Towards the Analysis of Urban Livability in China: Spatial-Temporal Changes, Regional Types and Influencing Factors

The increasing drift of urbanization and its impact on urban human settlements are of major concern for China cities. Therefore, demystifying the spatial-temporal patterns, regional types and affecting factors of urban livability in China are beneficial to urban planning and policy making regarding the construction of livable cities. In accordance with its connotation and denotation, this study develops a systematic evaluation and analysis framework for urban livability. Drawing on the panel data of 40 major cities in China from 2005 to 2019, an empirical research was further conducted. The results show that urban livability in China has exhibited a rising trend during the period, but this differs across dimensions. The levels of urban security and environmental health are lower than those of the three other dimensions. Spatially, cities with higher livability are mainly distributed in the first quadrant divided by the Hu Line and Bole-Taipei Line. Cities in the third quadrant are equipped with the lowest livability. In addition, the 40 major cities can be divided into five categories, and obvious differences exist in terms of the geographical distribution, overall livability level and sub-dimensional characteristics of the different types. Furthermore, the results of the System GMM estimator indicate that the overall economic development exerts an inhibiting effect on the improvement of urban livability in present-day China, but this logical effect exhibits obvious heterogeneity in different time periods and diverse city scales. Finally, there are also differences in the influencing direction and degree of specific economic determinants.

Relationship Between Population Urbanization and Urban Sprawl Across Different City Sizes in China

In this study, a coordination model based on the data of urban population and built-up areas from 2006 to 2015 is used to assess the relationship between population urbanization and urban sprawl across 654 cities in Mainland China. For analysis, 654 cities are divided into five categories (small city, medium city, large city, super city and mega city) and the relationship between population urbanization and urban sprawl is divided into four types (rapid growth of population, rapid expansion of land, shrinkage of population and land and coordinated development between population and land). The results show that 60.6% of cities are rapid expansion of land, 18.5% are rapid growth of population, 14.1% are shrinkage of population and land and only 6.9% of cities are coordinated development between population and land. Small, medium, large and super cities were characterized by rapid expansion of land, while mega cities featured rapid growth of population. The size of the cities decreased mainly because of the shrinkage of people and land while it increased because of the rapid expansion of land. The cities with shrinkage of population and land, and rapid growth of population are mostly distributed in the east of the Hu Line.

Haze pollution and urbanization promotion in China: How to understand their spatial interaction?

Can promoting urbanization and controlling haze pollution result in a win-win situation? Based on panel data from 287 prefecture-level cities in China, this paper uses the 3SLS and GS3SLS estimator methods to study the spatial interaction between haze pollution and urbanization. The results show the following: (1) There is a spatial interaction between haze pollution and urbanization. On the whole, haze pollution and urbanization have a typical inverted U-shaped relationship. (2) Haze and urbanization show different relationships in different regions. The haze pollution in the area left of the Hu Line has a linear relationship with urbanization. (3) In addition to haze, urbanization also has a spatial spillover effect. When the haze pollution in the surrounding areas increases, the haze pollution in the area will also increase, but the level of urbanization will increase. When the level of urbanization in the surrounding areas increases, it will promote the level of urbanization in the local area and alleviate the haze pollution in the local area. (4) Tertiary industry, greening, FDI and precipitation can help alleviate haze pollution. FDI and the level of urbanization have a U-shaped relationship. Industry, transportation, population density, economic level and market scale can promote regional urbanization.

Spatio-Temporal Variations of the PM2.5/PM10 Ratios and Its Application to Air Pollution Type Classification in China

Particulate Matter (PM) is an important indicator of the degree of air pollution. The PM type and the ratio of coarse and fine PM particles determine the ability to affect human health and atmospheric processes. Using the observation data across the country from 2015 to 2018, this study investigates the distribution and proportion of PM2.5 and PM10 at different temporal and spatial scales in mainland China; clarifies the PM2.5, PM10 and PM2.5/PM10 ratios interrelation; and classifies the dust, mixed, and anthropogenic type aerosol. It shows that the annual average concentration of PM2.5 and PM10 decreased by 10.55 and 8.78 μg m−3 in 4 years. PM2.5, PM10, and PM2.5/PM10 ratios show obvious while different seasonal variations. PM2.5 is high in winter and low in summer, while PM10 is high in winter and spring, and low in summer and autumn. Differently, the PM2.5/PM10 ratios are the highest in winter, and the lowest in spring. PM2.5/PM10 ratios show strong independence on PM2.5 and PM10, implying that it can provide extra information about the aerosol pollution such as aerosol type. A classification method about air pollution types is then further proposed based on probability distribution function (PDF) morphology of PM2.5/PM10 ratios. The results show that dust type mainly lies in the west of Hu-Line, mixed type pollution distributes near Hu-Line, and the anthropogenic type dominates over North China Plain and cities in southern China. The results provide insights into China’s future clean air policy making and environmental research.

Hierarchical Characteristics and Proximity Mechanism of Intercity Innovation Networks: A Case of 290 Cities in China

The formation mechanism of innovation networks is one of the core issues in the current research of innovation networks, and proximity plays an important role in the formation and development of innovation networks; however, which proximity is more important and how different proximities interact remain to be further researched. This study conducts a social network analysis and adopts a spatial interaction model to examine innovation networks among 290 Chinese cities. The results reveal that, first, the hierarchical characteristics of Chinese cities’ innovation networks reflect a core periphery structure and the spatial patterns of large dispersion and small agglomeration. Further, bound by the Hu line, the hierarchy is high in the east and low in the west. Second, geographical, institutional, and cognitive proximities positively affect Chinese cities’ innovation networking. Cognitive proximity, particularly, has the highest impact. Geographical proximity reinforces the effect of institutional proximity, and thus, their interactions are complementary.

Could pollution levels, characteristics, sources of PAHs in atmospheric particulate matter break the Hu line?

Were the pollution levels, characteristics and sources of PAHs related to the population and GDP on both sides of the Hu line? What was the relationship between them? The study summarizes and discusses available data for PAHs in atmospheric particulate matter (PM) from 93 above prefecture-level cities in China in 2000-2019. The results suggested that the concentration of PAHs in PM varied with 7 regions of China in descending order: Northeast (NE) > North China (NC) > Northwest (NW) > South China (SC) > Southwest (SE) > Central China (CC) > South China Sea (SCS). Meanwhile, the mean value of carcinogenic PAHs, non-carcinogenic PAHs, PAHs derived from the burning of organic matter, low molecular weight PAHs, medium molecular weight PAHs, and high molecular weight PAHs in 16 priority PAHs was 53.5%, 46.5%, 80.0%, 16.9%, 45.2%, 37.9%, respectively. Moreover, from NW to NC, the content and pollution of PAHs increased with the increase of population and gross domestic product (GDP). From CC to SW and NC, the content and pollution of PAHs increased with the increase of population and the decrease of GDP. From SW to NW and CC to SC, the content and pollution of PAHs increased with the decrease in population and GDP. In part, PAHs pollution, characteristics and sources of atmospheric PM in Chinese cities broke the Hu line of population and GDP. Therefore, these require the promotion of comprehensive measures that will reduce pollution and sources of PAHs in heavily polluted areas.