Rainfall variability in Congo-Brazzaville

Description

The interannual variability of rainfall amounts and rainy days is analyzed from synoptic stations located in different climatic zones of Congo-Brazzaville. The annual and seasonal rainfall evolution is appreciated using standardized indices. Trends were examined based on the non-parametric Mann-Kendall test. A majority of negative anomalies is recorded during the 1930s and 1940s. The decade 1950 shows mainly positive anomalies with the exception of 1958 which records a general precipitation deficit all across Congo. The decade 1960 is characterized by precipitations excess over the whole of Congo. Since 1980’s the largest rainfall deficit (about 10-20%). The transition between positive and negative anomalies decades is not uniform across Congo. Since about the 1980s, annual precipitation at northern stations has decreased significantly. In the south, the decrease rainfall observed season March-May.