The accurate estimation of the impact of urban form on CO₂ emissions is essential for the proposal of effective low-carbon spatial planning strategies. However, few studies have focused on the relationship between urban form and CO₂ emissions in small and medium-sized cities, and it is especially unclear whether the relationship varies across cities with different socioeconomic characteristics. This study took 132 small and medium-sized cities in the Yangtze River Delta in China to explore how urban form affects CO₂ emissions, considering the socioeconomic factors of industrial structure, population density, and economic development level. First, nighttime light data (DMSP-OLS and NPP-VIIRS) and provincial energy data were used to calculate CO₂ emissions. Second, four landscape metrics were used to quantify the compactness and complexity of the urban form based on Chinese urban land-use data. Finally, panel data models were established to analyze whether and how different socioeconomic factors impacted the relationship between urban form and CO₂ emissions. The results showed that the three socioeconomic factors mentioned above all had obvious influences on the relationship between urban form and per capita CO₂ emissions in small and medium-sized cities. The effect of compactness on per-capita CO₂ emissions increased with a rise in the proportion of the tertiary industry, population density, and per-capita GDP. However, compactness shows no effects on per-capita CO₂ emissions in industrial cities and low-development-level cities. The effect of complexity on per-capita CO₂ emissions only increased with the rise in population density. The results may support decision-makers in small and medium-sized cities to propose accurate, comprehensive, and differentiated plans for CO₂ emission control and reduction.

The elderly population have a high incidence of cardiovascular disease and are the main users of green spaces, such as city parks. Creating supportive green spaces for exercise for the elderly is of great significance to promote their cardiovascular health. The winter cities have a severely cold climate and high incidence of cardiovascular disease, while the elderly, especially those with cardiovascular disease, face more challenges when participating in exercise in the green spaces. In the context of the winter cities, the kinds of exercise the elderly participate in are more conducive to their cardiovascular health, and determining the factors of the green spaces that are supportive for exercise for cardiovascular health in the winter are of particular interest. Taking Harbin, a typical winter city in China, as an example, this study aims to identify the exercise characteristics of elderly residents in the green spaces in winter, to link them with the principles and contents of exercise prescription for cardiovascular health, to identify the deficient factors of the green spaces in supporting exercise for cardiovascular health, and to put forward optimization design implications. Mixed qualitative methods including interviews, a questionnaire, and field observation were used to identify special behavioral characteristics and spatial factors involving winter exercise in the green spaces among the elderly. The results showed that: (1) about 42.4% of the participants had a gap with the principles of exercise prescription for cardiovascular health. Their exercise items were generally consistent with the principle of low-intensity exercise, but some of them had the problems regarding early exercise time and insufficient exercise duration and frequency. (2) Insufficient supportive factors of the green spaces mainly included facilities allocation, comfort, safety, accessibility, and air quality. Facilities allocation involved walking paths, rehabilitation facilities, auxiliary facilities, and guidance facilities; comfort involved sunlight conditions of the exercise areas; safety involved slippery roads and sites with ice and snow and medical accidents; accessibility involved the proximity, the safety of connecting roads, and the movement of the elderly; air quality involved the planting of evergreen trees. Accordingly, the design implications were given in order to bridge the supportive gap of the green spaces for exercise for cardiovascular health in the elderly population.

The multi planning contradictions and maladjustment of spatial management that evolved from an unbalanced development are becoming increasingly serious in China; therefore, it is imperative to know how to coordinate spatial planning. The scientific division of spatial unit attributes and the identification of ecological–agricultural production–living spaces (EPLs) have become the key scientific problems of this period. The existing urban structure zoning model, the urban growth boundary model, and the function-oriented zoning model show three main shortcomings: the difficult data acquisition and the large limitation of the application because of their high requirements of the related parameters, strong subjective weight setting, and lack of comprehensive zoning in the EPLs practice. This paper builds a quantitative and easily operated model for the spatial zoning of municipal administrative areas (MAA) based on the existing spatial equilibrium model for regional development. Three representative cities in China were modeled empirically with this model and the results were compared with those obtained by the existing models. We investigated the image consistency of this model to the three existing models where the Kappa values were 85.9%, 88.2%, and 85.2%, respectively, with an average of 86.4%. This showed that the model could reduce the data limitation and expand the scope of the application while ensuring the accuracy of the model’s analysis results. Meanwhile, the EPLs zoning was clearer, which made the spatial plan coordination more efficient and scientific. Overall, this model could not only solve the problem of the EPLs zoning and spatial plan coordination in MAA, but also guide urban land use planning from two dimensions of space and time and effectively promote the coordination and sustainable development of spatial planning.

The overall planning of urban and rural areas is the focus of municipal administrative area (MAA) planning in the process of economic globalization, and village-town system planning is the key to the overall planning of urban and rural areas. Based on the theory of spatial equilibrium and economic logic, an objective municipal administrative area spatial zoning model (M-MSZ) was constructed in our previous study. The M-MSZ model can provide guidance in the planning of a village-town system. This paper takes a city in the south of Heilongjiang Province in China as an example and compares the M-MSZ model with six traditional MAA spatial zoning models (the urban growth boundary model, land use planning model, spatial governance zoning model, major MAA location, layout and planning model, development timing-order and zoning model, and scale and function zoning model) to verify the value and superiority of the M-MSZ model in the planning of a village-town system. The consistency Kappa values were 78.2%, 83.3%, 82.3%, 79.8%, 75.7%, and 83.9%, respectively, which means that the M-MSZ model was highly consistent with those comparison models. Meanwhile, the regression coefficient R² is higher than that of the traditional spatial zoning models, which means that the objectivity of the M-MSZ model is higher than that of traditional models. The superiority of the M-MSZ model over the traditional MAA spatial zoning model lies not only in its capacity to grasp the core content of village-town system planning, but also in its capacity to unify the decentralized urban system planning models that are used for village-town system planning, while realizing the objectivity of a weight assignment. Its unified model structure, objective integrated model system, and high accuracy make the M-MSZ model capable of solving the key problems associated with village-town system planning, with many advantages, such as easy operation, high efficiency, good inheritance, low cost, and greater objectivity, detail, and accuracy. In addition, it can provide a reference for the development model of a MAA village-town system.