From headwater tributaries to international river: Observing and adapting to climate variability and change in the Nile basin

Egypt is almost totally dependent upon water that originates from the upstream headwaters of the Nile in the humid Ethiopian and East African highlands. Analysis of rainfall and river flow records during the 20th century demonstrates high levels of interannual and interdecadal variability. This is experienced locally and regionally in the headwater regions of the Nile and internationally through its effects on downstream Nile flows in Sudan and Egypt. Examples of climate variability are presented from areas in the basin where it exerts a strong influence on society; the Ethiopian highlands (links with food security), Lake Victoria (management of non-stationary lake levels) and Egypt (exposure to interdecadal variability of Nile flows). These examples reveal adaptations across various scales by individuals and institutions acting alongside other social and economic considerations. Water resources management in the downstream riparian Egypt has involved institutional level reactive adaptations to prolonged periods of low and high Nile flows. Observed responses include the establishment of more robust contingency planning and early warning systems alongside strategic assessment of water use and planning in response to low flows during the 1980s. In the 1990s high flows have enabled Egypt to pursue opportunistic policies to expand irrigation. These policies are embedded in wider sociopolitical and economic considerations but increase Egypt's exposure and sensitivity to climate driven fluctuations in Nile flows. Analysis of climate change projections for the region shows there is no clear indication of how Nile flows will be affected because of uncertainty about future rainfall patterns in the basin. In many instances the most appropriate entry point for adaptation to climate change will be coping with climate variability and will play out against the certainty of looming national water scarcity in Egypt due to rapid population growth and its possible exacerbation by water demands from upstream riparians. (C) 2005 Elsevier Ltd. All rights reserved.