Spatio-Temporal Analysis of Channel Morphometry and Morphological Dynamics of the Lower Subarnarekha River Basin, Odisha, India: A Geo-informatics Approach

The morphological evolution of river channels is a continuous process driven by hydrodynamic fluctuations and human interventions. This study evaluates the spatio-temporal changes in the channel geometry of the lower Subarnarekha River basin in Balasore, Odisha, over several decades. Utilizing multi-temporal Landsat imagery (MSS/TM 4-5 and OLI 8)integrated with ArcGIS and Google Earth Pro, the research quantifies shifts in river course and estuary dynamics.Statistical validations were performed using Origin-Pro 2022 and MS EXCEL. Findings reveal significant morphologicalinstability, particularly between 2015 and 2020, characterized by an increase in the Sinuosity Index within specific grids(A5) and river points (5-6). A notable reduction in water volume has been observed since 2014, while sand dunes andsand banks have shown a declining trend since 2004, likely due to intensive sand mining and monsoonal dischargevariations. Interestingly, the Braided Index showed a gradual decrease from 1985 until a rapid resurgence in 2005.Furthermore, localized analysis of the Subarnarekha estuary (Grid A7) indicates a steady increase in sand bar formationsince 2005. These results underscore the highly dynamic nature of the Subarnarekha riverbed, providing a criticalbaseline for flood management and sustainable river-resource regulation.