Calculation of environmental water requirement in Great Karoun basin and upper Karoun sub-basin

The environmental requirement of the river is the amount of water to maintain natural ecological conditions and health of quality of the river water. In this study, to estimate the environmental water requirement of Karoun River, Dez, Great Karoun and Beheshtabad sub-basin (upper Karoun) using hydrological Montana method and offers based on frequency analysis of hydrological flow normally and use tenths. The estimates shows the environmental water requirement is 4800 for Karoun branch, 3000 for Dez, 8000 for Great Karoon basin and 800 million cubic meters per year for Beheshtabad sub-basin that it means there is no surplus water to transfer from dams and Beheshtabad,s tunnels to the central plateau so this sub-basin is only capable to supply it,s consumption , water transferring by Koohrang tunnel and environmental needs of its own.