Does existing mixed land development promote the urban spatial composite function? Evidence from Beijing, China

Urban development in China is entering an era of stock space utilisation. Herein, the spatial composite utilisation is a crucial approach to high-quality urban spatial development. Deconstructing the traditional notion of mixed land use indicates that mixed land development driven by the land market may significantly impact urban spatial composite function (USCF). To assess this effect, we analysed the theoretical mechanisms affecting the USCF in a coupled human-land spatial system. Using 296 town street units in Beijing, China for the spatial analysis of geographic big data, we employed an econometric model to examine the spatial composite functional effects of urban mixed land development (UMLD). The results indicated that the USCF strengthened alongside the maturation of the land market, while the intensity effect of the mixed land development was less pronounced. UMLD significantly promoted the spatial composite function, primarily contingent on the effects within the unit itself. Population density and UMLD exhibited a substitutive relationship in their impact on the USCF, and excessively high population density may attenuate the positive marginal effect of UMLD. Through instrumental variable methods and replacement variable estimations, the results were confirmed as robust. Therefore, the reform in the supply and development mechanisms of existing construction land should be deepened to stimulate market-oriented mixed land development and enhance the vitality of sustained urban spatial functional development. •Redevelopment and utilisation of existing stock space are vital•We apply spatio-temporal geographic big data for POI and land transfer•A framework of coupled human-land urban spatial composite function is constructed•We analyse spatial composite function effects of urban mixed land development•A substitution effect between population density and UMLD in affecting USCF exists