scholarly journals Spatial Structure Evolution of Urban Agglomerations and Its Driving Factors in Mainland China: From the Monocentric to the Polycentric Dimension

2019 ◽  
Vol 11 (3) ◽  
pp. 610 ◽  
Author(s):  
Feng Lan ◽  
Huili Da ◽  
Haizhen Wen ◽  
Ying Wang

Urban agglomerations (UAs) have become the urbanized “growth poles”, especially against the background of increasing population flow to cities. The spatial structure of UAs has been deemed the essential factor affecting regional function and sustainable development. Although there have been many meaningful studies on spatial structure changes in China, a systematically comparative work of UAs is still absent. Under this context, this paper examines the changing process of spatial structure in 20 Chinese UAs from monocentric to polycentric during the years 1992–2012 by using the night-time light data—an alternative to census data—and explores the major driving forces underlying the evolution. Our empirical results suggest that there is an obvious polycentric tendency of UAs, the spatial distribution pattern of which is not apparent. Panel regression models reveal that the economic level, the population size, the foreign direct investment (FDI), the human capital, and the transport infrastructure play significant positive roles in shaping the polycentric changing process, while the growth of the government expenditure does the opposite. Moreover, transport infrastructure and FDI are positively associated with polycentric spatial structure in mature UAs; on the contrary, they are negatively associated with it in the emerging UAs. Our study results have important policy implications for rapid Chinese urbanization—the policy whereby “China’s future urbanization development model is to limit the agglomeration of large cities while focusing on developing small and medium-sized cities” may be more efficient in mature UAs.

2020 ◽  
Vol 12 (18) ◽  
pp. 7550
Author(s):  
Jiao Li ◽  
Yongsheng Qian ◽  
Junwei Zeng ◽  
Fan Yin ◽  
Leipeng Zhu ◽  
...  

By shortening the transportation time between cities, high-speed rail shortens the spatial distance between cities and exerts a far-reaching influence on urban agglomerations’ spatial structures. In order to explore the influence of high-speed rail on the spatial reconstruction of an urban agglomeration in western China, this paper employs fractal theory to compare and analyze the spatial structure evolution of the Chengdu–Chongqing urban agglomeration in western China before and after the opening of a high-speed railway. The results show that after the completion of the high-speed railway, the intercity accessibility is improved. The Chengdu–Chongqing urban agglomeration’s spatial distribution shows a decreasing density from the central city to the surrounding areas. Furthermore, the urban system presents a trend of an agglomeration distribution. Therefore, strengthening the construction of high-speed rail channels between primary and medium-sized cities, as well as accelerating the construction of intercity railway networks and rapid transportation systems based on high-speed rail cities, would help develop urban agglomerations in western China.


2021 ◽  
Author(s):  
Elena Pupaza ◽  
Joachim Wehner

Transportation and geography scholars link low-cost flights to a new type of hypermobile migration, but the political implications of this development remain poorly understood. We examine patterns of migration and far-right voting in London following the Eastern enlargement of the European Union in 2004 and 2007. We show that the distribution of migrants from this region is linked to pre-existing transport infrastructure providing access to low-cost flights back home. Combining ward-level election and census data with geo-referenced information on bus stops serving relevant airports, our instrumental variable approach addresses immigrant sorting and reveals a large positive effect on changes in support for far-right anti-immigrant parties between the 2004 and 2012 London elections. Our approach expands the methodological toolkit for studying the effects of migration. The findings challenge claims of low-cost airlines “bringing the EU closer together” and have policy implications based on the spatial predictability we uncover.


Author(s):  
Edward Newman ◽  
Eamon Aloyo

Progress in conflict prevention depends upon a better understanding of the underlying circumstances that give rise to violent conflict and mass atrocities, and of the warning signs that a crisis is imminent. While a substantial amount of empirical research on the driving forces of conflict exists, its policy implications must be exploited more effectively, so that the enabling conditions for violence can be addressed before it occurs. Violence prevention involves a range of social, economic, and political factors; the chapter highlights challenges—many of them international—relating to deprivation, inequality, governance, and environmental management. Prevention also requires overcoming a number of acute political obstacles embedded within the values and institutions of global governance. The chapter concludes with a range of proposals for structural conflict prevention and crisis response, as well as the prevention of mass atrocities.


2021 ◽  
Vol 11 (8) ◽  
pp. 3630
Author(s):  
Muhammad Abdullah ◽  
Nazam Ali ◽  
Charitha Dias ◽  
Tiziana Campisi ◽  
Muhammad Ashraf Javid

Public transport use has drastically declined during the COVID-19 pandemic because the virus spreads through close contact with infected people and contaminated surfaces, especially in closed-environments. Evidence suggests that following the necessary safety guidelines can limit the spread of the virus, however, non-compliance to precautionary measures has been reported widely. Ignoring the precautionary measures may lead to quick transmission of the virus since public transport vehicles generally resemble closed-environments. This study explores people’s intentions to use public transport during the COVID-19 pandemic while adhering to precautionary measures. For this purpose, a total of 1516 useable responses were collected through a questionnaire survey conducted in Lahore, Pakistan. Regression models were developed to model the intentions to use public transport during the pandemic, to adhere to the precautionary measures while using public transport during the pandemic, and to use public transport while suffering from COVID-19 disease. The results of this study will help in understanding the intentions of the public transport users during the COVID-19 pandemic. It will also provide insights for policymakers and public transport operators about further necessary actions to promote safe public transport use during the current and any possible future pandemics. As public transport use declined during the pandemic, policy implications for alternative mobility options such as demand-responsive-transport (DRT) are also presented. Considering the study results, a policy interventions framework is proposed to promote the safe use of various public transport modes, particularly in developing regions.


Author(s):  
Raiza M. Beltran ◽  
Ashley C. Schuyler ◽  
Cherie S. Blair ◽  
Jeremy T. Goldbach ◽  
Carl A. Castro ◽  
...  

Abstract Introduction The US Military is experiencing a rise in HIV infections among gay and bisexual men (GBM) serving on active duty, yet little is known about this population’s uptake of pre-exposure prophylaxis (PrEP), an evidence-based intervention for HIV prevention. This mixed methods study examines the facilitators and barriers to PrEP access and uptake among active duty GBM. Methods Active duty GBM were recruited using respondent-driven sampling (2017 and 2018). Participants (n = 93) answered quantitative survey questions on PrEP interest and accessibility. Another set of participants (n = 10) discussed their PrEP experiences in qualitative interviews. We conducted descriptive and bivariate analyses of quantitative data, while qualitative data were analyzed using structural and descriptive coding techniques. Results Approximately 71% of active duty GBM indicated interest in accessing PrEP. A greater proportion of those who disclosed (vs. did not disclose) their sexual orientation to their military doctor discussed (p < 0.001) or accessed (p = 0.017) PrEP. The following qualitative themes emerged: (1) providers’ negative views and knowledge gaps related to PrEP; (2) lack of a systems approach to PrEP access; (3) confidentiality concerns; and (4) reliance on peer networks for PrEP guidance and support. Conclusions Study results indicate that active duty GBM are interested in and want to discuss PrEP with their military doctors, but gaps in providers’ PrEP-related knowledge and skills, as well as mistrust in the military health care system, remain. Policy Implications A system-wide approach that addresses confidentiality concerns and removes procedural barriers to PrEP access is recommended to improve PrEP uptake in this population.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wajid Shakeel Ahmed ◽  
Muhammad Sohaib ◽  
Jamal Maqsood ◽  
Ateeb Siddiqui

Purpose The purpose of this study is to determine if intraday week (IDW) effect of the currencies reflect leverage and asymmetric impact in currencies market. The study data set comprises of intraday patterns of 15 currencies from developed and emerging economies. Design methodology approach The study applies the exponential generalized autoregressive conditional heteroscedasticity (E-GARCH) model technique to observe the IDW leverage and asymmetric effect after introducing hourly dummies variables, namely, IDWmon, IDWwed, IDWfrid and IDWfrid-mon. Findings The study results favor the propositions and confirm that IDW effect do exist in the international forex markets in relation to hourly trading pattern for respective currencies. Mostly, currencies do depreciate on Monday and Wednesday compared to the rest of the days. However, on the last trading day, i.e. Friday currencies observe an appreciation pattern which is for both economies. The results have an evidence of leverage and asymmetric effect confirmed by the E-GARCH model as a result of press releases and influence by micro-factors in the currency markets. Practical implications The study believes to have theoretical connection related to the better understanding of currencies trend for developed and emerging economies, as the IDW effect exists. Moreover, confirmation of both the leverage and asymmetric effect in observed currencies would be able to assist the investors in making rational choices during the trading hours and would confirm considerable profits through profit incentivized strategies. Originality value The study not only add knowledge to the previous study work in relation to the hourly trading pattern of currencies with reference to the IDW effects but also highlights the leverage and asymmetric effect in currencies that will help in formulating future trading strategies particular to emerging economies.


Author(s):  
B. Li ◽  
F. Huang ◽  
S. Chang ◽  
H. Qi ◽  
H. Zhai

Indentifying the spatio-temporal patterns of ecosystem services supply and demand and the driving forces is of great significance to the regional ecological security and sustainable socio-economic development. Due to long term and high-intensity development, the ecological environment in central and southern Liaoning urban agglomerations has been greatly destroyed thereafter has restricted sustainable development in this region. Based on Landsat ETM and OLI images, land use of this urban agglomeration in 2005, 2010 and 2015 was extracted. The integrative index of multiple-ecosystem services (IMES) was used to quantify the supply (IMESs), demand (IMESd) and balance (IMESb) of multiple-ecosystem services, The spatial patterns of ecosystem services and its dynamics for the period of 2005&amp;ndash;2015 were revealed. The multiple regression and stepwise regression analysis were used to explore relationships between ecosystem services and socioeconomic factors. The results showed that the IMESs of the region increased by 2.93&amp;thinsp;%, whereas IMESd dropped 38&amp;thinsp;%. The undersupplied area was reduced to 2. The IMESs and IMESb were mainly negatively correlated with gross domestic product (GDP), population density, foreign investment and industrial output, while GDP per capita and the number of teachers had significant positive impacts on ecosystem services supply. The positive correlation between IMESd and GDP, population density and foreign investment were found. The ecosystem services models were established. Supply and balance of multiple-ecosystem services were positively correlated with population density, but the demand was the opposite. The results can provide some reference value for the coordinately economic and ecological development in the study area.


2021 ◽  
Author(s):  
Yue Huang ◽  
Ruiwen Liao

Abstract The green economy has gained worldwide attention, especially in the urban agglomerations where population and economic activities are highly concentrated. However, what kind of urban agglomeration spatial structure is more conducive to promoting the green economy? No clear conclusions have been made. Here, we study the impact of urban agglomeration spatial structure on the green economy, and also reveal how urban agglomeration spatial structure influences the three subsystems of green economy. We find that: (1) urban agglomeration spatial structural evolution is closely related to green economy, while in the research period, most urban agglomerations are not located in the optimal range of the spatial structure that drives the green economy. (2) Towards polycentric spatial structure is contributive to green economic growth, however, the excessively polycentric could not benefit green economy. (3) The evolution of urban agglomeration spatial structure exerts heterogenous impacts on the three subsystems when green economy is decomposed into economic subsystem, resources subsystem, and environmental subsystem. Towards polycentric is more conducive to the improvement of economic subsystem and resource subsystem, while, the tendency to monocentric drives the environmental subsystem development. (4) Lastly, our conclusions enlighten the urban agglomeration development planning and spatial mode for approaching a better performance in green economy.


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