Spatial and Intrannual Variability of Rainfall in South Region of the Mozambique, Southern Africa

Abstract Studies on the climatology of rainfall in the South Region of Mozambique (SRM) are essential for the planning of human activities, with emphasis on agriculture. Therefore, the diagnosis of seasonal and monthly trends in rainfall is necessary, mainly because it is a region with an irregular spatial-temporal distribution of rainfall. The variation of the monthly and seasonal rainfall in SRM was analyzed based on long-term rainfall series (45 years, 1960-2004). The cluster analysis (Ward's method) was applied to identify regions with homogeneous monthly rainfall. Based on the cluster analysis, three groups of stations with homogeneous monthly rainfall (G1, G2, and G3) and three stations that were not grouped (NDg) were identified. Rainfall showed a negative gradient toward G1 to G3 (northeast - southwest), and total among the largest in NDg stations (near to coast). The rainy season pattern was similar, with greater length in the seasons of the G1 and NDg, smaller in G3. The seasonal and monthly variability of rainfall in SRM is conditioned by Tropical Cyclones, Frontal Systems and warm Current of the Mozambique Channel, while the spatial variability is mainly conditioned by the Intertropical Convergence Zone.