Why are cities established where they are? How do local economies and politics influence patterns of human settlement and development at such a grand scale that these patterns can be identified from space? This photograph of Johannesburg, South Africa, taken from the International Space Station illustrates the human geography of the region.
In this case, the cityscape of Johannesburg is the most difficult pattern to discern. The center of Johannesburg is the fine-grained pattern (created by shadows cast from the high rise buildings in the city) in the center of this mosaic. On the southern fringe of Johannesburg is a line of light colored, angular patches stretching across the scene. These patches are the great “mine dumps” (an example is arrowed), the crushed rock that remains after gold extraction from numerous gold mines. These are the mines that underpinned the South African economy for decades, and their dumps, or tailing piles, are the visuals that orbiting crews see when they overfly Johannesburg and neighboring cities, delineating the east-west outcrop of the gold-rich rock strata discovered in 1886. Some mine dumps are so large that an outdoor movie theater was located on one of them. Neighboring industrial cities are nestled among the mine dumps as far as the edges of the photograph. Older mine dumps nearer the Johannesburg city center have disappeared from view in the last 25 years, having been re-mined for the gold that remained within them.
The green zone (top right) is the leafy northern suburbs, where hundreds of square miles of grassland have been progressively forested since Johannesburg was founded in 1886. Small light patches within the tree-rich zone are satellite businesses and shopping centers, typical of any major western city. By contrast, a major ghetto (established by the former South African government) typical of developing-world urban migration, appears as the grey zone lower left (the famous Soweto Township). Soweto appears largely treeless except for protected valley bottoms.