Precipitation Patterns in West Africa

Abstract

A regional precipitation analysis from a total of 813 recording stations in 11 West African countries for the drought period 1968?75 is presented. Results illustrate the severity and extent of meteorological drought which prevailed throughout the region and reached greatest magnitude in 1973. In that year, the critical 300?400 mm zone of annual rainfall was at least 200 km south of its normal position resulting in major crop failures in several sub-Saharan countries. In Nigeria, 50-year records of rainfall from 28 stations were examined to study both temporal and spatial distributions. In the northern Sahelian zone of Nigeria, two prolonged drought periods were observed (i.e., 1940?s and 1968?76). This detailed analysis further demonstrated the strong relationship between rainfall in the Sahelian region and the position of the Intertropical Convergence Zone (ITCZ). However, there were years during which widespread below-normal rainfall occur-red throughout most of Nigeria which supports previous studies linking large-scale tropical circulation features to rainfall in the Sahel.