UNEP/GRID-Sioux Falls

Preface and Forward
1 Introduction
2 Human Influences on Africa's Lakes
3 Case Studies of Africa's Changing Lakes
3.2 Images of Change 1
3.2 Images of Change 2
3.2 Images of Change 3
3.2 Images of Change 4
Epilogue and Acknowledgements

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Atlas of Africa's Lakes Launched at World Water Week in Stockholm

Forest Loss, Invasive Species, Land Degradation, Pollution and Inefficient Irrigation Taking Their Toll

Stockholm, August 2006 - The dramatic and in some cases damaging environmental changes sweeping Africa's lakes are brought into sharp focus in a new atlas.

Produced by the United Nations Environment Programme (UNEP), the Africa's Lakes: Atlas of Our Changing Environment compares and contrasts spectacular satellite images of the past few decades with contemporary ones.

It was formally launched in hard copy at World Water Week taking place in Stockholm, Sweden, between 20 and 26 August 2006.

The rapid shrinking of Lake Songor in Ghana, partly as a result of intensive salt production, and the extraordinary changes in the Zambezi River system as a result of the building of the Cahora Basa Dam sit beside more familiar images of the near 90 per cent shrinkage of Lake Chad.

Other impacts, some natural and some human-made and which can only be truly appreciated from space, include the extensive deforestation around Lake Nakuru in Kenya.

Satellite images that document the falling water levels of Lake Victoria are also mapped. Africa's largest freshwater lake is now about a metre lower than it was in the early 1990s.

Achim Steiner, UNEP's Executive Director, said: "Lakes and the natural goods and services they supply to communities, countries and regions are of huge economic significance. In the United States, for example, the value of freshwater resources for their recreational value alone is estimated at $37 billion a year".

"I hope that the images in the Atlas will sound a warning around the world that, if we are to overcome poverty and meet internationally agreed development goals by 2015, the sustainable management of Africa's lakes must be part of the equation. Otherwise we face increasing tensions and instability as rising populations compete for life's most precious of precious resources," he added.

Mr. Steiner's concerns are highlighted in a separate publication, entitled Hydropolitical Vulnerability and Resilience along International Waters in Africa, also on show at World Water Week.

Compiled by UNEP and Oregon State University in the United States, it assesses the strength of legal agreements between countries sharing the continent's major water systems.

The report concludes that, in order to reduce tensions between nations, much more needs to be done to beef up legal agreements and treaties and to avoid instability in the future.

It points to the Volta River basin in West Africa, shared between Benin, Burkina Faso, Cote D'Ivoire, Ghana, Mali and Togo, as being a particular source of concern.

Over the next two decades, population levels are set to double to around 40 million causing a dramatic demand for water.

Meanwhile rainfall and river flows in the region have declined steadily in the past 30 years with this partly linked to higher evaporation rates as a result of climate change.

"Current water use patterns in the Volta Basin have already stretched the available resources almost to their limits and it will be increasingly difficult to satisfy additional demands," says the report.

"With the sustainability of the Volta Basin under threat, there is urgent need for basin states to cooperate more closely to jointly manage the basin's water resources," it adds.

Some Lake Facts and Figures

The precise number of lakes, both natural and human-made (dams and reservoirs), in Africa is unknown. But the WORLDLAKE database puts the number at 677.

Globally there are an estimated 50,000 major natural and 7,500 human-made 'lakes'.

In Africa Uganda with 69 lakes, has the highest number followed by Kenya, 64; Cameroon, 59; Tanzania, 49 and Ethiopia, 46.

Gabon, with just eight lakes has the fewest in Africa, followed by Botswana, 12 and Malawi, 13.

Africa has about 30,000 cubic kilometres of water in its large lakes

The annual freshwater fish catch in Africa is around 1.4 million tonnes of which 14 per cent comes from Egypt.

However the damming of rivers across the continent allied to the disposal of untreated sewage and industrial pollution has reduced the catch particularly in the Nile Delta and Lake Chad.

Wetlands, often associated with lakes and river systems, are important for wildlife, water supplies and filtering of pollutants.

The most important include those in the Okavango Delta, the Sudd in the Upper Nile, Lake Victoria and Chad basins and the floodplains and deltas of the Congo, Niger and Zambezi Rivers.

However, many are being drained as pest control measures or for agriculture. Niger, for example, has lost more than 80 per cent of its freshwater wetlands over the past 20 or so years.

Close to 90 per cent of water in Africa is used in agriculture, of which 40 to 60 per cent is lost to seepage and evaporation, says the Atlas.

Specific Lakes

Lake Songor, a brackish coastal lagoon in Ghana, emerges as one of the most dramatic visual changes in the Atlas. The lake is home to fish and globally threatened turtles, like the Olive Ridley and green turtle, as well as important bird populations.

In December 1990, it appears as a solid blue mass of water some 74 square kilometres in size. But by December 2000, the water body is a pale shadow of its former self.

Intensive salt production and evaporation at the western end, seen as dark blue and turquoise squares, is thought to be largely to blame. Agricultural extraction of water from feeder rivers like the Sege and Zano may be also taking its toll.

Lake Victoria

The lake, with some 30 million people living around it, supports one of the densest and one of the poorest populations in the world. Around 1,200 people per square kilometre live in and around the lake. Average annual income is less than $250 per capita.

An estimated 150,000 square kilometres of land, equal to 25,000 football pitches, have been affected by soil degradation of which 13 per cent has been severely degraded.

The efforts needed to meet the needs of an additional five million people over the next two decades will be immense.

The water level of the lake rose in 1998 as a result of the El NiƱo rains but, over the last 10 years, it has dropped by about a metre according to measurements by the TOPEX/Poseidon satellite.

Invasive water hyacinths have caused havoc to shipping and the fishing industry. However the introduction of a pest to control the weed has had noticeable impact.

Satellite images from 1995 and 2001 show that the green swirls of hyacinth have disappeared from many of the Ugandan bays like Buka, Gobero, Wazimenya and Murchison.

Lake Djoudj

Located 60 km from St Louis in Senegal, this lake is a haven for some three million birds such as Great White Pelicans and the Arabian Bustard. It once was a series of thin lakes surrounded by streams, ponds and back waters.

Satellite images underline how the lake and its surrounding area have been changed dramatically since the building in 1986 of the Diama Dam 23 kilometres from the mouth of the Senegal River.

The sheer volume of water available has now shifted local agriculture from seasonal, flood-based farming, to year round irrigation-based agriculture.

The atlas highlights other dramatic changes linked with dams such as the formation of Lake Cahora Basa on the Zambezi River after the building of a barrage in the 1970s.

The atlas links many ecological and other changes that have occurred since the natural river flow was changed. These include the decline of flood-dependent grasslands, the drying out of mangroves and the fall in water levels on the tributary Shire River which has significantly affected navigation.

The dramatic loss of vegetation and deforestation around Lake Nakuru in Kenya is also vividly seen from space. This may be part of the reason why the lake, according to UNEP experts, declined in area from about 43 kilometres to 40 in 2000.

Satellite images of other key African lakes covered in the atlas include Lake Alaotra in Madagascar; Lake Bin El Ouidane in Morocco; Lake Ichkeul in Tunisia; Lake Kariba in Zambia/Zimbabwe; Lake Nyos in Cameroon; Lake Sibaya in South Africa; Lake St Lucia in South Africa, Lake Tana in Ethiopia and Lake Tonga in Algeria.

Notes to Editors

These publications "Africa's Lakes: Atlas of Our Changing Environment" and "Hydropolitical Vulnerability and Resilience along International Waters Africa" have been prepared under the auspices of the African Ministerial Council on Water (AMCOW), who's Chairperson and President, Mrs. Maria Mutagamba, Minister of State for Water Resources, Uganda, has gladly provided the Foreword.

High resolution images of all of the 'before and after' satellite images can be found at http://na.unep.net/AfricaLakes/Or go to www.unep.org . Copies of this publication are available on order from EarthPrint.com - UNEP's online bookstore at: http://www.earthprint.com

For More Information Please Contact Nick Nuttall, UNEP Spokesperson, Office of the Executive Director, on Tel: 254 20 7623084, Mobile: 254 (0)733 632755 or 41 79 596 5737, e-mail: nick.nuttall@unep.org

Or contact Elisabeth Waechter, UNEP Associate Media Officer, on Tel: 254 20 7623088, Mobile: 254 720 173968, e-mail: elisabeth.waechter@unep.org

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