Calculating optimal scale of urban green space in Xi'an, China

Abstract

With the acceleration of urbanization in China, urban problems have become increasingly serious, and have led to the concept of the Park City. This concept involves a consideration of the comprehensive value of green space in order to give full play to the maximum benefit of that green space and, thus, realize the sustainable development of the city. Therefore, an exploration of the optimal scale of urban green space will have theoretical and practical significance for the construction of the Park City and the rational allocation of urban land resources. Taking Xi'an as an example, the present paper comprehensively considers the socioeconomic and ecological benefits of urban green space, and calculates its optimal scale. The results indicate that: (i) in terms of the socioeconomic benefits alone, the per capita amount of green area in Xi’an needs to be larger than 11.08 m2, and there is no theoretical optimal size; (ii) in terms of ecological benefits alone, the per capita amount of green area in Xi’an needs to be greater than 22.98 m2; (iii) in terms of the combined socioeconomic and ecological benefits, the per capita amount of green area of Xi’an needs to be greater than 24.89 m2; (iv) the optimal scale for any city is more siginficantly impacted by the ecological effects than by the socioeconomic effects; (v) to satisfy the development and construction needs of various cities, with their individual characteristics, the optimal urban green space scale should be explored according to the target city’s developmental stage and land use situation. The methods and results of the present study are intended to provide a reference for the future construction of Park Cities in China, as well as the planning of green space systems in other cities globally, and to open new prospects for future research.