Urbanization and Settlement Patterns

Urbanization is the growing share of a population living in cities rather than rural areas, and it is one of the biggest shifts in human history -- more than half of the world's people now live in urban areas, a milestone crossed only in the twenty-first century. Urbanization is driven largely by the same push and pull factors that drive rural-to-urban migration: limited farm income pushes people off the land, while city jobs, schools, and services pull them in.

A megacity is an urban area with more than ten million people -- Tokyo, Delhi, Shanghai, Sao Paulo, and Mexico City are among the world's largest. In many rapidly urbanizing developing countries, cities have grown faster than housing, water systems, and roads can keep up, producing large informal settlements (sometimes called slums, or in Brazil, favelas) where residents build housing without formal legal title or planned infrastructure. Geographers also describe settlement patterns by shape: dispersed settlements spread housing out widely, common in farming regions where each family needs land; clustered (or nucleated) settlements group tightly around a shared resource, crossroads, or defensive point; and linear settlements string out along a road, river, or coastline.