Remote Sensing and GIS–Based Analysis of Channel Pattern Morphology Using a Scientific Approach

River channel morphology varies from single-thread straight channels to complex multi-thread networks. The Bhagirathi–Hooghly River Basin exhibits pronounced planform variability, with significant meandering particularly along its middle course. This study employs remote sensing and Geographic Information System (GIS) techniques to analyse river planform characteristics and channel pattern morphology. Landsat-8 satellite imagery, OpenStreetMap (OSM) base maps, and SWORD shapefiles were integrated using the WGS-84 projection system for spatial analysis. The Bhagirathi–Hooghly River extends approximately 486.52 km from the Murshidabad district to the Bay of Bengal, and its course is divided into eight reaches for detailed assessment. The study evaluates river channel network characteristics using multiple geomorphological indices, including the Braiding Index (Germanoski and Schumm, 1993), Sinuosity Index (Friend and Sinha, 1993), Width Ratio (Hong and Davies, 1979), and the Normalised Difference Water Index (NDWI) to assess river health. The results indicate a Braiding Index value of 0.821, a Sinuosity Index of 1.50, and a Width Ratio of 1.26 for the Bhagirathi–Hooghly River Basin. NDWI values range from − 0.382 to 0.181 in the middle reaches and from − 0.335 to 0.189 in the lower reaches. These findings demonstrate that the river system is predominantly meandering rather than braided. Additionally, bar and island areas are more extensive in the lower floodplain, while the middle reaches contain numerous but relatively smaller bars and islands. The study highlights the effectiveness of integrated remote sensing and GIS approaches in quantitatively assessing river morphology and health.