Author(s): Elnaz Zehtabian, Ardalan Izadi, Farhad Yazdandoost
Linked Author(s): Ardalan Izadi
Keywords: Integrated Water Resources Management (IWRM), Environmental Flow Assessment (EFA), Zayandeh Rood River, hydrological method, hydraulic rating method.
Abstract: Biodiversity of rivers are often exposed to multiple threats, making river systems vulnerable ecosystems, while rapid increase of population, agricultural and industrial developments exert severe pressure on policy makers to overlook the environmental requirements of river systems. To address this challenge, it is imperative to include the Environmental Flow Assessment (EFA) as an integral part of river basin management. Unfortunately, less attention has been paid to EFA in arid and semi-arid regions where river environmental problems tend to exacerbate as a result of prevailing water shortages. Zayandeh Rood River located in the arid and semi-arid region of central Iran has been selected as the case study here. Hydrological (Tennant and Flow Duration Curve-FDC) and Hydraulic rating method (Wetted perimeter method) have been employed here. The results show that while the Tennant method and the FDC method report the same values at 13. 9 M3/s as the need of environmental flow, the results based on the plotted curve in the wetted perimeter method reveal the amount of EF around 22. Given the important impact of the environmental flow allocations on the IWRM model of the river basin, it is imperative to estimate EF as accurately as possible for inaccuracies and uncertainties may impose huge risks both to the environmental conditions and the water resources allocation decisions
Year: 2017