University of Tehran Press Journal of Ecohydrology 2423-6098 5 3 2018 09 23 Determination of the Environmental Flow Requirements for the SefidRud River, IRAN Determination of the Environmental Flow Requirements for the SefidRud River, IRAN 753 762 67502 10.22059/ije.2018.240350.711 FA Fatemeh Fattahpour Former MSc Student of Water Resources Engineering, Department of Irrigation and Reclamation Engineering, University of Tehran Kumars Ebrahimi Professor of Irrigation and Reclamation Engineering Department. University of Tehran 0000-0002-9914-4383 Sogand Bayat Department of Irrigation and Reclamation Engineering, University of Tehran, Karaj, Iran Journal Article 2017 08 22 Environmental Flows describes the timing, quality, and quantity of water flows required to sustain ecosystems, human well-being and livelihoods that depend upon them. A review of the present status of environmental flow methodologies revealed the existence of 4 differentiated methodologies. The main purpose of this paper is to assess common methods of environmental flow requirements. According to the standards of the Ministry of Energy of Iran, Tennant introduced as the base method for determining the environmental flows. This method together with wetted perimeter method with three different ideas is applied to the SefidRud. Also, the habitat simulation method, which is a part of the ecological method, is applied to SefidRud River too. Huso Huso fish was chosen as the species river target in this research study. The advantages and limitations of the above mentioned methods are presented as a part of results. 20% and 30% of the annual average flows are suggested for maintaining river health in poor and good conditions, respectively. The combined simulation method habitats and the maximum curvature of the wetted perimeter are recommended as a native method for SefidRud River to determine the minimum ecological flow and improve the ecosystem of the studied river. Environmental Flows describes the timing, quality, and quantity of water flows required to sustain ecosystems, human well-being and livelihoods that depend upon them. A review of the present status of environmental flow methodologies revealed the existence of 4 differentiated methodologies. The main purpose of this paper is to assess common methods of environmental flow requirements. According to the standards of the Ministry of Energy of Iran, Tennant introduced as the base method for determining the environmental flows. This method together with wetted perimeter method with three different ideas is applied to the SefidRud. Also, the habitat simulation method, which is a part of the ecological method, is applied to SefidRud River too. Huso Huso fish was chosen as the species river target in this research study. The advantages and limitations of the above mentioned methods are presented as a part of results. 20% and 30% of the annual average flows are suggested for maintaining river health in poor and good conditions, respectively. The combined simulation method habitats and the maximum curvature of the wetted perimeter are recommended as a native method for SefidRud River to determine the minimum ecological flow and improve the ecosystem of the studied river. https://ije.ut.ac.ir/article_67502_3d43c36374451091416e3baf7eb8147e.pdf