The view that housing areas in a city develop in sectors along the lines of communication, from the CBD outwards. High-quality areas locate along roads; industrial sectors develop along canals and railways, away from high-quality housing; working-class housing locates near industry. ‘Basic urban pattern such as concentric zone, sectors and multi-nuclei…can be interpreted as “ideal” conditions or basic structure at local scale, and the real pattern could be viewed as a composition of multiple structures in the urbanization process’ (Xu et al. (2007) Landsc. Ecol. 22, 6).

Sector theory