Why some areas of the world are densely populated and others are sparsely populated. Extracts from this document... Introduction. Why some areas of the world are densely populated and others are sparsely populated.The worlds population within the last 250years, has gone from 675 million in 1750.Where now the population is at least 6 billion. But the population is not spread over the world evenly.hy some areas of the world are densely populated and others are sparsely populated. Extracts from this document... Introduction. Why some areas of the world are densely populated and others are sparsely populated.