ENVIRONMENTAL FLOW ASSESSMENT FOR ECOSYSTEM HEALTH IN A REACH OF BAITARANI RIVER

Abstract

Rivers have always been vital to mankind as well as for other living beings infact, most civilizations started from the bank of Rivers. Since Rivers have been a source of food and home for variety of aquatic plants and animals and sustains an ecosystem, the alteration of the water flow is one of the most stressful factors influencing the aquatic and riverine ecosystem. Salubrious ecosystems help preserving the food, maintain the cycle of symbiotic relationship and keeps water quality healthy, therefore the condition of aquatic ecosystem is a measure for environment which depends on the flow in the stream. This essential flow is termed as Environmental Flow. Rivers need Environmental Flow to maintain the ecology of the systems and also sometimes rivers have to face water related challenges including increasing issue of the water scarcity and distribution for water among different sectors and states are being faced presently at global level. The present study aims to estimate the Environmental Flow of Baitarani River upto Anandapur, Odisha from its origin and analysis of eco-hydro relationships in time by environmental flow assessment. WMS, HMS, DSSvue and EFM software were used for assessing the Environmental Flow employing the DEM (Digital Elevation Model), precipitation, soil, Land use land cover (LULC), discharge, gauge and ecosystem data for the aquatic species in the present study. The environmental indicators employed for the research are Small Fishes, Maggar, Benthic Macro-Invertebrate Biodiversity, Wetland, Catla-Catla, Rohu, Hilsa and their corresponding assessed E-flow are 148, 6, 7, 122, 267, 254 and 272 cumecs respectively for observed flow of 17 years viz. 2000 to 2016. Through confiscate such as dams, barrages and weirs which are constructed for irrigation, drinking water, hydro-project and for other industrial demand. This does not only make restriction on the flow of water but also degrade the water quality. An attempt has also been made to estimate the E-flow which could only be provided upto certain values in case of climate change and future development flow regime for the above mentioned species and their corresponding values are 129, 5, 6, 106, 232, 221, 236 and 52, 2, 3, 43, 93, 89, 95 cumecs respectively.