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Green Hills, Blue Cities - an Ecosystems Approach to Water Resources Management for African CitiesGreen Hills, Blue Cities - an Ecosystems Approach to Water Resources Management for African Cities
Of the one billion people living on the African continent, about 40 per cent lives in urban areas. Between 1990 and 2010, the total urban population in Africa doubled from 205 million to 400 million, and by 2050, it is expected that this will triple to 1.23 billion. Of the total urban population, 60 per cent is living in slum conditions. In a time of rapid urban growth, Africa is likely to experience some of the most severe impacts of climate change, particularly when in terms of water and food security. This places huge pressures on the growing urban populations as well as the surrounding urban ecosystems on which they depend.
Available online at: http://www.grida.no/publications/rr/blue-cities
Sources of water for domestic use in Port Harcourt Sources of water for domestic use in Port Harcourt
The main source of water in Port Harcourt is boreholes, which account to about 50 per cent of the water sources for domestic use. Many of these boreholes are shallow, making them prone to pollution, and increasing the risk of water-borne diseases.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Slum population in urban Africa Slum population in urban Africa
One of the major challenges of urbanisation in Africa is the rapid expansion of areas of informal settlements. These slum areas tend to lack infrastructure such as pipe-borne water and sewerage, and services such as garbage collection and waste management are often non-existent.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Access to sanitation in urban Africa Access to sanitation in urban Africa
The number of people in Africa with access to improved sanitation, defined as “one that hygienically separates human excreta from human contact” (WHO/UNICEF 2010), has increased over the last two decades. Still, because of the rapid urbanisation, the proportion of the urban population with access to improved sanitation is on the decrease.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Urban growth rate in Africa Urban growth rate in Africa
Africa’s urban centres are currently growing at an annual rate that is the fastest compared to other regions. The urban expansion is expected to continue, with cities like Abuja and Ouagadougou expecting very high growth in the next decade, while Cairo, Africa’s largest city, is projected to see a comparatively lower growth rate.
27 Feb 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Population distribution in Africa Population distribution in Africa
In 1990 there were only 24 cities in Africa with more than one million inhabitants. Today this number has increased to 48 cities, of which Cairo and Lagos are the largest with more than ten million inhabitants each.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Water supply and demand in Nairobi Water supply and demand in Nairobi
The bulk of water supply for Nairobi comes from Thika, Sasumua and Ruiru Dams, as well as the Kikuyu Springs. Over time water supply for the city has failed to meet demand. The current estimated water demand for Nairobi is 650 000 m3/day compared to the production of 482 940 m3/day (WRMA 2010). The difference between production and demand has been widening over time due to population growth, inadequacy of the carrying capacity of the distributio...
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Access to water in urban Africa Access to water in urban Africa
Improved water sources, defined as “one that is protected from outside contamination” (WHO/UNICEF 2010), is essential for ensuring the health of Africa’s urban dwellers. Although an increasing number of people have access to improved water, rapid urban population growth in the African region has equally increased the number of people without proper access.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Urban population trends, Kenya and Nairobi Urban population trends, Kenya and Nairobi
As the total urban population of Kenya continues to grow, the capital of Nairobi still harbours the largest share of the country’s urban population. Between 1948 and 2009, Nairobi’s share of the country’s urban population increased from 5.2 per cent to 32.4 per cent and in 2009 the city had an estimated 3.1 million inhabitants.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Access to sanitation in Yaoundè Access to sanitation in Yaoundè
Proper disposal of sewage is essential for urban water quality, and in Yaoundè the treatment of wastewater, excreta, and sewage can be classified into two categories – individual wastewater systems (septic tanks and latrines) and collective wastewater systems (sewer and treatment plants). About half of the residents of Yaoundè are connected to the sewer system, while the rest depend on either septic tanks, latrines, or a combination of the two.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Historical population trend, Grahamstown 1840-1980 Historical population trend, Grahamstown 1840-1980
While the white population were the majority in the early period of Grahamstown, South Africa, they were outnumbered around 1920. Historically, the non-white population did not pay for water and sanitation services, and this became a problem when this demographic group became the clear majority.
18 Mar 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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