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DIIS WORKING PAPER 2013:17
Lyon and DeWitt conclude that since 1999
the East Africa region has experienced a de-
cline in precipitation during the long rainy
season, which has continued since (Lyon and
DeWItt, 2012:4). Funk et al. (2008) state that
East Africa has seen precipitation decline
since 1979 (Funk et al., 2008:11082). Fur-
thermore, overall future climate projections
for East Africa show scientic disagreement
over total rainfall. Funk et al. (2008) suggest
that East Africa will expect a decline in total
rainfall, at least until 2030. The authors use
climate relationship data as opposed to raw
simulations (Funk et al., 2008:11083, 11085).
Conversely, the IPCC report Region Climate
Projections suggests that there is likely to be an
increase in annual mean rainfall in the future
(Christensen, 2007:850). There are, howev-
er, disagreements among scientists. Accord-
ing to McSweeney et al. (2008) observations
of rainfall over Uganda do show statistically
signicant decreasing trends in annual and
March to May rainfall (McSweeney et al.
2008:2).
According to a Climate Policy Paper
(2012), prepared by the Climate Change Unit
within the Ministry of Water and Environ-
ment in Uganda, changes have been observed
in rainfall patterns in Uganda. Rainfall has
become lower, more unreliable and uneven-
ly distributed, and where rain does fall, it is
heavier and more violent. In general, wet-
ter areas are tending to become wetter and
droughts more frequent. The main concern
is not the total amount of rain, but instead
its distribution, seasonality and intensity, the
policy paper concludes (GoU Climate Policy
Paper, 2012:5).
Trends in the variation in precipitation
based on daily rainfall data are, however,
mixed. McSweeney writes that there is no
signicant trend towards heavier and more
extreme rainfall events (McSweeney et al.
2008:2). Others report that rainfall in Ugan-
da has become more unreliable and uneven-
ly distributed (IGAD, 2010). An increase in
the intensities and frequency of heavy rains,
oods and landslides in highland areas, as
well as outbreaks of associated waterborne
diseases associated with the oods, were
also observed and conrmed by a Participa-
tory Rural Appraisal (NEMA, 2008). Recent
years have seen erratic onsets and ends to the
rainy seasons, and rainfall has been heavier
and more violent (GoU, 2007; MWE, 2010).
These are being followed by long droughts,
which are becoming more and more fre-
quent. El Nino Southern Oscillation (ENSO)
events have also been observed to be shorter
and more irregular (IGAD, 2010).
Shongwe et al. 2011 carried out a study
of possible changes in the intensity of mean
and extreme precipitation rates in East Afri-
ca. They state that ‘Evidence in support of
a future positive shift in the rainfall distri-
bution under global warming has been pre-
sented for most models, with only a single
model simulating a trend to less rain’. They
also conclude that ‘It is physically reasona-
ble, therefore, to conclude from this ocean–
atmosphere coupling pattern that global
warming could enhance the likelihood of
anomalously strong short rains’ (Shongwe et
al, 2010:3728f).
Since 2000, extreme rainfall conditions
have been regularly experienced in eastern
Uganda, where there has been an increase
of approximately 1500 mm in precipitation
in the December to January rainy season
(NEMA, 2008). Teso region has particular-
ly been affected by these trends. According
to the Uganda Department of Meteorology,
rainfall seasons have become more variable as
depicted by the analysis of cumulative average
ten-day totals. Although western, central and
northern Uganda experienced good rainfall,