What does "urban hierarchy" refer to?

Urban hierarchy refers to a system that ranks cities based on their size, population, and economic dominance. In this context, larger cities typically have more complex economies, a greater variety of services, and a wider range of influence—both economically and culturally—compared to smaller cities. This ranking is significant in understanding how urban areas are interconnected and how resources, people, and economic activities flow between them.

For example, a major city like New York or Tokyo would occupy a top position in this hierarchy due to its size and global influence, while smaller cities might serve more localized functions. This concept helps explain the distribution of services, job opportunities, and economic activity across different urban centers in a region.

The other options do not accurately represent the concept. Urban planning aimed at reducing environmental impact is a different focus that does not reflect the hierarchical nature of cities. A theory on global city growth discusses broader phenomena rather than ranking, and a classification system for rural towns does not relate to urban hierarchy as it specifically pertains to urban areas.