An innovative greywater treatment system for urban areas ... - SuSanA

3.7.4 URBANISATION
Country population/
km 2
26 Turkey (west) 303
27 South Africa 300
28 Spain north east 297
29 Turkmenistan 224
30 USA south west 179
31 Kazakhstan 69
32 Australia south 43
The urbanisation, as one of the issues to estimate the ideal application of membrane
bioreactor technology, was assessed on the basis of “United Nations map of urban
agglomerations in 2009”, (see Figure 25: Urban agglomerations in 2009 (proportion urban
of the world: 50.1%); Figure 25). In Australia, North America and Scandinavia the main part
of the population lives in urban spaces, but also in France, Libya, Saudi Arabia, Spain and
large parts of South America the main proportion lives in cities.
Figure 25: Urban agglomerations in 2009 (proportion urban of the world: 50.1%); (United Nations,
2010)
To explain urbanisation here, especially the rural-urban migrations as a major source of
urban growth, a push and pull model can be used. Push factors are not only agrarian
overpopulation, but also inappropriate rural ownership structure, inadequate housing, poor
infrastructure, lack of jobs and training opportunities. The pull factors include real or
perceived better working conditions and higher income, education and training opportunities,
especially for the children, the wider range of consumer goods and a less regimented society
and family life. In general, the decision to migrate to an urban area is not only determined by
one factor, but rather a combination of push and pull forces (Bähr, 2008).
Referring to the identified 32 water scarce countries, the investigation gave the following
results of urbanisation rate, as presented in Table 28. The list of countries is sorted in
descending order.
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