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
