An integrated model of urban spatial structure: Insights from the distribution of floor area ratio in a Chinese city

• An integrated city model is developed to depict the urban spatial structure of multi-center cities.
• FAR and GWR are used to reveal the complex and non-static nature of the urban spatial structure.
• Influencing areas and uneven spatial effects of the city centers are investigated.
• Advantages of the integrated model over monocentric and polycentric ones are addressed.

The monocentric city model has been challenged for its predictive power in urban spatial structure as multiple centers rise from the spatial expansion and functional diversification of modern cities. To overcome the deficiency of the model in explaining contemporary cities, this study takes Haikou City in China as an empirical case to develop an integrated city model that depicts the urban spatial structure by combining multiple monocentric city models, the basic unit in analyzing an urban space. The applicability of this integrated city model in Haikou is also examined in return by using the measure of floor area ratio and the method of geographical weighted regression. Results show that the traditional spatial structure of Haikou as a provincial capital where production activities are concentrated in the city center has been challenged by the emerging tourism function along the sea coast over the past decades. Compared with the long-existing monocentric “city” model around the city center that exerts a strong, asymmetrical, and unevenly distributed marginal effect on the urban space, the newly developed monocentric “city” model along the coast has a weak, one-sided, and evenly distributed marginal impact on its urban spatial structure. Therefore, the current spatial structure of Haikou City can be depicted by an integrated city model composed of two monocentric “city” models based on different “centers” with distinct urban functions. In this sense, this integrated city model developed on the monocentric city model will be inclusive and extendable to the analysis of the dynamic spatial structure of a multi-center city.