The Impact of Population Growth on Domestic Water Demand from Taleghan Reservoir under Climate Change Scenarios

Population growth can greatly impact on greenhouse gas emission pattern in the future. Considering the importance of population growth in climate change studies, the present research concentrates on the population growth of the Middle East in the late 21th century based on the IIASA population scenarios. Under the projections of A1-B1 scenario, the world’s population will grow up to 8.7 billion and according to A2 scenario it will be almost doubled by 2050. The results indicate that under both of these scenarios, which are considered among principle climate change scenarios, the population of the Middle-East would increase from 312 million in 1995 to 809 million and 2 billion, respectively by 2100. According to population rates assumed in these scenarios, the domestic water demand of Taleghan reservoir was estimated for the period of 2055 and 2100. The results indicated that under these two scenarios, by 2055 (2040-2069) the mean of monthly domestic water demand of the reservoir will be respectively increased by 80 and 161%. Furthermore, the analysis of the data for 2006-2011 revealed that during all these years as well as all their dry months (July – November), the total average of the domestic and agricultural water use rate has been greater than the average reservoir inflow rate, resulting in the decrease of the storage volume of the reservoir in these periods. Therefore, considering the severity of water shortage in this period, a reevaluation of the current reservoir management methods and formulation of a change adaptation plan seems to be essential.