Abstract River channel morphology plays a critical role in riverine ecosystems, society and the entire basin. However, quantifying river channel morphological changes and identifying sediment deposition hotspots are poorly understood in mountain river systems. This study utilized multi‐temporal satellite images to assess the river channel morphological dynamics and sedimentation over the past 30 years (1990–2020) in Tamor River of the Central Himalaya, Nepal. Geospatial and statistical techniques were employed for a detailed analysis of the 10 divided river reaches for six subperiods. Over 30 years, the midstream section experienced significant changes in channel width, area and mid‐channel bar, whereas both upstream and downstream sections displayed minimal morphological variation. Across all river sections, the erosion area (12.75%) slightly exceeded the deposition area (11.33%). The river centerline and thalweg exhibited a consistent pattern of asymmetric migration, dominated by a maximum rightward centerline migration of 301.47 m, compared to 250.59 m leftward in the middle reaches. Results showed that the notable sediment deposition hotspots concentrated along the right bank of the sinuous bends of the downstream reaches. The most pronounced channel instability occurred from 1995 to 2005, driven by intense precipitation and extreme flood events. These findings provide a strong foundation for infrastructure planning and engineering measures to mitigate river disasters, especially in Himalayan River systems.
Shrestha et al. (Sun,) studied this question.