Changes in the population distribution and transport network of Saint Petersburg

The authors explores the interdependence between demographic changes and transport network centrality, using Saint Petersburg as an example. The article describes the demographic data for the period 2002-2015 and the transportation network data of 2006. The authors employ several methods of demographic research; they identified the centre of gravity of the population, produce the standard deviational ellipsis and use the kernel density estimation. The street network centrality of Saint Petersburg was analyzed using the Multiple Centrality Assessment Model (MCA) and the Urban Network Analysis Tool for ArcGIS. The analysis of the population distribution in Saint Petersburg shows that each area of the city has seen their population grow over the last thirteen years. However, it is the population of suburban areas that increased the most. The core area of the city has the tendency of outward diffusion, and the population gravity centre has been moving northwards. Spatial characteristics of the population growth, changes in the population gravity centre, the standard deviational ellipse and characteristics of the street network centrality show that Saint Petersburg is at the final stage of urbanization and its development pattern is similar to that of other major cities

Analyzing the Structure of Residence–Leisure Network in Shenyang City

Leisure is an important part of the daily activities of urban residents. A relatively dense flow of people will be generated between residential areas and supermarkets, as well as between residential areas and highly popular park facilities. These flows of people can reflect the characteristics of residents’ leisure activities and the spatial characteristics of urban residence–leisure functions, as opposed to static leisure facilities and places; it is a new perspective for the study of urban spatial structure. Network studies on the relationship between residential and leisure functions within cities are rarely seen. In this study, from the flow space perspective, based on the questionnaire data, points of interest data, and mobile phone signaling data, the actual leisure travel flows of residents with different travel purposes can be identified, including residence–shopping leisure flows and residence–park leisure flows, and the corresponding urban networks can be constructed from them. With the help of complex network analysis, this paper discusses different types of residence–leisure network structures and their influencing factors in terms of network characteristics, node strength, and QAP analysis. It deepens the understanding of the urban spatial structure and provides the theoretical basis and technical support for urban structure analysis, urban layout optimization, and urban planning and management. The results show that: ① Both residence–shopping leisure and residence–park leisure networks have the small-world characteristics and scale-free properties of complex networks. ② The characteristics of the nodes of the residence–leisure network for different leisure travel purposes indicate that residents go more to Taiyuan Street and the New North Station business circle for shopping activities, and the parks that attract residents to go out for walks are concentrated in the central part of the city. ③ Different types of network structures have a strong correlation with the number of residential functions and leisure facilities but have a weak correlation with the difference in the number of inhabitants and leisure travel distance. This study enriches the research cases of the urban residence–leisure network structure to a certain extent. Shenyang City has the same background of rapid expansion as other large cities in China, and this study has an important role in planning and inspiration for solving urban diseases and achieving the orderly and rational development of large cities

Structural Efficiency and Robustness Evolution of the US Air Cargo Network from 1990 to 2019

As the US air cargo network (USACN) becomes a crucial part of the economy, it is pivotal to understand the structural evolution of the network and how it would be affected by unexpected events. We investigated the network structure, efficiency, and robustness of the USACN from 1990 to 2019 due to targeted attacks based on complex network theory from a dynamic and spatiotemporal perspective. Our results suggest that the USACN has enhanced robustness. Moreover, we find that attacks based on betweenness centrality are the most effective way to cause a collapse compared with attacks based on degree and closeness centrality. In addition, airports of the USACN have formed an increasing number of communities with geographical ties, and airports in the noncontiguous regions are more vulnerable than other communities in the lower 48 states. Further, we discover that the average path lengths have increased, and the overall efficiency has decreased from 0.7 to 0.4 due to the dependency of the hub-and-spoke structure. This paper complements previous studies on the dynamic structure evolution of air cargo networks through the lens of complex network theory with spatial-temporal data

How to Design Greenway on Urban Land Utilization: Linking Place Preference, Perceived Health Benefit, and Environmental Perception

The rapid urbanization and over-crowded urban environment have caused a serious public health crisis. Numerous studies have found that public green spaces can benefit human health and well-being. Therefore, a short supply or an inappropriate planning of public green spaces would exaggerate the health crisis. For all these reasons, how to create health-promoting greenways in urban areas becomes a critical and pressing challenge for urban sustainability. To address this challenge, we conducted a photograph-survey study of a greenway to examine the relationship between place preference, perceived health benefit, and environmental perception. Through a set of linear regression analysis, we found that: place preference is significantly and positively associated with six specific perceptions, including relaxation when walking alone, cheering of one’s mood, being away from daily life, traffic safety, recovery from stress, and mental fascination. Furthermore, we identified the important environmental perception elements that have significant positive or negative associations with each identified perception; these were carefully planned. This study is an initial effort to examine a critical urban land-use issue: appropriate planning of greenways in the city to promote public health and well-being. The research findings provide strong and clear guidance on planning strategies for urban greenways and shed light on future studies

Urban Human-Land Spatial Mismatch Analysis from a Source-Sink Perspective with ICT Support

The development management of the city constantly pursues sustainable development of human-land matching. Under the new research framework, this study discusses the urban human-land relationship from the perspective of the source-sink of daily population mobility, making up for the lack of a static research perspective in the past. The spatial relationship between population source-sink and land use intensity was studied by bivariate Moran’s I and multivariate correspondence analysis. The results show that there is a significant spatial correlation between urban population source-sink and land use intensity, which is obviously affected by urban circles and land use types, and these laws are cyclical day after day. The urban fringe becomes the main place where spatial mismatch occurs. Currently, the spatial mismatch of cities in northeast China, represented by Shenyang, is dominated by the high intensity of land use and low flow of the population. The key to solving the problem is to curb the high-density urban sprawl. The research results improve the integrity and accuracy of urban human-land spatial mismatch analysis and provide support for formulating more specific urban land use policies

Creating a Healthy Environment for Elderly People in Urban Public Activity Space

According to statistics, the global, population aging problem is severe and growing rapidly. The aging problem is most obvious in some European countries, and most of them are developed countries, such as Japan, Italy, Germany, France, etc. The current internal and external environments of parks in China are complex. The inefficient utilization of space in urban parks is a prominent problem. The design of public spaces that only considers the visual experience is incomplete. Based on the optimization of urban park space planning principle, this study examined a new measure of the acoustic environment in elderly public activity space and designed a new elderly healthy urban park environment. Methods: Using the main parks in Shenyang (Zhongshan Park, Nanhu Park, Youth Park, and Labor park) as the study sites, this study analyzed problems in the acoustic environmental data through on-site inspection, questionnaire survey, and physical data collection. By using general linear regression and multiple regression methods, this study analyzed the impacts of plant density, site elevation, structure enclosure, functional mixing degree on the acoustic environment, and elderly population activities. Based on the acoustic environment, we propose improvements and construction ideas, as well as technical methods, for urban elderly public activity space planning. The utility of the “elderly public activity space planning principle” was also considered. Results: Elderly activity space in urban parks was affected by three main factors—plant density, degree of structural enclosure, and function mixing degree. These factors should be optimized to construct healthy acoustic environments and attract different types of people. Discussion: Compared to past studies, the new influencing factors of the planning principle for elderly public activity space found in this study, would benefit the urban park environment for the elderly and support sustainable development of cities. Conclusions: This study proposes three optimizations to the elderly urban park space planning principle and builds four healthy models of elderly urban space activity

Landscape-Based Assessment of Urban Resilience and Its Evolution: A Case Study of the Central City of Shenyang

Urban resilience is increasingly considered a useful approach to accommodate uncertainties while achieving sustainability in urban systems, especially in the context of rapid urbanization and global environmental change. However, current research on the quantitative assessment of urban resilience is limited. This study introduces four proxies of urban resilience, i.e., diversity, connectivity, decentralization, and self-sufficiency, and the perspective of the urban landscape for the measurement of urban resilience and further guidance on planning practices by establishing connections between resilience potential and landscape characteristics. Using multi-source data and employing landscape-based analysis methods, urban resilience is investigated from 1995 to 2015 in the central city of Shenyang. The results indicate that the composition and configuration of the urban landscape changed significantly during this period, which had a great influence on urban resilience. The temporal and spatial evolution of urban resilience showed obviously directional preferences and an evident distance effect. Overall, the resilience level increased slightly, while the internal differences experienced a declining trend. The four characteristics can be deployed as practical principles to shape urban resilience. The adjustment and trade-offs of these aspects to enhance responsive structures and simultaneously maintain sustainable ecosystem services can be effective ways to realize long-term resilience

FedEx and UPS Network Structure and Accessibility Analysis Based on Complex Network Theory

With the expansion of the global air cargo transport system, the operating structure of air cargo has become increasingly separate from passenger counterpart, forming an independent organization model. Despite the Chinese air cargo capacity has grown exponentially in the past, its network is still in its infancy. FedEx and UPS have well-established air cargo networks and have operated effectively on both international and domestic scale; thus, understanding the structure and evolution of their air cargo networks is of a high reference value. In conjunction with the division of US regions from the United States Geological Survey (USGS), this paper refers to FedEx and UPS as FEPS and analyzes its topological structure, complexity properties, and air cargo accessibility by using social network analysis (SNA) and accessibility evaluation methods. The results suggest that (1) the structure of the FEPS air cargo network is in the highly developed states and has the typical “small-world” and “scale-free” network characteristics; (2) the degree centrality values for the nodes in the FEPS network suggest that the network complexity has increased; (3) airports in Memphis (MEM), Louisville (SDF), Indianapolis (IDN), and Ontario (ONT) are the major hubs with both high centrality values and air cargo accessibility; and (4) the FEPS network presents a unique hub-and-spoke structure compared with the passenger counterpart

Improving Urban Resilience through Green Infrastructure: An Integrated Approach for Connectivity Conservation in the Central City of Shenyang, China

Green infrastructure (GI) as an operational physical framework is being increasingly recognized as the most cost-effective way to mitigate and adapt to social-ecological challenges through multifunctional ecosystem services. Conserving the connectivity of GI is conducive to maintaining biodiversity and facilitating ecological processes, which contributes to promote urban resilience and implies that urban governance has made a conscious effort to prepare for uncertainties. Though important, there are few studies on operating GI practically to navigate urban resilience. Based on interdisciplinary knowledge and multiple techniques, this study provides an integrated approach, in which relationships between GI connectivity, resilience potential, and conservation strategies are better addressed. The results indicate that significant changes have taken place in terms of the composition, layout, and connectivity of GI in the central city of Shenyang between 1995 and 2015. Through pinch point identification and barrier detection, conservation strategies by protecting key structures, eliminating local barriers, and implementing differentiated measures according to land use types are therefore proposed. The strategies may be helpful for future policy formulation, planning, and management by rehabilitating a GI network to increase urban social and ecological resilience in the study area and other similar megacities. This integrated approach based on a generic process of geometric analysis has general applicability to make interdisciplinary contributions toward urban resilience

Strategic Cross-Border Water Pollution in Songliao Basin

This paper studies the two-fold impacts of environment regulation related to local officer promotion and water quality assessment of cross-border sections within the framework of the 11th Five-Year Plan. We employ the difference-in-difference (DID) and difference-in-difference-in-difference (DDD) models to a unique dataset on water polluting activities in Songliao Basin counties from 2003 to 2009. Empirical results show that on one hand, regulation and water pollution are negatively correlated, the stricter the regulation is, the less water pollution happens. On the other hand, as no explicit accountability and synergetic governance system were set up by the 11th Five-Year Plan, prefecture-level municipal governments tend to exert the least enforcement efforts in the most downstream counties. We find the evidence of strategic water polluting that the overall output value, new entry into and old business water polluting industries are significantly higher in the most downstream county of a prefecture-level city, relative to other similar counties