Optimum Operation of Reservoirs in the Karkheh Basin in Iran Considering Impacts of Non-integrated Development and Climate Change

摘要

Karkheh river basin in the southwest of Iran will contain 40 dams with 8326 million cubic meters (MCM) storage volume, of which seven will produce hydro-energy according to the water master plan of Karkheh river basin (KRB). Non-integrated upstream development and water allocation in Karkheh river basin, construction of large dams and climate change will change the operation conditions of the KRB system in developed stages. The focus of this paper is to assess the impact of these new conditions on the KRB system performance if current policy is followed and also how coordinated multi-reservoir operation can adjust and reduce the negative impacts onthissystem. Informing the water and energy-sector decision-makers about the KRB system performance if current practice or coordinated operation is adopted will be the objective of this paper. A basin-wide hydro-system multi-reservoir operation optimization model is developed to model the dams' coordinated operation, water allocation and their spatial-temporal interactions, while minimizing the slacks in supplying water and energy demand targets. A basin-wide multi-reservoir system model is developed to simulate the current practice. Several scenarios of climate change and upstream water allocation are considered and evaluated. Six main dams with storage volume greater than 1600 MCM are considered and analyzed using the optimization and simulation model. The results show that irrigation water supply to Karkheh downstream reliability drops to 3% if current practices are followed when all the system is developed, while by thecoordination, the reliability increases just to 21%. As expected, thecoordinated operation of the systemshows less deviation in comparison with current practice. In addition, the reservoir operation coordination in KRB system can increase the water supply by 20%, energy production by 5% and inflow to the Hoor-Al-Azim wetland by 50% in comparison with current practice reservoir operation.