VARIABILITY AND CHANGE ANALYSIS IN TEMPERATURE TIME SERIES AT KOLDA REGION, SENEGAL.

Abstract

This paper attempts to analyze spatial variability, temporal trends and identify the discontinuities in the maximum and minimum temperature’s time series. This study is based on annual and monthly data from the Kolda Weather Station over a 50-year period. Our approach is essentially structured according to 3 components: first, anomaly index and cumulative sums are calculated and finally, Mann-Kendall statistical test is performed. Considering anomaly index, results highlight four categories of periods both annual and monthly scale: very hot, hot, very cold and cold for the maximums and the minimums. The analysis indicated that minimums increased significantly more than maximums. Regarding the CUSUM, results showed a downward trend for maximums and upwards for minimums on an annual and monthly basis. The dates of these breaks are 2001 and May for maximums and 1975 and February for minimums respectively at annual and monthly scale. Regarding Mann Kendall test, results show a significant downward and upwards trend respectively for maximums and minimums. On a monthly scale, we make the same observations except that the trend is not significant for minimums. It can be concluded that the strong warming experienced by the Kolda region in recent years is largely conditioned by the increase in minimum annual temperature.

Keywords

• variability
• sift
• trend
• global warming
• productive water
• greenhouse gases
• regional levels