Analysis of channel shifting and its impact on morphometric parameters of Sone river basin, Bihar, India

Controlling the natural force of rivers and predicting associated natural disasters pose significant challenges. However, conducting comprehensive monitoring of river course variations and morphological changes is crucial for implementing effective management plans and mitigation measures for rivers. This study aims to investigate changes in the course of the Sone river and its implications on the morphometric features of the surrounding basin. Using DEM data and Landsat satellite imagery from 2005 to 2020 at 5-year intervals, the Digital Shoreline Analysis System (DSAS) tool was employed to analyze river migration and parameters Net River Migration (NRM), End Point Rate (EPR), and Linear Regression Rate (LRR) were computed. The statistical result of the study revealed a westward shift in the river channel with the maximum NRM erosion value of –5174.52 m along with an EPR of –956.04 m/year and LRR of –451.87 m/year. Erosion and accretion areas were identified using ArcGIS, showing significant erosion trends from 2010 to 2020. The morphometric analysis encompassed the quantification of variables associated with linear, areal, and relief aspects. A low bifurcation ratio of 1.90 indicates limited structural control, heightening the risk of flooding. The elongated shape of the basin, combined with low drainage density and increased overland flow length leads to prolonged concentration periods. Additionally, the hypsometric curve portrays the river basin as an old and eroded basin. Overall, this study underscores the potential of the DSAS tool in assessing channel migration and its impact on basin morphometry, offering insights into potential water availability issues throughout the basin.