Determination of environmental water requirement of Miankaleh wetland

Miankaleh international wetland, located in Mazandaran province, is of high importance in terms of management of water resources and preserving the unique ecosystems and biodiversity. This study attempts to determine the environmental water requirement of Miankaleh wetland. Two major sources of water supply for upper basin of Miankaleh wetland, including Siyah Ab and Quz Mahaleh rivers, were chosen to determine the environmental water requirement. First, the duration curve method (hydrological method) was used to determine the environmental flow of the rivers. Then, the comprehensive approach was used to survey the abundance of aquatic bird species population and their dependence on water. Using a combination of these two methods, the environmental water requirement of the wetland was estimated at the estuary of the rivers feeding it. The results indicate that, based on duration curve method, the minimum input flows from Siyah Ab and Quz Mahaleh rivers to Miankaleh wetland were 0.578 and 0.054 m3/s respectively. Moreover, considering the aquatic birds in the comprehensive approach, the minimum input flows from Siyah Ab and Quz Mahaleh rivers to the wetland were estimated to be 2.163 and 0.099 m3/s respectively. Miankaleh wetland can be preserved in a good condition (Q75) by maintaining the minimum input flows from to it. Moreover, by maintaining the minimum input flows of about 0.325 and 0.015 m3/s from Siyah Ab and Quz Mahaleh rivers respectively, the wetland is preserved in a relatively good condition (Q90).