Impact Assessment of Environmental Demand in Design and Operation of Dams using Simulation Algorithm

The use of simulation tools for operation of surface water reservoirs has become one of the most serious challenges in all over the world. This study aims to investigate the performance of BA, SPA and MSPA algorithms in both design and operation phase of a reservoir.

To this end, using data of hydrometric station upstream of Zarrinehrood Dam and SPA and BA simulation algorithms, the reservoir capacity in 100% reliability mode of Zarrinehrood Dam and SPA and BA simulation algorithms, the reservoir volume in 100% reliability mode has been designed for two different scenarios of downstream demand. The first scenario includes drinking and agricultural demand (2D) and the second scenario includes triple drinking, agricultural and environmental demand (3D). Since the realization of 100% reliability is not always justifiable, in order to simultaneously apply the two indicators of reliability and vulnerability in the design of the reservoir, the modified SPA method (MSPA) and the first demand scenario were used. In this regard, considering the 98% reliability and three levels of vulnerability, the models MSPA-1 (10% vulnerability), MSPA-2 (20% vulnerability) and MSPA-3 (30% vulnerability) It was considered to design the volume of the reservoir. Finally, to evaluate the performance of the reservoir in the operation stage, the BRC and SOP operation rules as well as the reservoir performance indicators have been used.

The design results with SPA and BA methods showed that the volume of the reservoir in 3D mode has increased about 4 times compared to 2D mode, so the application of 2D scenario in design from an economic point of view will be more justifiable. The use of MSPA-1 and MSPA-3 methods compared to SPA in the design phase has reduced the reservoir volume by 11 and 25%, respectively.

The results of reservoir performance indices showed that the SOP method increased compared to the BRC method for all three design methods and the MSPA method decreased between the first and third modes and there was little change between the second and third modes.