Channel instability and hydrogeomorphic adjustment in alluvial reach of Kangsabati River, India using Digital Shoreline Analysis System and Acoustic Doppler Current Profiler

Abstract

Despite the stable stratigraphic setup in plateau basin, several anthropogenic interventions triggered geomorphic sensitivity by hydrodynamic metamorphosis. Present research focussed to evaluate the hydrogeomorphic evolution for anthropogenic interventions in Kangsabati River as measured by channel migration rate (CMR), bankline shifting, and erosion-accretion of last thirty years (1990–2020) in 454 mouza using Digital shoreline analysis system (DSAS). Acoustic Doppler Current Profiler (ADCP) was used to directly estimate bank scouring or erosion measuring of hydraulic variables during bankfull discharge across the DSAS transects. DSAS denoted that decaying CMR (64–46 km) decreased accretion area (4.08–1.44 km²) but increased erosion area (2.12–2.44 km²). ADCP revealed that sand mining induced super-critical flow, bridge and embankment generated maximum boundary shear, and mining bed slope increased hydraulic action for channel widening and bank erosion especially middle and lower segments. This study has provided information about channel instability, and bank erosion hazard planning and management.

Keywords:

• Geomorphic sensitivity
• hydrogeomorphic evolution
• bank scouring
• bankfull discharge
• super-critical flow

Acknowledgements

Authors are thankful to the Department of Science and Technology India for providing a Acoustic Doppler Current Profiler to Dept. of Geography, Vidyasagar University. We are also grateful to Irrigation Office of Paschim Medinipur, District Land & Land Reforms officer of the Paschim Midnapore districts, WB in India, for providing the discharge, sand mining data of the Kangsabati River. Finally, critical reviews by three anonymous referees and editor guidance helped to highly improve the revised manuscript. Authors are also immense grateful to Dr. Prasenjit Acharya, Vidyasagar University, for his valuable suggestion and correction in revised version of manuscript.

Disclosure Statement

No potential conflict of interest was reported by the author(s).