Assessing the Impacts of Climate Changes on the Eastern Nile Flow at Aswan

The Eastern Nile River Basin is currently experiencing new developments of 13 dams and reservoirs; both in Ethiopia and in Sudan to full utilize the basin for electricity generating and irrigation to face the population growth. These dams are 5 dams (Gambella, Baro1, Baro 2, Geba A and GebaR) on Baro-AkoboSobat-White Nile, 3 dams (Metema Dam, Rumela Dam and Humera Dam) on Tekeze-Setit-Atbara and 4 dams (Mandaya, Karadopi, Beko Abo and Grand Ethiopian Renaissance Dam) on Blue Nile and one dam (Kajbar Dam) on Main Nile. Egypt and Sudan are hot arid and semiarid countries, almost vitally relying on the Nile water as water source, with water demand in Egypt alone set to increase. These developments will strongly affect the water flow at Aswan. Therefore, it is needed to take into account these developments for Egyptian water right. In addition, the impacts of climate change for the whole basin development and management for near future (2011-2040), intermediate future (2041 – 2070) and far future (2071 – 2100) on the inflow, evaporation and energy production at High Aswan Dam have been taken into consideration. RIBASIM Model has been used in this study to simulate the water system in the Eastern Nile Basin. The model has advanced flexible features in operating goals for several different types of demand (hydro-power, irrigation, etc.) and the option to manage the system with priority to different demands. The baseline models is configured with the existing infrastructure and calibrated with historical hydrological regime. The model performed very well and satisfactory simulates the monthly flow distribution. The Nash-Sutcliffe efficiency and coefficient of determination accuracy were 0.95 for most of the gauge stations, Where, Mean Relative Bias (PBAIS) and Root Mean Square error (RMSE) varies between 0.015-28, 29-555m/s, respectively. 32 scenarios have been considered to assess the impacts of climate change on the Eastern Nile River. These scenarios comprise baseline scenario, 14 development scenarios, 18 combined / management scenarios (17 individual covering basin and 1 overall basin) during the current century and 4 climate change scenarios 2011–2040 (near future), 2041-2070 (intermediate future) and 2071-2100 (far future), respectively. 10 dams out of the 13 have a negative impact to the inflow at Aswan, The development and management of 10 dams on the Eastern Nile would reduce average annual the inflow, evaporation and energy production at Lake Nasser/ HAD by 18%, 4% and 4%, respectively. However, climate change can force these Lake Nasser to be drier. The average annual inflow reductions at High Aswan Dam due to climate change are estimated to be 24%, 35% and 36% for near future (2011-2040), intermediate future (2041-2070) and far future (2071 -2100), respectively. [Hany Mostafa, Hazem Saleh, Mahmoud El Sheikh and Khaled Kheireldin. Assessing the Impacts of Climate Changes on the Eastern Nile Flow at Aswan. J Am Sci 2016;12(1):1-9]. (ISSN: 1545-1003). http://www.jofamericanscience.org. 1. doi:10.7537/marsjas120116.01. Keyword: RIBASIM, Hydrological mode, Calibration, Validation, Climate changes, Eastern Nile and Aswan