Africa´s
water problem is complex, but I´ll try to outline some of its most important
physical and socio-economic characteristics. Firstly, topography has a
significant effect on water distribution across Africa. Large areas of eastern
and southern Africa lie in rather high altitude, approximately 1000 m above sea
level, whereas landscapes in northern and western Africa are generally lower
(Taylor 2004). These physical characteristics have a remarkable
effect on local rainfall and water distribution throughout the continent
(Taylor 2004), as grabens, rift systems and mountain ranges determine the flow
of water following gravity causing the formation of large lakes
and pooling of water in lower regions. Additionally, tectonics affect “regional
patterns of atmospheric circulation” (Taylor 2004: 3). Regions of higher
elevation like e.g. horsts or rift shoulders receive generally more
precipitation, while areas in the rain shadow of e.g. mountains experience
lower annual rain fall (Taylor 2004). Comparing fig. 1 and 2 it becomes
clear that areas with a high amount of annual rainfall are not necessarily the regions
with the largest sources of
overland flow and ponding of water e.g. in lakes.
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| Fig 1: Annual precipitation in mm/year (Thornton 2014, 39) |
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| Fig 2: Africa´s Water Towers (UNEP 2012, 3) |
Furthermore, the African continent shows high variability of annual and inter-annual rainfall patterns resulting in remarkable fluctuations of river discharge throughout the year (Conway et.al. 2009). As a result of atmospheric circulations, the climatic conditions in the tropical parts of SSA are dominated by the inter-tropical convergence zone (ITCZ), a dynamic system that moves throughout the year, bringing “distinct rain seasons to latitudes at the southern and northern limits of the ITCZ oscillation” (Taylor 2004: 4), whereas regions in lower latitudes “experience two rainy seasons” (Taylor 2004: 4) (see fig. 3). Thus, lower latitudes receive more rainfall than higher latitudes further north and south. These dynamics result in highly variable river discharge that changes throughout the year. Thus, especially in the northern and southern part of SSA water availability is highly dependent on seasonal changes. Additionally, about 70 to 90 % of the rainfall in east and southern Africa is lost through evapotranspiration (Taylor 2004) and is thus not accessible for use at all.
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| Fig 3: Seasonal Position of the Intertropical Covergence Zone (ITCZ) (Source) |
In a
continent that faces such a remarkable seasonal variability of rainfalls and is
“increasingly affected by recurrent drought” (UNEP 2012: 11) due to climate
change, groundwater is an essential source of freshwater. Africa holds a number
of sedimentary aquifers mainly in the Sahara and Central and Southern Africa as
well as coastal aquifers (UNEP 2012). The largest of these aquifers are located “in the cotinent´s arid and semi-arid
dryland zones” (UNEP 2012: 12). These areas, although often dry, have a huge
potential for water development and may play an important role in securing food
production in the future.
Simultaneously, water accessibility is not only influenced by physical characteristics of
the landscape, but it is also affected by socio-economic and political
implications. Due to population growth water demand is increasing rapidly,
especially in urban areas, where according to the UNEP (2012) population grew by 3.4% (UNEP 2012: 8) between 2005 and
2010. Additionally, demand for water is increasing due to improving living standards
(UNEP 2012). Furthermore, water accessibility is affected by weak
infrastructure especially in rural areas, flawed planning and lack of financial
resources. At the same time poverty limits the population´s ability to
make use of existing structures, such as irrigation, rain-water harvesting and
groundwater exploitation (UNEP 2012).
Water
consumption for farming is especially significant, as for about 90 % of the
rural population agriculture is the main source of income (UNEP 2012).
According to the UNEP (2012), “stimulating economic growth through agriculture
is four times more effective in raising incomes of poor people” (UNEP 2012: 10). Additionally, agriculture is vital to achieve food security. On the
one hand, it makes way for the development and intensification of local food
production, thereby making rural areas attractive for investment and bringing capital
to poor regions (UNEP 2012). On the other hand, it contributes to decrease
undernourishment und famines in large parts of Africa. Thus, agriculture shows
a great potential for ensuring food security and improving people´s living
conditions. However, at the same intensive and ineffective farming may lead to
soil degradation, pollution of drinking water and exploitation of water
resources. As a result of intensification of agriculture, water demand is rising
and puts even more stress on local water shortages. Consequently, effective
management of water resources it is vital to ensure sustainable long-term
development in Africa´s rural regions (Taylor 2004).
To put it
in a nutshell:
Africa´s
water problem is not only complex, but also highly contradictory. In terms of
water accessibility Africa faces “surplus and scarcity, under-development and
overexploitation and challenges and opportunities” (UNEP 2012: 1) at the same
time. Thus, it is important to note, when thinking about issues of
accessibility of drinking water and food production, that Africa is highly
heterogeneous. It does not only show a wide range of geologic, topographic and
climatic differences, but also consists of 55 different countries with
different political and economic systems and a huge diversity of cultural and
ethnical characteristics. Hence, Africa faces very distinct challenges in
different parts of the continent that may vary locally and that require
different approaches to deal with them. In the following blog entries, I will
try to outline some of the major issues and approaches also drawing on both local
examples and integrative approaches on a larger scale.
References
Nice to read that you have embraced some of these apparent contradictions in surplus and scarcity. Which of lacking infrastructure or seasonality in freshwater supply do you see to be the greater challenge to overcome?
ReplyDeleteIn my opinion seasonality is something people can adapt to e.g. with technologies like storing devices or water pumps to pump groundwater, whereas the lack of infrastructure is man-made and clearly disadvantages certain areas often following a political agenda.
ReplyDeleteHowever, one has to admit that it is all about resilience. Thus, lack of infrastructure and seasonality of freshwater are linked, as infrastructure affects the ability of people to adjust to climatic change. Therefore, it is kind of vicious circle: if infrastructure including technology is lacking, to make use of alternative water sources for example, seasonality affects people more, which leaves them with smaller yields and thus less output. This makes it even more difficult to afford technologies, machinery etc. to adapt. But, still I think providing sufficient infrastrucutre is really the key, as access to markets, education and technonogy can empower farmers and make them more resilient to climate change.
A nice example of how this can work, can be seen in this video by the FAO: https://www.youtube.com/watch?v=JJBpeVDAR5w&t=181s