A Comparative Study on Environmental Flows Assessment Methods in Lower Reach of Mahanadi River

  IJETT-book-cover  International Journal of Engineering Trends and Technology (IJETT)          
© 2016 by IJETT Journal
Volume-32 Number-2
Year of Publication : 2016
Authors : Sangitarani Sahoo, Deepak Khare, Prabhas K Mishra, Satyapriya Behera, Radha Krishan
DOI :  10.14445/22315381/IJETT-V32P215


Sangitarani Sahoo, Deepak Khare, Prabhas K Mishra, Satyapriya Behera, Radha Krishan"A Comparative Study on Environmental Flows Assessment Methods in Lower Reach of Mahanadi River", International Journal of Engineering Trends and Technology (IJETT), V32(2),82-90 February 2016. ISSN:2231-5381. www.ijettjournal.org. published by seventh sense research group

Environmental flows assessment is a process which determines the allocated water for maintaining aquatic habitats and ecological processes in a environment. The river system attains zero flow in low flow period due to construction of hydropower generating structures, water retaining structure and withdrawal of water by water users, which possesses a tremendous threat to the environment, ecology & aquatic life. Therefore a need arises to regulate the reservoirs for releasing the adequate water in the river throughout the year as well as a flushing flow once in a year. Thus environmental flows assessment is done in Lower Mahanadi sub-basin and recommended to provide the EFRs on average 33% of MAF with a range of Low flow 110% of mean low flow & High flow 23% of mean high flow to be ensured at any circumstances to avoid any degradation of river ecosystem. In the present study the assessment of the environmental flows on the basis of Tennant method, Tessman method, VMF method, Q90_Q50 method, Smakhtin method, low flow index (7Q10) method and FDC (EMC shifting technique) method using Global Environmental Flow Calculator (GEFC) software have been made.


1.Acreman M, Dunbar MJ.(2004).Defining environmental river flow requirements-a review. Hydrology & Earth system Sciences 8(5):861-876.
2.Davis R, Hirji R.(2003). Environmental flows: Concept and methods. Water Resources and Environment Technical Note C1.World Bank,Washington. DC.
3.Durbude DG, Jain CK, Singh O.(2014). Assessment of E-flows for a river in Southern India using Hydrological Index methods. Journal of Indian Water Resources Society 34(3).
4.Jha R, Sharma KD, Singh VP.(2008). Critical Appraisal of Methods for the Assessment of Environmental Flows and their Application in two river systems of India. KSCE Journal of Civil Engineering 12(3):213-219.
5.Joshi KD, Jha DN, Alam A.(2014).Environmental Flow requirements of River Sone: Impacts of low discharge on fisheries. Current Science 107(3):478-488.
6.Paster AV, Ludwig F, Biemans H, Hoff H.(2014). Accounting for environmental flow requirements in global water assessments. Hydrol Earth System Science 18:5041-5059.
7.Smakhtin VU, Shilpakar RL, Hughes DA.(2006).Hydrologybased assessment of environmental flows:an example from Nepal. Hydrological Sciences-Journal-des Sciences Hydrologiques 51(2).
8.Smakhtin VU, Anupthas M.(2006)-"An assessment of environmental flow requirements of Indian river Basins. IWMI Research Report 107.
9.Smakhtin VU, Eriyagama N.(2008).Developing a software package for global desktop assessment of environmental flows. Environmental Modelling &Software 23(12):1396-1406.
10.Tennant DL,(1976).Instream Flow Regimes for Fish, Wildlife, Recreation and Related Environment Resources.Fisheries 1(4):6- 10.
11.Tharme RE.(2003). A global perspective on environmental flow assessment: emerging trends in the development and application of environmental flow methodologies for rivers. River Research and Applications 19:397-441.

EFR, GIS, Tennant, Tessman, VMF, Q90_Q50, 7Q10, FDC method, GEFC software.