4C. Structure:

In terms of a city layout, cities are not always the same though they may appear this way to the untrained eye. There is a spectrum of city structure with two distinct ends that coincide with the distinct types of countries of the world: developed and developing or first and third world. This spectrum is on display in Africa.

As a self contained unit, Johannesburg, South Africa boasts impressive infrastructure. As a metropolitan area, Johannesburg exhibits many smaller cities uniformly surrounding a large central city. Imagine a drop of water landing on a table and droplets splashing away from the impact area. This is what Johannesburg metropolitan area looks like and this is a common dispersion pattern among western cities, especially New World western cities in North America, Australia, and Africa. The same infectious dispersion pattern can also be observed in Northern Africa, in countries close to Europe.

Outside of the extreme north and south of Africa however, cities show random patterns. Most large cities appear as single, large blobs with little to no surrounding city network.


Figure 9: African lights at night (left, colors inverted) and African population density (right). Viewed together, these maps display the difference between cities in the extreme north and south of Africa and central African cities. In Nigeria (central-west), Africa’s most densely populated country, illuminated cities are spread thin and networks are vague. Meanwhile, Johannesburg (the largest collection of lights in Southern Africa) is an example of the organized and potent nature of western cities. While on the population density map greater Johannesburg metropolitan area is a series of unexceptional dots, on the African lights at night map, it is one of the brightest areas of the continent.


Another difference between first and third world cities is the pattern of fading they exhibit. Fading refers to the gradual decline of urban development observed in satellite pictures where lights are brightest (at night) or land is grayest (by day) in the centre and fades outwards. In the image below, Lagos, Nigeria shows some fading on the level of the central city, or blob, but in terms of the metropolitan area, development abruptly ends. This is not the case with western cities like Philadelphia and New York.

Figure 10: Lagos displays little fading and the surrounding city network is very small (also see Figure 1, Sao Paulo).


Figure 11: Philadelphia (left) and New York (right) show extensive fading and city networks. These two large cities are 78 miles (126km) from one another. For Philadelphia and New York, fading is made possible by the network of smaller cities surrounding the center and suburbs, which are a mix of urban and rural forms. As one’s eye moves away from the center of the city, the metropolitan area gradually fades away. It makes sense that fading would not be observed elsewhere in Africa, as suburbs are indicative of a middle class, which most central African nations have yet to establish.


Finally, in this satellite photo of El Paso (USA & Mexico) we see two different sorts of cities in one. The western city (or first-world city) to the north, and the third world city to the south.