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The current study explores the planform morphological changes that have occurred in the upper segment of the Yamuna River by using Landsat images from 1979 to 2019. The river segment was divided into 18 sections at equal spacing, viz., S1 to S18, and the centerline and bank line shifting, channel width, alterations in meander geometry and braiding characteristics in terms of sinuosity index (SI) and braiding index (BI) were evaluated. The results indicate a maximum centerline shifting eastward at section S-5 and westward at S17 during 1999, with respect to the base year of 1979. The average eastward and westward centerline shifting remained insignificant. The average west bank shifting ranged from 0.407 km to 0.892 km east and 0.440 km to 0.418 km west, indicating relatively higher west bank shifting towards east. The average east bank shifting ranged from 0.335 km to 0.505 km east and 0.344 km to 0.896 km west, indicating a narrowing of the bank width throughout the segment length. During the assessment period, the river segment exhibited sinuous characteristics and non-braided behavior. The outcomes of this study could be useful in predicting future trends in river shifting and developing sustainable land use planning strategies along floodplains. [ABSTRACT FROM AUTHOR]

Lateral migration of the Bhagirathi River temporally creates unavoidable geomorphic hazards in West Bengal, India. The Bhagirathi River flows SW for ~67.30 km between the confluence point of Ajay and Jalangi rivers in East Burdwan and Nadia districts of West Bengal. The course of Bhagirathi is notably migration prone and cultivates problematic changes along its course over time. In the study, we have looked into its migration tendency and unpredictability for past 238 years and then predicted the lateral shifting of river centerline using temporal satellite imageries — Landsat-5 (TM) of 1987 (8, December), 1995 (28, January), 2005 (7, January) and LISS-IV satellite imagery (2017, 5 January);SOI Toposheet — 1968-1969 (79A/2, 79A/3, 79A/6 and 79A/7) and Rennell's map of 1779. Other highlights are the quest of fluvial features, oxbow lakes, mid-channel bars, channel migration rate, meander geometry, channel sinuosity in different parts of river course and the parts that experience intensive bank erosion. The entire river course has been subdivided into three segments; viz. reaches A, B and C. Investigation displays that degree of sinuosity decreases from its anterior course (1968) to the existing course (2017). Reach-specific outputs display that reach B is highly sinuous (SI value 1.94 in 2017) and SI increases temporarily, whereas for reaches A and C it decreases with time. The rate of migration is higher in reach B than that in reaches C and A. The study displays a notably decreasing trend of migration in comparison with its previous lateral migration and shows that the migration nature over time is intensively inconsistent and unpredictable except very few portions of the river course. The nature of deposition within the river channel shows an unstable behavior during the entire period of the study. Meander geometry depicts a rapid change of river course innate to meander bends and shows a higher rate of migration by meander loop cut-off rather than lateral migration that reflects the inconsistency, erosion vulnerability and unpredictable nature of migration. The present work offers a valuable source to comprehend channel changes in Bhagirathi River and serve as an efficacious base for river-bank migration and erosion hazard planning and management. [ABSTRACT FROM AUTHOR]