretion (RBEA) are critical geomorphological processes shaping riverine landscapes and socio-economic vulnerability in Bangladesh. However, existing studies on the Karnaphuli River examine morphological change or environmental conditions in isolation, with limited integration of long-term river dynamics and community-level adaptation. This study addresses this gap by combining multi-temporal geospatial analysis with household-level socio-economic investigation to assess RBEA dynamics and adaptation strategies along a 76 km river stretch of the Karnaphuli River from 1993 to 2023. The results reveal pronounced spatial asymmetry in erosion–accretion patterns. Right bank erosion increased from 0.34 km² (1993–2003) to 1.65 km² (2013–2023), while accretion declined sharply from 2.58 km² to 0.21 km². In contrast, the left bank showed lower long-term erosion (0.58 km²) and higher accretion (1.87 km²), indicating relative stabilization. Erosion rates reached up to 166 m/year on the right bank, highlighting increasing vulnerability. These geomorphological changes are associated with significant socio-economic impacts, including widespread land loss, displacement, and a shift from agriculture and fishing to informal livelihoods. Households primarily relied on short-term coping strategies such as borrowing and reduced consumption, reflecting limited adaptive capacity. Statistical analysis indicates weak associations between selected socio-economic variables and erosion impacts, suggesting that vulnerability is shaped by multiple interacting factors beyond those captured in the models. While the study provides valuable insights, it is constrained by the use of medium-resolution satellite data and the absence of direct hydrodynamic measurements. The findings underscore the need for location-specific riverbank management, improved sediment governance, and targeted livelihood support, contributing to evidence-based planning for climate-resilient riverine communities. Not applicable.
Chowdhury et al. (Mon,) studied this question.