RAINFALL VARIABILITY ANALYSIS IN BURUNDI FOR AGRICULTURAL PRODUCTION

Abstract

In Burundi, agriculture accounts for approximatively 80% of the economically active population and it remains a very important economic sector. In this part of the world rainfed agriculture is largely dominant; food security and income of rural populations are vulnerable to rainfall variability. Therefore, rainfall being an important climatic element in crop production in Burundi, the main objective of this research was to analyze the spatial and temporal variability of rainfall in Burundi. For this purpose, 16 meteorological stations with 30 years of data record have been used. Investigation of monthly, seasonal and annual rainfall variability using different methods reveals that there is spatial variability of rainfall in Burundi. The results indicated that temporal distribution of annual rainfall didn't show significant change within the period considered. The seasonal variability analysis shows that the temporal distribution of the two main seasons is variable from year to year. From monthly rainfall variability analysis, the months of May, June, July, August, September and October are characterized by high variability in rainfall data series indicating low reliability of rainfall during these periods. The remaining months of the year showed less to moderate variability. Another observation is that rainfall variation increases as the time becomes shorter, i.e. the variability is higher when evaluated on monthly basis than on annual basis. Trend detection analysis conducted using Mann-Kendall non-parametric test on monthly rainfall series with high variability showed negative trend indicating the decrease in precipitation, but this trend was statistically significant for some months and stations. Because of variability of rainfall in space within the study