Maintaining all residential areas per current population size is remarkably tricky in a depopulation. As seen in urban shrinkage and perforation, a shift to an appropriate urban scale is necessary. This study focused on workplaces adjacent to residential areas, which we defined as AD-W, to explore the possibility of acquiring centrality for future urban compactness regarding the polycentricity context. In this paper, we used several statistical surveys and analysis of human flow data by GPS. We then identified the characteristics of residential areas and workplaces and considered the residential distribution of people commuting to these workplaces. The current set of AD-W and neighboring NT is not a compact city in terms of job and residential proximity. However, with AD-W taking on the role of the workplace in areas located in the hinterland, it appears that a relatively compact commuting area is being formed within the conurbation rather than commuting from the outer edges of the conurbation to the central urban areas as has been the case in the past. Furthermore, AD-W has the potential to gradually transform itself into one of the core polycentric cities, mainly located in the conurbation periphery in the future.

Urban heat islands (UHIs) are a global phenomenon of concern, especially in megacities such as Bangkok and Thailand. Addressing UHI effects requires an understanding of their connection to urban spatial structures, with urban ventilation playing a crucial role. This study compared the ventilation characteristics of Bangkok's Yaowarat and Ratchadamri central business districts (CBDs). Utilizing 2022 field measurements, spatial analysis, and computational fluid dynamics (CFD) simulations, this study examined the key factors influencing urban ventilation, primarily wind velocity and open space ratio within a 100-meter radius. Each CBD exhibits distinct ventilation characteristics that are attributable to its unique topography. Yaowarat, characterized by compact low-to mid-rise buildings, manifests poorer ventilation than Ratchadamri, characterized by compact high-rise structures complemented by open spaces, which is consistent across both methods. Yaowarat recorded wind velocity (WV) levels below 1 m/s, while Ratchadamri typically registered WV levels exceeding 1 m/s. However, both areas still exhibited suboptimal ventilation and required improvements in WV. This study highlighted the significance of urban climatology in Thailand, raised stakeholder awareness, and emphasized the value of combining field measurements and CFD simulations to inform urban planning decisions for adapting urban ventilation related to UHIs.

This study analyzed the city networks of the three large urban agglomerations in China by focusing on the internal connections of large enterprises based on their site distribution. The study aimed to accomplish three goals: first, to clarify the characteristics of enterprise networks for each urban agglomeration; second, to indicate the functional structure of each urban agglomeration; and third, to identify why each urban agglomeration forms that kind of network structure. The study found that the whole network of the Beijing-Tianjin Hebei urban agglomeration (BTH) has a relatively narrow connection range but strong connection strength, while the whole network of the Yangtze River delta urban agglomeration (YRD) has a wide connection range but weak connection strength. The whole network of the Pearl River Delta urban agglomeration (PRD) also has a wide connection range and weak connection strength, but both are weaker than the YRD. It was also found that BTH has a monocentric functional structure, while YRD has a polycentric functional structure and PRD has a dual-centric functional structure. In addition, corporate ownership, industry type, and establishment time of enterprises can significantly influence the network structures of urban agglomerations. This study found that a high proportion of state-owned enterprises can strengthen the monocentric structure. Also, the existence of the division of labor can strengthen the polycentric structure. Furthermore, the concentration of central cities is emphasized during the early rapid growth period but changes differently later on by urban agglomerations.

In order to create blue-green infrastructure for urban flood control in a form that matches the local ecosystem, we need to understand the demand for ecosystem services that natural spaces provide to local residents, and consider ways to make better use of them. However, public awareness of blue-green infrastructure created by modifying natural spaces has not yet been fully grasped. An Internet questionnaire survey was conducted of residents living in Asahi Ward, Yokohama City, where old rivers have been converted into greenways due to river redevelopment. The conversion tolerance of old rivers to greenways was classified into three types: old river faction, greenway faction, and neutral. In addition to sex and age, there were differences in the conversion tolerance ratio depending on the experience of going down the river and recognition of the old river. As a result of analyzing the consciousness of the functionality of the old river by factor analysis, when the conversion tolerance of the old river was different, the degree of influence of convenience/safety and historicity/naturalness differed. In addition, covariance structure analysis using multi-population simultaneous analysis revealed that the satisfaction level of the greenway was positively influenced by awareness of environmental functionality, while historicity and naturalness were negatively influenced. In addition, analyzing the frequency of co-occurrence of environmental management and utilization desired for greenways and recognition of issues of old rivers revealed that the old river faction is trying to solve problems, such as the deterioration of water quality and lack of people to manage the natural environment, with the restoration of river ecosystems. This type of ecosystem-based problem solving has a different approach from the anthropocentric greenway faction, which expects beautification by improving the pedestrian environment. Therefore, in the future development of greenways, it will be necessary to secure a zone that utilizes the old river channel as a space for environmental adjustment, and an environmentalist community effort to utilize the ecological functions of the original environment will be important.

Population decline has recently become one of the main issues for urban and administrative policies in many cities and regions of the world. Inter-municipal cooperation (IMC) and the municipal merger are expected to be effective measures to maintain various public services efficiently even under conditions of declining population and shrinking capacities, while there are many controversial discussions regarding their possibilities related to political difficulties and transaction costs. This article examines the difference between IMC and mergers on the application of projects to alleviate or adapt to population decline, using, as an example, the Initiative for Residential Self-sustaining Areas (RSAs) which try to enhance voluntary cooperation between local governments in Japan. The result shows that IMC tends to be more acceptable for projects that are expected to achieve mutual benefit represented by mutual usage of public facilities, whereas projects which give partial and uneven benefit are mostly conducted by mergers.

Urban shrinkage has emerged as a global phenomenon in recent decades, attracting increasing attention from scholars since the early 2000s, with broader geographical scope and research topics. However, there is a lack of systematic reviews encompassing the evolution of discourse, shifting focus, and national context comparisons. This research analyzed 98 articles directly related to urban shrinkage studies from both qualitative and quantitative perspectives to provide a comprehensive overview of current research. The results show that research on shrinking cities emerged in the 2000s, and it has received worldwide attention, with significant studies conducted in the United States, Germany, Japan, and China. Most of the studies have been conducted at the city level. The most prevalent topics are the causes of urban shrinkage and response policies. The perception of urban shrinkage shows a change from unacceptance to acceptance, and the coping strategies have been adjusted accordingly. There are two main planning paradigms: growth-oriented planning and shrinkage-adapted planning. While many scholars have advocated for approaches like “smart shrinkage” and “right-sizing,” some studies have questioned their feasibility and effectiveness. Among the specific coping strategies, economic restructuring and addressing vacancy issues are the focus of attention. Additionally, the discourse and focus of research on shrinking cities vary from country to country, and there are also differences in response policies and involved actors. Furthermore, this study identified blind spots in current research for future exploration.