Spatio-Temporal Patterns of Rainfall Variability for Wet Season over Togo in West Africa

Climate change is affecting rainfall variability. This paper investigated the June-September (JJAS) rainfall variability using reanalyzed and observed da-tasets from 1976 to 2015 in Togo. The rotated empirical orthogonal function (REOF) method was used to get the distribution patterns of JJAS rainfall. The Mann-Kendall (MK) statistic was also used to detect temporal trend of the ro-tated principal component time series (RPCs) that represent the modes of posi-tive loadings. The REOF method has revealed four significant patterns that ex-plained 65.1% of the total variance; the first, the second and the fourth REOF modes exhibit mainly positive loadings, whereas the third exhibits negative loadings. The first mode (REOF1) represents mainly the southern part of Togo; the second mode (REOF2) represents the northern part, the third mode (REOF3) represents the western part and the fourth (REOF4) represents the north-eastern part of Togo. The Mann-Kendall test has revealed an increasing and significant trend of rainfall in the northern region of Togo. In contrast, the trends were not significant in the southern and north-eastern parts of the coun-try. These results form a basis on which adaptation strategies may be taken in this region with high rainfall variability.