Hydrological Assessment of Environmental Flow of Rivers

Freshwater resources are assumed as one of the vital needs of all the living creatures. As times go on the human needs of water for his activities rise up. The human and ecosystems’ need to water caused a growing competition for water between them. Due to this fact, a requirement to develop methods of assessment of environmental flow of river arose. These methods are categorized to some groups that one of the most important and widely applicable categories is allocated to hydrological methods. The hydrological methods are based on river and fish characteristics and river’s flow and water level that maintain the river in a favorable condition. One of these methods is Tennent method that has been used widely all over the world. Considering this method and the condition of ecosystems caused some changes in that method. This has resulted in providing new methods such as Tessman method, Arkansas, flow duration curves (FDC), aquatic base flow, percentage of flow (POF) method, sustainability boundary approach (SBA), Smakhtin and Hoppe method that is brought in this study.

Keywords:

Environmental flow , rivers , Tennant , Smakhtin , Flow Duration Curve