Drought variability, changes and hot spots across the African continent during the historical period (1928–2017)
In particular, researchers aim to (1) detect modes of drought variability by applying a rotated empirical orthogonal function (REOF) to the SPI values; (2) quantify recent changes in drought characteristics (e.g., maximum drought duration, frequency and severity) and (3) identify drought hot spots and how seasonal variability contributes to determining drought hot spots.
The publication concludes with the following main findings:
- Based on the REOF method, we identified five main regions in Africa with distinct spatial and temporal drought features: Sahel, East Africa, East Southern Africa, West Southern Africa and Gulf of Guinea;
- Changes in precipitation and drought characteristics show a persistent drying tendency and robust increases of drought duration, frequency and severity in areas extending over most Sahel countries, the Gulfof Guinea and some areas of Southern Africa, including Madagascar, during both the intermediate and the recent past (compared to the far past period);
- Robust features of drought hotspots are identified in the intermediate and recent past periods and correspond to localized areas mainly in the Sahel (central Mali and Niger, northern Nigeria, southern Chad and over Sudan) during the intermedi-ate past and over Central Africa (i.e., central and northeastern DRC), Southern Africa (i.e., Zambia, Botswana and Mozambique) and in Madagascar during the recent past.