Assessing land erosion and accretion dynamics and river bank line shifting of upper reach of Hooghly river of West Bengal, India

River bank line shifting and channel migration due to river bank erosion and accretion causes inevitable geomorphic hazards in Gangetic West Bengal, India. Channel oscillation and associated river bank erosion-accretion is the widespread hydro-geomorphic phenomenon of the Bhagirathi-Hooghly river. In the present analysis, an attempt has been made to investigate the pattern of bank line shifting and river bank erosion-accretion dynamics of the 85 km long upper reach of the Hooghly river for the last 100 years with the use of geospatial techniques. The study is based on police station maps (1917–1921), topographical sheets (1954) and Landsat imageries of 1972, 1990, 2005 and 2020, which were collected from different sources. Sinuosity index, radius-wavelength ratio and bend-tightness index of different time periods have been computed for analyzing the temporal changes that occurred in the study reach. The result shows that the sinuosity index decreased from 1.95 in 1921 to 1.87 in 2020 and the areal extension of bank erosion and accretion decreases. This study has also developed a model for future prediction of river centerlines in the coming decades to identify future hazard zones. The overall channel migration of the upper reach of the Hooghly river indicates the oscillatory nature of the river channel. Channel widening, meander bend development and lateral movement of the channel are responsible for erosion and accretion of the bank. Therefore, the present analysis may be helpful for the identification and mapping of future vulnerable areas and make a plan for the lives of the people living near the bank line for their safety and sustainability.