The global overview of population distribution and density is clearly illustrated by the colour contrast between the densely populated and little or non-populated regions of the world. The dry, cold and altitude zones of the inhabited areas are also shown. Any permanent human habitation beyond these limits/zones are only isolated, as it is usually motivated by certain/specific mining or scientific activities. The tropical rainforest is one of the most sparsely populated areas, even though its area has decreased dramatically in recent decades. Rivers and roadways often serve as development lines.
Population Distribution and Urban Communities In 2007, there were a total of 6.625 billion people on Earth. About 4 billion - more than 60 percent of the world's population - lived in Asia, in second to fifth places follow Africa (944 million or 14.2 percent), North and South America (904 million or 13. 7 percent), Europe (733 million or 11.1 percent) and Oceania (35 million or 0.5 percent). Strong contrasts between metropolitan and peripheral areas in large continents and nations are often seen. There are, for example, areas in which a dense settlement is considerably possible at the cold northern border and the southern dry border. The large urban communities of the World can be divided into two groups. Firstly, there are densely populated and highly industrialised regions. This group includes the northeastern U.S., the "window side" of Japan (east coast) and the Rhine area in Europe, continuing its central axis in the direction