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Drought in Africa
Drought Scenario and Impacts
Rain-dependent agricultural activities, including livestock production, form the fundamental economic base of many African countries. Water is permanently available from a few major river basins and several inland freshwater lakes. The major African rivers traverse several countries and this calls for regional strategies in their water uses. Drought in Africa is often associated with far-reaching socioeconomic miseries that include low agricultural production leading to lack of food, famine, malnutrition and associated diseases; loss of life and property; low hydroelectric power generation; reduced industrial production; and environmental degradation, among others.
The lifestyles of some communities change as they are often forced to adjust to prevailing conditions. For example, people and animals are forced to migrate in search of water and food. This enhances conflicts between communities, and between people and animals, over limited water resources and pasture. Electricity rationing becomes the order of the day in countries which rely on hydroelectric power generation. Lack of power and raw materials leads to closures of industries, dismissal of workers, reduction in exports and enormous loss in foreign earnings that are critical for emergency services.
Available records show that droughts are common in all parts of Africa, and there is no month or season when the whole continent is drought-free. The causes of droughts in Africa, like other parts of the world, are anomalies in the general circulation at specific locations. The causes of such anomalies have been linked to variations in global and regional climate systems. In Africa, the major systems that have been linked to regional and local climate include, among others:
- Inter Tropical Convergence Zone (ITCZ)
- Maritime semi-permanent anticyclonic systems, especially those centered around the Azores, Mascarene, St Hellena Highs and the Arabian High
- Inter-hemispheric monsoonal wind systems
- African jetstreams
- Squall lines
- Easterly-westerly wave perturbations
- Tropical cyclones
- Extratropical weather systems such as frontal and blocking systems, and
- Teleconnections with global sea surface temperatures; El Niņo Southern Oscillation; Quasi-biennial Oscillation; North Atlantic Oscillation; and intra-seasonal circulation (Julian-Madden wave).
Africa has complex topography that includes the Great Rift Valley, running north to south across the continent with chains of parallel mountains. There are also many large inland lakes which serve as local sources of moisture for rainfall generation when the moisture transport by the large-scale winds are retarded. These complex regional features often modify the large-scale flow over Africa. Thus it is often difficult for an extreme climate event such as flood or drought to cover all sub-regions of the continent.
Mitigation Measures and Initiatives
Risk zoning, climate monitoring, prediction and timely early warning of extreme climate events are the best strategies for mitigating the negative impacts of such events and also for taking advantage of the good years. Optimum use of climate information in disaster management, however, requires an efficient and well-integrated national and regional disaster management policy.
Under the auspices of WMO and UNDP, in 1989, 24 countries in eastern and southern Africa established a regional Drought Monitoring Centre (DMC) in Nairobi and a sub-centre in Harare. The main objective of the DMC was to contribute to the monitoring, prediction, early warning and mitigation of the adverse impacts of extreme climate events on agricultural production and food security, water resources, energy and health, among other socioeconomic sectors. At the end of the UNDP-funded project in 1998, and due to increased demand for climate information and prediction services, DMC Nairobi and DMC Harare began operating independently.
DMC Nairobi serves ten countries in the Greater Horn of Africa under the auspices of the member states of the Inter Governmental Authority on Development (IGAD), while DMC Harare is responsible for 14 countries in southern Africa, under the auspices of the member states of the Southern Africa Development Cooperation (SADC). Details of the DMCs can be obtained from the DMC Nairobi website at
www.dmcn.org. Other major climate and application centers in Africa include the African Centre for Meteorological Applications for Development (ACMAD) and the Agro-Hydrometeorological Centre (AGRHYMET), both located in Niamey, Niger.
Prof L A Ogallo is Coordinator at the Drought Monitoring Centre Nairobi, Kenya, and can be contacted at
laban.ogallo@meteo.go.ke
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