Environmental sustainability of major rivers of Jharkhand, India

Abstract

Environmental flows (EFs) are the minimum quantity and quality of flows required to sustain freshwater ecosystems and human livelihoods. Achieving environmental sustainability in rivers involves managing EFs while balancing ecological, economic, and social goals and ensuring fair access to resources. In this study, EFs for four major rivers in Jharkhand - the North Koel, Sone, Damodar, and Mayurakshi - were determined using the Global Environmental Flow Calculator. The study used monthly flow data and Flow Duration Curve to estimate EFs to improve the condition of the rivers' ecosystems, known as Environmental Management Class (EMC). Results showed that EFs for the Jharkhand rivers ranged from 6% to 16.6% of the Mean Annual Runoff (MAR). For example, the North Koel River (Daltonganj) and other rivers in that region had EFs ranging from 6% to 12.6% of MAR, while the Kanhar River had EFs of 11.6% of MAR. The Damodar and related rivers had EFs ranging from 9% to 16.6% of MAR, and the Mayurakshi, Bansloi, and Basane rivers had EFs around 10% of MAR. Additionally, the study found that the Sankh river had a sustainability index of 12.0, indicating a very sustainable flow regime. The study highlighted that changes in flow characteristics could pose a significant threat to fish diversity and community structure, raising concerns about the future of these ecosystems. It emphasized the importance of managing water storage structures to maintain environmental flow, species diversity, flow fluctuation, and river pollution.