Hydrological Method to Evaluate Environmental Flow (Case Study: Gharasou River, Ardabil)

Water flow management is one of the most important
parts of river engineering. Non-uniformity distribution of rainfall and
various flow demand with unreasonable flow management will be
caused destroyed of river ecosystem. Then, it is very serious to
determine ecosystem flow requirement. In this paper, Flow duration
curve indices method which has hydrological based was used to
evaluate environmental flow in Gharasou River, Ardabil, Iran. Using
flow duration curve, Q90 and Q95 for different return periods were
calculated. Their magnitude were determined as 1-day, 3-day, 7-day
and 30 day. According the second method, hydraulic alteration
indices often had low and medium range. In order to maintain river at
an acceptable ecological condition, minimum daily discharge of
index Q95 is 0.7 m3.s-1.

• Mehdi Fuladipanah
• Mehdi Jorabloo

• Ardabil
• Environmental flow
• Flow Duration Curve
• Gharasou River.

[1] N.L. Poff, J.D. Allan, M.B. Bain, J.R. Karr, K.L. Prestegaard, B.D. Richeter, R.E. Sparks, and J.C. Stromberg. “The Natural flow regime: a paradigm for river conservation and restoration”. Bioscience,1992,47 (11): 769-784.
[2] A. Arthington, S. Bunn, N. Pope, and R. Naiman, “The challenge of providing environmental flow rules to sustain river ecosystems”. Ecological Applications, 2006, 16(4), 1311-1318.
[3] R.E. Tharme. “A global perspective on environmental flow assessment: Emerging trends in the development and application of environmental flow methodologies for rivers”. River Research and Applications, 2003, 19(5-6), 397-441.
[4] P.J. Whiting. “Stream-flow necessary for environmental maintenance”.. Annual Review of Earth and Planetary Sciences, 2002, 30: 181-206.
[5] G.E.Petts“Water allocation to protect river ecosystems”. Regulated Rivers-Research & Management, 1996, 12:353-365.
[6] R.M. Vogel, N.M. Fennessey. “Flow duration curves. I. A new interpretation and confidence intervals. J. Water Resour. Plan. Manag., 1994, 120 (4): 485-504.
[7] J.C. Searcy. “Flow duration curves. United States Geological Survey”, Washington, DC, Water Supply Paper , 1959.
[8] J.W. Male, H. Ogawa. “Tradeoffs in water quality management”. J. Water Resour. Plan. Manag., 1984, ASCE 110 (4): 434–444.
[9] C.M. Alaouze. “Reservoir releases to uses with different reliability requirements”. Water Resour. Bull, 1989, 25 (6): 1163–1168.
[10] C.M. Alaouze. “Transferable water entitlements which satisfy heterogeneous risk preferences”. Aus. J. Agric. Econ., 1991, 35 (2): 197–208.
[11] C. Estes, J.F. Osborn. “Review and analysis of methods for quantifying instream flow requirements”. Water Resour. Bull., 1986, 22 (3), 389-398.
[12] R.M. Vogel, N.M. Fennessey. “Flow duration curves. II. A review of applications in water resource planning”. Water Resour. Bull., 1995, 31 (6), 1029–1039.