Urban green space has environmental benefits of purifying the air, reducing the heat island effect and providing the social and economic benefits of rest places and social platforms. An integrated and organized green space system is important for fully realizing the positive functions of an urban ecosystem. Previous studies have considered green space supply and demand, but few studies have examined large-scale, diverse and small-scale systems, making it difficult to conduct a comparative study of urban green space accessibility and equity under the same conditions (such as data sources and calculation methods). Using the two-step floating catchment area method, this study evaluates the equity of 254 urban green spaces in China within four ranges of accessibility: 1 km, 2.5 km, 5 km and 10 km. The study also considers urban house price in the research. The results show the following: (1) There are large differences in the accessibility of green space between different cities in China. Within the accessibility threshold of 10 km, the city with the most accessible urban green spaces has an accessibility level that is 27,813 times that of the city with the lowest accessibility. (2) Within the range of walking/cycling, there are significant inequalities in green space access in the 254 cities; the inequality of green space accessibility in most of the studied cities is at the “dangerous” level. (3) The two-step floating catchment area method indicates that the social superiority (high social class) represented by high housing prices is associated with a greater opportunity to access urban green space services. This paper highlights the main problems associated with the accessibility of urban green space in China and proposes targeted development recommendations. These recommendations provide a reference for urban managers to develop effective green space development policies and realize the optimal allocation of urban green space.

This study used global land-use data interpreted from remote sensing images to quantitatively analyze the spatial and temporal changes in global urban expansion over the past 20 years, as well as the source, rate of expansion, and urban growth patterns of newly added urban land (NAUL) around the world. Some main conclusions included the following. (1) Globally, NAUL was mainly derived from agriculture, grassland, and forest. These three types of land use contributed 68.93%, 10.10%, and 9.76%, respectively, to the land sources for NAUL. (2) Eight countries/regions (CRs)—India, Pakistan, Nigeria, Bangladesh, Philippines, Ethiopia, Egypt, and Vietnam—had significant potential for future urban growth and were designated as the “Emerging Urban Growth G8.” Also, Africa will continue to lead global urbanization after Asia. (3) Global urban expansion was still in a typical stage of edge expansion. Urban expansion in Oceania was the most aggregated, whereas in Asia, it was the most diffuse. (4) Apart from African CRs, the urban expansion rate in most CRs was higher than the population urbanization rate, so urbanization does not pose a significant threat to global food security. In addition, for CR with NAUL>1,000 km², the level of economic development had a positive effect compact urban development. This study mapped large-scale urban expansion using unified data, a unified definition of urban boundaries, and over a unified time span.

The study of industrial land transformation effect is of great significance for promoting the sustainable and healthy development of the industrial economy. This paper adopts panel data of 10 provinces in eastern China from 2008 to 2020, constructs an indicator system including five dimensions on the premise of clarifying industrial land transformation and applies the comprehensive evaluation method of gray relational theory to measure its effect. The results show that: 1) overall, industrial land transformation effect in the eastern region shows a good development trend but there are gaps between different provinces, which have been expanding over time in the extreme values. 2) At the provincial level, in terms of industrial land transformation effect, Beijing, Shanghai, Guangdong, and Jiangsu are in the leading positions; Zhejiang, Fujian, and Hebei are in the middle positions; and Tianjin, Hainan and Shandong are slightly behind. 3) At the dimensional level, Industrial land development dimension and industrial land employment dimension generally show a good trend; the spatial pattern of industrial land optimization dimension and environmental pollution control dimension does not change significantly with most provinces at a low level; development conditions support dimension shows a positive spatial trend, indicating that each province attach importance to infrastructure construction and scientific technological progress, creating positive conditions for industrial land transformation. Overall, the results identify whether industrial land in eastern China is being used rationally, which has practical implications for promoting industrial structure upgrading, scientific and technological progress and ecological environment improvement.

The uneven distribution of populations within urban and rural built-up areas restricts balanced regional development. This study employs statistical data from 296 cities in China covering the years 2010, 2015, and 2020 to analyze the coupling coordination relationship of population density in urban and rural built-up land and its influencing factors. The findings reveal the following: (1) Throughout the study period, population density in urban built-up areas (PUL) experienced a slow increase, whereas population density in rural built-up areas (PRL) declined rapidly. (2) Spatially, high levels of coupling coordination in population density between urban and rural built-up areas are primarily concentrated in the southwestern region, particularly in Sichuan, demonstrating a trend of gradual diffusion from the core to the periphery. Overall, a southwest-high to northeast-low pattern emerged. (3) The regression results indicate that economic development, agricultural structure, public services, and urbanization significantly affect the coupling coordination of population densities in urban and rural built-up areas. Among natural conditions, both elevation and temperature show significantly positive effects. This research provides theoretical foundations and policy recommendations for promoting urban-rural integrated development and achieving regional sustainable development.