Assessment of Dam-Induced Changes in Ecogeomorphological Behaviour and Fluvial Functionality in the Damodar River, West Bengal, India

Abstract Anthropogenic interventions in the form of dams and barrages often alter the fluvial functionality and ecogeomorphological (geomorphology, hydrology, and ecology) behaviour of the river systems. The present work examines the environmental flow, channel metamorphosis, and fluvial functionality of Damodar River in the context of Damodar Valley Corporation (DVC) dams and development. The structural (dams, barrages, weirs, etc.) and non-structural (urban-industrial and agricultural disposal with effluents, sand mining, etc.) interventions hinder the ecological functionality of the river. This study portrays that the eco-geomorphological behaviour and fluvial functionality of the river have changed due to flow alteration and diversion by dams and barrages and due to the urban-industrial and agricultural growth in the basin area. These changes have affected riverine ecological integrity. The ecological functionality level of this study area ranges from 85 to 181 i.e. poor to good-fair. The ecological functionality level in sample channel sections (i.e., immediate upstream and downstream of Durgapur Barrage) is poor, and the value ranges from 61 to 100 due to the hydrological impact of the barrage and the Durgapur urban-industrial belt. This assessment work would help to restore the fluvial environment for humans as well as riverine biota.