Search

The impact of urban spatial form on infrastructure investment and ecological environment is as important as that of urban social and economic factors. It is of great significance to study the spatial distribution pattern of cities for deciding the direction of urban spatial development. In this paper, a total of 17 indices of urban spatial morphology, including those describing patch area, shape, and degree of urban agglomeration, were selected. Using the correlation, factor analysis, cluster analysis and non-parametric test of the indices, we studied the 146 cities in China. There was a strong correlation between some indicators, and through factor analysis, four main factors, including the “area-based agglomeration,” “adjacency-based agglomeration,” “shape,” and “shape-area,” explained 79.61% of the variance in the data set. Using cluster analysis, the 146 cities could be further divided into five clusters showing significant differences among them. There were strong regional differences in the spatial forms of Chinese cities, especially cities clustered in the Yangtze river delta, Pearl river delta, Shandong peninsula, Sichuan province. At the same time, megacities (populations greater than five million) had a more complex shape and the spatial axis of medium and small cities (populations less than one million) was more obvious. A more complex urban form would be associated with greater investment of infrastructure, and a more compact city would be higher economic resources, and greater development of public transport. From the perspective of resource saving, megacities were faced with the greater challenge of spatial form. The ecological demands of cities are equally important, and how to balance the ecological space e.g. water and green space in cities to obtain a reasonable spatial threshold should be explored in more detail.

The important role of the entity economy, especially manufacturing, has been further highlighted after the outbreak of COVID-19. This study fills a research gap on manufacturing in the Wuhan Metropolitan Area by analyzing the spatio-temporal evolution patterns and characteristics of manufacturing, exploring the major location factors causing spatial reconstruction and comparing the effect intensities of the different factors in the manufacturing sector. From 2003 to 2018, the process of industrial suburbanization in the Wuhan Metropolitan Area continued to strengthen and currently the overall spatial pattern of manufacturing in the Wuhan Metropolitan Area is characterized by spreading in metropolitan areas and aggregation in industrial parks. The results of a spatial metering model showed that the dominant factors affecting the layout of manufacturing included innovation and technical service platforms, industrial parks, the number of large enterprises, living convenience, and air quality. However, the effect intensity of the different location factors varied among industries. The findings may help the government to understand the characteristics of agglomeration and spreading in the manufacturing industry and, in accordance with the dominant factors affecting the location of this industry, rationally develop ideas for adjusting the industrial layout in the post-coronavirus age.

Urban waterlogging caused by rainstorm occurred frequently in many cities of China these years and seriously influenced city safety and residents' daily life. Meanwhile, many remarkable achievements with open data and big data have been applied in urban research, but rare to urban waterlogging research. Taking Xiamen city in China as a case, this study aims to analyze spatial-temporal distribution of waterlogging and assess waterlogging risk of each district in the city. Risk assessment model was built by considering both population and urban public facilities, which acquired from coupling urban internet open data and field investigation. Then we analyzed the government management efficiency through comparison of urban government management plan and waterlogging information from internet. The result indicates that internet open data can be utilized as an effective tool to identify urban waterlogging risk in China, to verify urban waterlogging management efficiency, and to support for urban waterlogging risk prevention and management combining with field investigation.

Regional transportation development (RTD) is an important stressor of urban agglomeration ecosystems. Groundwater recharge potential may be adversely affected when natural soil is replaced by impervious materials. To systematically identify the urban agglomeration ecological risk (UAER) of RTD in the southern Fujian Golden Triangle, water regulation was used as an assessment endpoint, and RTD was considered the stressor. We used the Soil Conservation Service Curve Number method (SCS-CN) to analyze the internal relationship between the assessment endpoint and the stressor factors. Then, a multi-level risk characterization method was used to show the evolutionary process of risk, and to provide a scientific basis for the management of UAER. Based on the current RTD plan, the UAER assessment shows that there is a 0.90 probability of that the risk distribution results will occur by 2030. The intensity of stress from arterial roads on the urban agglomeration ecosystem is greater than that of the railway system. By considering the development of the railway system as a factor in the stress of RTD, this study of UAER assessment differs from past studies of urban ecological risk assessment, since the latter considers only highways. We also propose a systematic method of risk assessment simulation-prediction.