Hasil untuk "Urbanization. City and country"

L. Xu, Meiting Fan, Lili Yang et al.

Abstract Green innovation has been positioned as an effective way to balance economic development and environmental governance. However, the impact of green innovation (i.e., innovation relating to the environmentally sound technologies (ESTs)) on carbon emission performance in a large developing country, such as China, has been paid little attention. This paper investigates the impact of green innovation on carbon emission performance based on a panel data set covering 218 prefecture-level cities in China from 2007 to 2013. First, we examine whether heterogeneous green innovations have a synergistic effect on carbon emission performance using the two-way fixed effect model, instrumental variable method, and spatial econometric model. Moreover, using a causal mediation effect model, we identify four kinds of potential transmission channels of green innovation affecting carbon emission performance: energy consumption structure effect, industrial structure effect, urbanization effect, and foreign direct investment (FDI) effect. The results indicate a positive effect of green innovation and its sub-categories on carbon emission performance in China. However, a noteworthy phenomenon is that direct carbon emission-reduction innovation and green administrative innovation have a weaker effect on carbon emission performance than other kinds of green innovations. In addition, the positive effect has an evident heterogeneity in different kinds of cities. To be specific, green innovation has an evident positive impact on carbon emission performance in key cities for environmental protection, resource-based cities, non-resource-based cities, and central cities. Meanwhile, a “snowball” effect and a symbiotic effect of carbon emission performance exist in local cities and between cities, respectively. Finally, we find that green innovation significantly decreases and increases carbon emission performance through industrial structure effect and FDI effect, respectively.

Mathias Lerch, Wenxiu Du, Dorothee Beckendorff

Our understanding of the patterns of internal migration that underlie the fast urbanization in developing countries is mainly based on theory and country case studies. We test the hypothesis of a mobility transition from a comparative perspective by analyzing the evolution of different types of internal migration across the settlement hierarchy over the course of urbanization. We rely on repeated population censuses from 41 developing countries, consistent remote‐sensing definitions of urban agglomerations, and statistical modeling to integrate and ensure the comparison of the international set of migration estimates. Results confirm a declining inter‐rural migration at the beginning of urbanization alongside a rising rural exodus, which diffuses down the settlement hierarchy alongside a progressive shift from proximity to long‐distance migration. Relative to the largest city, the attractiveness of secondary urban destinations persists and tends to rise in late stages of urbanization. However, inter‐urban migration played a major role in the initiation of the mobility transition but later declined. Large shares of urban‐ward migration are diverted to the rural hinterland of cities, and the rural exodus does not level off. We provide potential explanations for these deviations from the mobility transition hypothesis, propose theoretical amendments, and discuss the implications of our findings.

Françoise Okah Efogo, Paul Awoa Awoa

This article focuses on the challenges that uncertainty poses to countries in global and regional value chains. In this perspective, it focuses specifically on African countries and enriches the results with a comparative approach. Indeed, using a gravity model for 49 African countries and all their trading partners from 1990 to 2019, the paper proposes a comparative analysis of the effects of uncertainty on global trade in value chains and on trade in value chains within Africa. The robustness of the results shows that domestic uncertainty can drive the expansion of intra-African trade in value chains, while uncertainty in the partner country hinders the flourishing of trade relationships within a value chain.

Chiara Amato, Mario Cerasoli

The article explores the revitalization of Italy's "inner areas" - —fragile territories facing challenges such as depopulation, abandonment, and a lack of essential services, primarily due to limited mobility. The enhancement of secondary and disused railways is proposed as a tool for territorial rebalancing, to be achieved through multilevel governance that integrates spatial planning, interinstitutional cooperation, and the strategic allocation of financial and economic resources. This approach aims to move beyond sectoral perspectives on infrastructure networks.  The Axis Contract is introduced as an integrated framework linking urban planning and mobility, centered on the right to mobility and the empowerment of local communities.  The article is structured into three parts: the first examines the relationship between territory, mobility, and infrastructure policies; the second analyzes the French Contrat d’axe model and its applicability in Italy; and the third presents the results of an interdisciplinary study on the reactivation of the Civitavecchia -Capranica - Orte railway line.  The findings confirm that the Axis Contract is an effective tool for integrating urban and mobility planning, addressing accessibility needs, and promoting the sustainable rebalancing of territories.

Andrea Musso, Diego Rybski, Dirk Helbing et al.

The share of the world population living in cities with more than one million people rose from 11% in 1975 to 24% in 2025 (our estimates). Will this trend towards greater concentration in large cities continue or level off? We introduce two new city population datasets that use consistent city definitions across countries and over time. The first covers the world between 1975 and 2025, using satellite imagery. The second covers the U.S. between 1850 and 2020, using census microdata. We find that urban growth follows a characteristic life cycle. In the early stages of a country's urbanization process, large cities grow faster than smaller ones. At later stages, growth rates equalize across sizes. We use this life cycle to project future population concentration in large cities. Our projections suggest that 38% of the world population will be living in cities with more than one million people by 2100. This estimate is higher than the 33% implied by the well-known theory of proportional growth, but lower than the 42% obtained by extrapolating current trends.

Haozhe Xie, Zhaoxi Chen, Fangzhou Hong et al.

3D scene generation has garnered growing attention in recent years and has made significant progress. Generating 4D cities is more challenging than 3D scenes due to the presence of structurally complex, visually diverse objects like buildings and vehicles, and heightened human sensitivity to distortions in urban environments. To tackle these issues, we propose CityDreamer4D, a compositional generative model specifically tailored for generating unbounded 4D cities. Our main insights are 1) 4D city generation should separate dynamic objects (e.g., vehicles) from static scenes (e.g., buildings and roads), and 2) all objects in the 4D scene should be composed of different types of neural fields for buildings, vehicles, and background stuff. Specifically, we propose Traffic Scenario Generator and Unbounded Layout Generator to produce dynamic traffic scenarios and static city layouts using a highly compact BEV representation. Objects in 4D cities are generated by combining stuff-oriented and instance-oriented neural fields for background stuff, buildings, and vehicles. To suit the distinct characteristics of background stuff and instances, the neural fields employ customized generative hash grids and periodic positional embeddings as scene parameterizations. Furthermore, we offer a comprehensive suite of datasets for city generation, including OSM, GoogleEarth, and CityTopia. The OSM dataset provides a variety of real-world city layouts, while the Google Earth and CityTopia datasets deliver large-scale, high-quality city imagery complete with 3D instance annotations. Leveraging its compositional design, CityDreamer4D supports a range of downstream applications, such as instance editing, city stylization, and urban simulation, while delivering state-of-the-art performance in generating realistic 4D cities.

Wayne S Singh

This paper investigates the relationship between smart city initiatives and evolving urbanization trends in the United States. The research addresses the critical issue of rapid urban growth in the U.S. and explores how innovations within the smart city paradigm influence urban development. Utilizing principles from Urban Complexity Theory, this study identifies four key variables relevant to smart cities and their impact on urbanization: smart city technology, government policy, environmental sustainability, and socioeconomic factors. A mixed-method approach, combining quantitative and qualitative methodologies, was employed. A web-based survey (n=50) utilizing a five-point Likert scale was conducted among residents of Manhattan, New York, and Capitol Hill, Seattle. Results indicate that the implementation of smart city technologies is significantly associated with shifts in population density, land use diversification, and enhanced infrastructure dynamics. Additionally, residents demonstrated preferences for smart cities based on efficient urban mobility, environmental sustainability, and personal socioeconomic improvements. The findings highlight essential considerations for urban planners, policymakers, and employers. This study concludes that incorporating the identified influential factors into strategic urban planning optimizes city development to better accommodate growing urban populations.

Mingli Pang, Jieru Wang, Mingyue Zhao et al.

BackgroundDriven by the accelerated aging of the population of China, the number of older adults has increased rapidly in the country. Meanwhile, following children, migrant older adults (MOA) have emerged as a vulnerable group in the process of fast urbanization. Existed studies have illustrated the association between social support and loneliness and the relationship between sleep disturbance and loneliness; however, the underlying mechanisms and the migrant-local difference in the association between social support, sleep disturbance, and loneliness have not been identified. ObjectiveThis study aimed to clarify the migrant-local difference in the relationship between social support, sleep disturbance, and loneliness in older adults in China. MethodsMultistage cluster random sampling was used to select participants: 1205 older adults (n=613, 50.9%, MOA and n=592, 49.1%, local older adults [LOA]) were selected in Weifang City, China, in August 2021. Loneliness was assessed with the 6-item short-form University of California, Los Angeles Loneliness Scale, social support was evaluated with the Social Support Rating Scale, and sleep disturbance was measured with the Pittsburgh Sleep Quality Index. The chi-square test, t test, and structural equation modeling (SEM) were adopted to explore the migrant-local difference between social support, sleep disturbance, and loneliness among the MOA and LOA. ResultsThe mean score of loneliness was 8.58 (SD 3.03) for the MOA and 8.00 (SD 2.79) for the LOA. SEM analysis showed that social support exerts a direct negative effect on both sleep disturbance (standardized coefficient=–0.24 in the MOA and –0.20 in the LOA) and loneliness (standardized coefficient=–0.44 in the MOA and –0.40 in the LOA), while sleep disturbance generates a direct positive effect on loneliness (standardized coefficient=0.13 in the MOA and 0.22 in the LOA). ConclusionsBoth MOA and LOA have a low level of loneliness, but the MOA show higher loneliness than the LOA. There is a negative correlation between social support and loneliness as well as between social support and sleep disturbance among the MOA and LOA (MOA>LOA), while loneliness is positively associated with sleep disturbance in both populations (MOA<LOA). Measures should be taken by the government, society, and families to increase social support, decrease sleep disturbance, and further reduce the loneliness among older adults, especially the MOA.

Armand Fréjuis Akpa, Augustin Foster Chabossou

The introduction of information and communication technology (ICT) has altered the way society operates things. ICT is used in various sectors, including agriculture. It can be used in the agricultural sector to distribute pricing and encourage agricultural commodity exports. The study aims to investigate the effect of ICT on cashew nut export in Benin using an autoregressive distributed lag (ARDL) approach. Data were collected over the period of 31 years (1990–2020) in Benin. The estimated results showed that mobile cellular telephone subscription is negatively and significantly correlated with cashew nut export in the short-run. However, in the long-run, it exhibits a positive and significant correlation. On the other hand, internet usage had no significant effect on cashew nut export in the short-run, but negatively influenced cashew nut export in the long-run. These results suggest that to increase its cashew nut export, the Beninese government should invest in technological infrastructure to improve internet access by reducing the cost of internet and increasing education that will allow farmers to better understand and use ICT.

David Oluseun Olayungbo, Aziza Zhuparova, Mamdouh Abdulaziz Saleh Al-Faryan et al.

The relationship between oil price movements and stock markets during the COVID-19 pandemic and the geopolitical crisis like the ongoing Russian-Ukraine war is yet unexplored extensively. This study therefore examines the return-correlation effects of oil prices on stock markets and their spillover effects in oil-exporting and European countries using daily closing data. After estimating the GARCH process, we employ the static and dynamic Markov Switching model that allow the relationship between oil price and stock market to switch between two regimes coined the COVID-19 and the Russia-Ukraine war periods. The static model shows stock price returns to respond positively and significantly to oil price returns in Italy, Germany and the US during the Covid-19 period while the response is significantly positive only for US in the Russia-Ukraine war period. As regards the volatility spillover, significant spillover is found from stock to oil market for Nigeria, vice versa for Saudi Arabia and bi-directional volatility spillover found for the US, Italy and Germany during the COVID-19 period. The policy implication is that Nigeria and Saudi Arabia should prioritize financial policy and energy policy respectively while US, Italy and Germany should adopt policy coordination to stabilize oil-stock market volatility during low oil price period like the COVID-19 period.

Federica Bianchi, Rossella Moscarelli

The conquest of new public spaces is one of the main options in processes of urban regeneration. It seems essential in contemporary cities, since our life occurs more and more indoors and in private contexts, reducing the role of public and outdoor activities. Among cultural-based urban regeneration projects that operate within those spaces waiting for an improvement of the existing public functions, schools can play a particularly prominent role, as well spread and symbolic institutions with an educational mission for young people. From this perspective, the paper discusses how school squares, namely the urban areas close to the entrance of schools, can be designed and regenerated to produce a real public space where the city meets the school and vice versa. The paper presents a methodology to classify different typologies of school squares, based on an extensive analysis on over 600 school squares, located in the provinces of Milan, Turin and Varese. On the basis of such classification, some guidelines are discussed in order to propose a strategy to redesign these symbolic spaces and to conquer them as public areas.

Haozhe Xie, Zhaoxi Chen, Fangzhou Hong et al.

3D city generation with NeRF-based methods shows promising generation results but is computationally inefficient. Recently 3D Gaussian Splatting (3D-GS) has emerged as a highly efficient alternative for object-level 3D generation. However, adapting 3D-GS from finite-scale 3D objects and humans to infinite-scale 3D cities is non-trivial. Unbounded 3D city generation entails significant storage overhead (out-of-memory issues), arising from the need to expand points to billions, often demanding hundreds of Gigabytes of VRAM for a city scene spanning 10km^2. In this paper, we propose GaussianCity, a generative Gaussian Splatting framework dedicated to efficiently synthesizing unbounded 3D cities with a single feed-forward pass. Our key insights are two-fold: 1) Compact 3D Scene Representation: We introduce BEV-Point as a highly compact intermediate representation, ensuring that the growth in VRAM usage for unbounded scenes remains constant, thus enabling unbounded city generation. 2) Spatial-aware Gaussian Attribute Decoder: We present spatial-aware BEV-Point decoder to produce 3D Gaussian attributes, which leverages Point Serializer to integrate the structural and contextual characteristics of BEV points. Extensive experiments demonstrate that GaussianCity achieves state-of-the-art results in both drone-view and street-view 3D city generation. Notably, compared to CityDreamer, GaussianCity exhibits superior performance with a speedup of 60 times (10.72 FPS v.s. 0.18 FPS).

Pratham Singla, Ayush Singh, Adesh Gupta et al.

Urban planning faces a critical challenge in balancing city-wide infrastructure needs with localized demographic preferences, particularly in rapidly developing regions. Although existing approaches typically focus on top-down optimization or bottom-up community planning, only some frameworks successfully integrate both perspectives. Our methodology employs a two-tier approach: First, a deterministic solver optimizes basic infrastructure requirements in the city region. Second, four specialized planning agents, each representing distinct sub-regions, propose demographic-specific modifications to a master planner. The master planner then evaluates and integrates these suggestions to ensure cohesive urban development. We validate our framework using a newly created dataset comprising detailed region and sub-region maps from three developing cities in India, focusing on areas undergoing rapid urbanization. The results demonstrate that this hybrid approach enables more nuanced urban development while maintaining overall city functionality.

Hao Wang, Chao Mei, Jiahong Liu et al.

P. Fan, Z. Ouyang, D. D. Nguyen et al.

Abstract We used the experiences of Vietnam following the economic reform, known as Doimoi, to study urbanization, economic development, and environmental and social changes in transitional economies at multi-scales. The country underwent rapid urban land expansion, as indicated by the increase in the mean value of nighttime light data from −1.4 in 1992 to 4.4 in 2012. The urban population grew at a faster annual rate following Doimoi (1986–2015) compared to the pre-Doimoi period (1960–1985). At the inter-city level, cities with populations more than 1 million experienced more rapid growth of built-up land intensity and population size compared to the national average. At the intra-city level, conversion from farmland contributed significantly to built-up land in Hanoi and Ho Chi Minh City from 1990 to 2010. As indicated by PM2.5 and NO2 concentrations, urban environments in large cities deteriorated; yet poverty was alleviated, as measured by populations falling under the poverty line and the proportion of the urban population living in slums. Coupled dynamics of urbanization, economic development, and environmental and social changes were modeled and the main findings are: (1) economic development strongly influenced urbanization and (2) urbanization and economic development contributed to environmental deterioration while promoting the social conditions. How urban land expansion was facilitated by local institutional interventions such as frequent changes of administrative boundaries, master plans, and policies is also discussed. Our study highlighted a multi-scale and multi-dimensional perspective, the independent and coupled relationships between economic development, urbanization, and environmental/social changes, and a hybrid approach of examining the influences of the institutional intervention and the market mechanism on urbanization in transitional economies.

P. Iamtrakul, A. Padon, J. Klaylee

The metropolis of Bangkok is characterized as a primate city because of its role as the capital of Thailand. Its suburbanization spreads to five surrounding provinces. Compared to other provinces in Thailand, it has highly concentrated urban development, without disparity between urban and rural areas. Furthermore, the travel volume in Bangkok and its surrounding areas is the highest in the country, with the majority related to private vehicle usage. This is why Bangkok is ranked as the world’s most congested city. To solve this problem and sustain the urbanization of the capital, it is necessary to understand the urban development patterns in Bangkok and their associated factors in measuring the accessibility of transportation. This research applied factor analysis and cluster analysis to characterize the different district contexts of the Bangkok Metropolitan Region, by selecting the Bangkok Metropolitan Administration (BMA) as the capital city area and Pathum Thani Province as a suburbanized area. Consequently, their transport accessibility could be represented by the level of accessibility in terms of the inequalities in the existing transportation system. Furthermore, by clustering the districts according to their economic and social factors, the causes of these inequalities could be identified by spatializing and geographically highlighting them. These findings should be integrated into the urban planning and development policies to overcome urban development challenges and create a city with more accessible and affordable public transport opportunities.

Michael Tuffour

This study assessed how urban farmers survive land scarcity challenges in the midst of rapid urbanization in a developing country such as Ghana. As land scarcity becomes more pronounced in urban areas, farmers struggle to find a place to farm within the urban space but the numerous opportunities that come with farming within the city still inspires them to find spare lands and open spaces in the city to farm. Therefore, the study examined the factors that influence urban farmers’ mobility with respect to farmland in the midst of intense land scarcity. Reponses from 251 farmers were analyzed with both Tobit and Ordinary Least Squares (OLS). Land situation factors such as land ownership type, land scarcity challenges, and size of land were found to be associated with farmers’ mobility. Farm characteristics such as level of market benefits, intensity of vegetable production, and level of technology were also associated with farmers’ mobility within the city. Personal characteristics such as age, level of education, level of farmer engagement, and marital status also played a role. This implies urban farming sustainability requires conscious government efforts to include urban agriculture in its spatial planning decisions since there are numerous opportunities for farming within the city.

M. Kabir, Tapos Kormoker, M. Islam et al.

Riaz ul Hissan, Liaqat Ali Waseem, M. Khurshid et al.

It is estimated that 50% of the world's population is living on only 2% of land area. Population scientists also believe that the urban population will increase from 80% to 90% by 2030 which is why urban growth is a significant problem in the developing world. Rapid urbanization has created many problems like haphazard development, disturbance in the ecological system, shortage of shelter and food polluted environment, lack of basic facilities, and traffic congestion. Besides traffic jams, traffic flow is also the major reason for different types of pollution like noise pollution and air pollution, which is a cause of health problems. Pakistan being a developing country experiences the same problems because of rapid urbanization. Faisalabad is the third largest city (according to the rank-size rule) and is famous for the agro cottage and textile industry. It covered the 313.21km2 area. Traffic congestion is a significant problem in Pakistan’s cities because of their unplanned infrastructure and explosive population growth. Faisalabad is the first planned city of the subcontinent. With time, Faisalabad’s infrastructure faced many changes due to uncontrolled urbanization. Road transport increased by 3% yearly due to the usage of personal automobiles. In the usage of personal vehicles, the share of motorcycles is 89 % while the share of cars is 50 %. Rapid urbanization is a severe threat to the city environment. Traffic congestion has become the problem of the day.  This menace increased over time due to the slow development of roads and insufficient infrastructure as compared to rapid urbanization.

B. Q. Nguyen, T. Tran, Maria Grodzka-Łukaszewska et al.

In the present day, the acceleration of urban surface heat impacts resulting from urbanization and industrialization is critical for citizens and municipal governments in developing-country cities. The previous key findings have indicated the association between urban surface heat and the following areas: forests, mixed agricultural land, built-up area, and water bodies. This study was motivated by a lack of knowledge regarding the variation of temperature, evaporation, and humidity in Central Vietnam’s major region. The non-parametric Mann–Kendall test, Sen’s slope estimator, and Landsat image analysis were employed to determine the trend and statistical significance of the variables across the 42-year study period for Da Nang city and Quang Nam province. Our results show that Da Nang city has a consistent trend with a high correlation between temperature, evaporation, and relative humidity, whereas Quang Nam province showed an inverse relationship between temperature and relative humidity since the beginning of the regional urbanization. The maximum, minimum, and mean temperatures have increased by at least 0.29 °C in Quang Nam province and 0.71 °C in Da Nang city since 2000. Between 1979 and 2021, the frequency of days with temperatures exceeding 35°C has increased by two and seven days during the past decade at the meteorological stations in Da Nang and Tam Ky, respectively. The temperature in Da Nang city varied from 31.80°C to 32.82°C with high temperatures concentrated in urbanized regions with less coverage of small trees, plants, and water bodies. Thus, the results of this study will serve as a scientific basis for decision-makers and regional officials for land-use management and to increase community awareness of sustainable planning, particularly in Da Nang city and Quang Nam province in Central Vietnam.