Droughts in the Sudano-Sahelian Ecological Zone of Nigeria: Implications for Agriculture and Water Resources Development
This study evaluates the extent and degree of severity of droughts in the Sudano- Sahelian Ecological Zone of Nigeria using rainfall data spanning a period of 60 years (1949- 2008) for eight meteorological stations in the zone. The Normalized Rainfall Index was used in depicting periods of different drought intensities in the region. The results revealed that the zone was characterized by larger extent of severe drought since the beginning of 1968 through the early 1970s, and then the 1980s in which the drought was so severe than any other decade in the study period. The late 1990s and the 2000s on the other hand have been witnessing a decrease in the number of drought occurrences in the zone. The mean absolute probability of mild, moderate and severe droughts for the zone was 0.13 (recurrence interval of 7.7 years), 0.11 (recurrence interval of 9.1 years), and 0.08 (recurrence interval of 12.5 years) respectively.
