10.2.5.3. Flooding
Because of their combination of several natural resources, such as fisheries
and fertile alluvial soils, wetlands and floodplains often are sites of dense
rural settlements as well as urban settlements, such as N'Djamena near
Lake Chad and coastal areas of southern Mozambique. The east Africa floods of
1998 and the Mozambique floods in early 2000 caused considerable damage to property
and infrastructure. The major infrastructure damage was road and rail network
damage. Communications among human settlements in Kenya, Uganda, Rwanda, and
Tanzania were seriously disrupted, impeding movement of goods and persons in
the region (Magadza, 2000). Many refugees could not be reached by land in Somalia,
resulting in significant depletion of their food and medical supplies and leading
to mortalities. Road and rail links to seaports were disrupted. In both instances,
relief operations were hampered by difficulty of access to affected communities.
In Mozambique, the floods of early 2000 caused approximately 2 million people
to be displaced or severely affected; about 600 died (<http://www.reliefweb.int>,
accessed October 10, 2000). By October 2000, the estimated cost of the Mozambique
floods stood at more than US$167 million in terms of emergency aid funds during
the flooding and in immediate activities to rehabilitate the infrastructure
and relocate displaced persons. The impact on the national economy is still
being evaluated but is expected to be significant.
One identifiable adaptive measure against extreme events that are climate related
is a state of preparedness to give adequate warning of imminent danger and deliver
relief. Facilities to broadcast timely information of developing events such
as storms to rural populations remain weak. National disaster plans are available
in some countries, but financial resources to respond to emergencies are lacking.
The ability to convey impacts quickly to the international media is a factor
in the speed and amount of relief. Recent events in Mozambique and other countries
of southern and east Africa will provide useful lessons in dealing with similar
disasters; there is great value in studying these events not only from the physical
point of view—as the Climate Variability and Predictability Program (CLIVAR)
is proposing in a new Africa program; see <http://www.dkrz.de/clivar/hp.html>—but
also from the social point of view.
There is a need for better understanding of the hydrology of river basins to
identify vulnerable areas and plan coping mechanisms. Management of early warning
systems depends on good understanding of the dynamics of flood systems in real
time.
Because river basins sometimes involve more than one state, as in the Somalia
floods, an effective flood management protocol will call for international cooperation.
A regular bulletin of flood development in Ethiopia would have given the coastal
inhabitants of Somalia time to prepare for damage minimization. In the Mozambique
floods of 1996-1997, for example, the trigger was heavy rains in the Shire
River basin. If the Shire and Zambezi Rivers were managed as one basin system,
it would have been possible to alleviate flooding in the Zambezi delta by manipulating
Zambezi river flow, using the flood control capacity of Lakes Kariba and Kabora
Bassa.
A further need in formulating adaptive strategies is more refined regional
climate change scenarios—especially a better understanding of extreme events.
In southern Africa, for example, most of the regional climate change scenarios
are rather ambivalent with regard to precipitation (Hulme, 1996). In the 1998-1999
season, the city of Harare suffered damage to its roads because sewer transport
could not cope with entrained stormwater. If it were accepted that the frequency
of such seasons would increase, future designs of infrastructure amenities would
take cognizance of that prediction.
10.2.5.4. Energy
Threats to energy security from climate change impacts are outlined in Section
10.2.1. Disruption of energy supplies will have ripple effects in the social
fabric through impacts in economic activity. Some adaptation options for the
energy needs of settlements in the African region are in three broad areas:
- Regional cooperation in sharing hydroelectric potential of the continent,
especially that of the Zaire River
- More intensive use of renewable energy, such as solar and wind energy and
biogas
- Efficient use of biomass.
The countries of the southern and central African region (Democratic Republic
of the Congo, Zambia, Zimbabwe, Botswana, South Africa, Mozambique, Namibia)
already are networked on an electric power grid system. Climate change models
to date indicate minimum changes in the hydrology of the Congo basin, whereas
other basins have significant vulnerability to climate change. A regional project
to develop the hydropower potential of the Congo basin could significantly increase
the energy security of the region without resort to GHG-emitting, coal-driven
thermal power plants.
Alternatives to biomass are wind-driven units, either as direct application
of wind force—as in water-pumping windmills—or for generation of electricity,
as in the windmill farms of Denmark. Biogas units, which utilize livestock dung,
have been demonstrated successfully in rural areas of Zimbabwe.
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