4 Climate Change and Water Resources in West Africa …
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Fig. 12 Evolution of
Pettitt’s test results in
Senegal from 1921 to 2016
Fig. 13 Evolution of Lee
and Heghinian’s test results
in Senegal from 1921 to 2016
Bayesian’s method results
A posteriori probability density function mode of the
break point position: 0,7587 in 1967
639.4 mm for the second—a rainfall decrease of 192.6 mm (23.1%). The rainiest
years were 1927, 1936, 1950, and 1958, with respective rainfalls of 1076.5 mm,
1016.6 mm, 1011.2, mm and 1026 mm. The driest years were 1972, 1977, 1980, and
1983, with respective rainfalls of 488.1 mm, 456.3 mm, 475.8 mm, and 414.9 mm.
The difference between the wettest year and the driest year was 661.6 mm. The dry
period, the beginning of which was confirmed in 1968 by the segmentation of Hubert,
was subdivided into two sub-periods, the first extending from 1968 to 1998 with an
average rainfall of 603.3 mm, and the second from 1999 to 2016 with an average
of 701.6 mm. The 1999–2016 sub-period represents a slight increase in rainfall of
98.3 mm (14%) compared with the previous period. Over the entire series, 47 years