Ecological flow assessment using hydrological method and validation through GIS application

• Published in: Groundwater for sustainable development Vol. 19; p. 100841
• Main Authors: Prakasam, C., Saravanan, R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2022
• Subjects: Environmental flow; Flow duration curve; GIS applications; Hydrology method; Hydropower project; Hydrology method; GIS applications; Hydropower project; Environmental flow; Flow duration curve
• ISSN: 2352-801X; 2352-801X
• DOI: 10.1016/j.gsd.2022.100841

Environmental flow is the minimal flow that has to be discharged maintain healthy ecosystem. National Green Tribunal (NGT) law states 15% of the average lean season flow as the environmental flow. Inability to maintain may incite a decline in the health of the ecosystem. The research work evaluates the sufficiency of the NGT's law on environmental flow using the hydrology method. The proposed work evaluates the environmental flow requirements for Larji Hydropower Dam (126 MW), Kullu, Himachal Pradesh. Traditionally to validate the environmental flow requirement results, one of the environmental flow methods will be used. Here to aid the results of the environmental flow assessment, Geographic Information System applications has been used. The environmental flow requirement evaluated from the Flow Duration Curve is more than the 15% of the average lean season flow. The attempted work concludes that up to 20–25% of average lean season flow shall be maintained as environmental flow. For the current ecosystem, the result has an added advantage and is beneficial to the existing ecosystem. [Display omitted] •The work attempts at evaluating the NGT's order for environmental flow.•The Q95 value from the FDC results is more than the 15% environmental flow norms.•The suggestion is 25–30% of average lean season flow as e-flow.•The results were compared and validated with the GIS results.