Extreme climate events such as drought and floods with severe impacts over the Greater Horn of Africa (GHA) have been on the rise over the past decades. These events negatively impact the regional ecosystem, livelihood, and economy which heavily depends on rain-fed agriculture, while in the energy sector largely depends on hydropower, thus shifts and variability in rainfall and temperature could hinder the development and economic growth of the region. Therefore, assessing the risk/monitoring of these events in the past, present and future are critical for community resilience and understanding of the Water-Energy-Food-Ecosystem nexus. We used the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) methods with the Climate Research Unit and CORDEX datasets to assess the level of drought and flood risk. This was done for the GHA region and further focusing on two basins over the region: Lake Victoria and the Blue Nile basins. Hydrological drought time intervals were utilized. Preliminary results show that, at the regional scale, there were more extreme wet conditions before the 1970s with 1961 observed as the wettest on record. After the ’70s, more dry conditions were observed with 1984 and 2011 noted as the driest years. The periodicity of these dry/wet conditions was observed to be three years which can be attributed to the El-Nino Southern Oscillation. An increasing trend of abnormal wet conditions from 1961 to current was observed over Lake Victoria basin. However, the Blue Nile basin has recorded more dry conditions in the recent past, thus reducing inflows into the Nile River. A projection into the future indicates that the region is likely to experience high frequency of dry/wet conditions for both RCP45 and RCP85 covering a wide geographical area. Thus, these results here can support decision-making processes through scenarios-based-analysis at the basin and regional levels.
- Annex 58: Atheru Z., 2020. Inception report. ACEWATER2 report JRC122680 (Component of deliverable)
- Annex 59: Atheru Z., 2020. Climate variability and extreme events report. ACEWATER2 report JRC122680 (Main deliverable)
- Annex 60: Atheru Z., 2020. Database (colllection of relevant meteo datasets over the Blue Nile and lake Victoria basin). ACEWATER2 report JRC122680 (Component of deliverable)