COMPARATIVE STUDY OF FLOW REGIMES FOR THE EXAMINATION OF ENVIRONMENTAL FLOWS

The management of the water resources is an important issue in the countries around the world because it depends on many variables. Prior to the growing environmental awareness, flow rate and regime are critical components of water supply, water quality, and the ecological integrity of river systems. Environmental flow may be described as the required stream flow quantity to support the ecological activity in a river system. While environmental flow assessment provides protection and use balance over the water resources and it also reduces the natural and artificial effects that caused of deterioration of the natural condition of the rivers. There are only a few environmental flow assessment studies in Turkey. In this paper, daily flow data has been used to determine the flow regimes in order to have some idea about the environmental flow. For this purpose, common methods such as original Tennant method, modified Tennant method, wetted perimeter method, 7Q10 and Q95 have been examined. Daily flow data has been obtained from three gauging stations located in Great Menderes Basin. The first one (07-30) is unregulated, the second is regulated (07-04) and the third one is indirectly regulated (07-71) gauging stations. As a result of this study, particular methods have more reliability and might be more appropriate for each case. The modified Tennant method could be selected as the most practical method for the measured data of flow rates in unregulated gauging station. Q95 method can be used for the other two stations.