Climate Change 2001:
Working Group II: Impacts, Adaptation and Vulnerability
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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:

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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