106
S. Kusangaya et al.
Table 2
(continued)
Author (s)
Period of analysis
Study area
Degree of change (Conclusion)
Kane (2009)
1900–1998
South Africa
Annual values showed considerable
year-to-year fluctuations (50−200% of the
mean), while five-year running means showed
long-term fluctuations (75−150% of the mean)
Running means over 21 years did not indicate
linear trends, upwards or downwards. Instead,
considerable oscillations were seen with
magnitudes different in different regions
(5−25%)
In the largest part of South Africa, there has
been no real evidence of changes in rainfall
over the last century, there are, however, some
identifiable areas, where significant changes in
certain characteristics of rainfall have occurred
over the period 1910 to 2004
Conway et al. (2009)
1901–2001
Africa
+ southern Africa
High inter-annual variability in southern Africa
Modest inter-annual rainfall and river flow
variability and quite low runoff coefficients
Mean rainfall between 1931–1960 and
1961–1990 is fairly stable, as is river flow in the
Zambezi, whilst in the Okavango it recorded a
14% increase
(continued)