Evaluation of Climate Change Impacts on the Operation Rule Curves of a Dam (Case Study: Dez Dam)

this study, a methodology is proposed to investigate the hypothesis that states the needs to change dam reservoir rule curves for the future and under climate change conditions. To adapt values of reservoir release to future climatic conditions a model is proposed for evaluation of climate change impacts on reservoir performance. The proposed methodology included LARS-WG model for transformation of CGCM model output under three emission scenarios of A1B, A2, B1 to regional scale, IHACRES model for simulating inflow stream to reservoir for future period of 2017-2030 validated using baseline data (1993-2006), and the evolutionary optimization model of Genetic Algorithms (GA), whcih is used to optimize reservoir operation. Finally, rule curve of dam operation was calculated for the past and future period according to three emission scenarios of A1B, A2, B1. Applying the proposed methodology in determination of rule curve in Dez Dam located in Khouzestan province showed that despite the modification of rule curve in order to achieve less values of shortages under climate change conditions for the future period, water supply security index would nevertheless decrease. The reduction percent would be between 1.7 to 5.7 percent under scenarios A2, A1B and B1. If the rule curve is not modified, higher values of shortages would occure. Finally, it should be mentioned that ignoring the effects of climate change and using baseline period’s operation rules for future period will reduce water supply security percentage.