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The Chinese authorities issued the "Guiding Opinions on Further Deepening the Reform of the Household Registration System" in 2014. This policy maintained strict controls on urban hukou in megacities, while slightly less stringent controls were applied in large cities. However, the restrictions on obtaining urban hukou were significantly relaxed in medium-sized cities and completely lifted in small cities. This study examines the causal effects and underlying mechanisms of hukou reform on urban innovation in cities of different sizes, using DID method based on a quasi-natural experiment by the 2014 hukou reform in China. The findings suggest that the hukou reform can significantly promote urban innovation, with particularly strong positive effects observed in large cities in the eastern region, small- and medium-sized cities in the central and western regions, as well as cities with favourable conditions for innovation. The primary mechanisms in which hukou reform influences urban innovation involve enhancing both the quantity and quality of urban labor force, as well as creating a better environment for innovation in cities. [ABSTRACT FROM AUTHOR]

Background: India currently accounts for a majority of global suicide deaths. Research in European ancestry has established that suicide mortality has a significant genetic component, and suggests that inflammation may play a crucial role in the pathophysiology of suicide. Inflammation is also highly relevant in regions of increased pollution exposure, such as the megacities of India. To address the existing gaps in genetic research on suicide and possible association with inflammatory biomarkers, we examined genetic polymorphism and clinical risk phenotypes in a population-based suicide-death cohort, India. Material and methods: Genotyping of IL-1β(rs16944) & (rs1143627), IL-4(rs2070874), IL-6(rs1800795) and IL-10(rs1800896) was done in 234 post-mortem suicide-death cases and 256 post-mortem controls (N = 490) using PCR RFLP method. Results: Our analyses identified three significant (p < 0.001) associations of cytokine variants with suicide death, including IL-1β(rs16944), OR = 0.627; IL-4(rs2070874), OR = 0.524; and IL-6(rs1800795), OR = 2.509. Cases were more likely female and were more likely to have a history of psychiatric illness, though rate of psychiatric illness was low in suicide cases(9%). Conclusion: Our genetic results are generally consistent with previous research on risk for depression and suicidal behaviour, and both genetic and phenotypic results provide new insights into risk factors that may contribute to suicide in India. [ABSTRACT FROM AUTHOR]

AbstractIn limited-resourced Latin-American cities, adapting urban regulations and capturing value offers great potential for developing affordable land. We explored what counts for the significant variance in local land management implementation within Buenos Aires Metropolitan Region. Analysed municipalities successfully developed high-quality instruments to expand affordable land markets. However, local planning effectiveness does not find limits in the quality of planning itself. Depending on the municipalities’ relative location within the metro area, the national-level pipeline infrastructure plans, the politically driven finance choices, and divergent administration protocols favour or hinder the capacity to implement an effective urban land development strategy at local levels. [ABSTRACT FROM AUTHOR]

Understanding the spatially varying effect mechanism of intermodal connection on metro ridership helps policymakers develop differentiated interventions to promote metro usage, especially for megacities with multiple city sub-centers and ring roads. Using multiple datasets in Shanghai, this study combines Light Gradient Boosting Machine (LightGBM) with Shapley additive explanations (SHAP) to explore these effects with the consideration of the built environment and metro network topology. Results show that the collective impacts of intermodal connection are positive, not only within the main city but also alongside the main commuting corridors, while negative effects occur in the peripheral area. Specifically, bike sharing trips increase metro ridership within the inner ring of the city, while bus services lower metro usage at stations alongside the elevated ring roads. Parking facilities enable metro usage at city sub-centers, and the small pedestrian catchment area increases metro riders alongside the main commuting corridors. Empirical findings help policymakers understand the effect mechanism of intermodal connection for stations in different regions and prioritize customized planning strategies. [ABSTRACT FROM AUTHOR]

With urban rail transit (URT) systems playing an increasingly crucial role in megacity mobility, the rising frequency of service disruptions may pose substantial passenger delays and safety concerns. This emphasizes the need to prioritize resilience enhancements for the URT system. Bus bridging, an effective resilience-enhancing measure, faces challenges that effectively capture the unique features of bridging buses and stranded passengers, and rely on predetermined routes and fixed frequencies, diminishing service flexibility and efficiency in dynamic bridging environments. To overcome these challenges, we propose a novel approach using a multi-agent reinforcement learning model. This model treats bus bridging as a collaborative multi-agent task with the competition. Specifically, it enables bridging buses to adaptively select the next visiting station based on environmental characteristics. Furthermore, a competitive reward function is introduced to facilitate effective collaboration among all agents while preventing malicious competition. The case study results demonstrate that the proposed enhancing resilience method outperforms traditional reinforcement learning method and classic bus bridging strategy and can reduce the average waiting time and average travel time, especially in resource-limited and complex scenarios. [ABSTRACT FROM AUTHOR]

Urban-suburban-rural (U-S-R) zones exhibit distinctive transitional characteristics in interaction between human and nature. U-S-R transition zones (U-S-RTZ) are also highlighting the function diversity and landscape heterogeneity across territorial spaces. As a super megacity in western China, Chengdu's rapid urbanization has driven the evolution of U-S-R spaces, resulting in a sequential structure. To promote the high-quality spatial development of urban-rural region in a structured and efficient manner, it is essential to conduct a scientific examination of the multidimensional interconnection within the U-S-RTZ framework. By proposing a novel identification method of U-S-RTZ and taking Chengdu, China as a case study, grounded in a blender of natural and humanistic factors, this study quantitatively delineated and explored the spatial evolutions of U-S-RTZ and stated the optimization orientation and sustainable development strategies of the production-living-ecological spaces along the U-S-R gradients. The results show that: 1) it is suitable for the quantitative analysis of U-S-RTZ by established three-dimensional identification system in this study. 2) In 1990–2020, the urban-suburban transition zones (U-STZ) in Chengdu have continuously undergone a substantial increase, and the scale of the suburban-rural transition zones (S-RTZ) has continued to expand slightly, while the space of rural-ecological transition zones (R-ETZ) has noticeably compressed. 3) The landuse dynamics within U-S-RTZ has gradually increased in 1990–2020. The main direction of landuse transition was from farmland to construction land or woodlands, with the expansion of construction land being the most significant. 4) R-ETZ primarily focus on ecological functions, and there is a trade-off relationship between the production-ecological function within the S-RTZ, and in the U-STZ, production-living composite functions are prioritized. This study emphasizes the importance of elastic planning and precise governance within the U-S-RTZ in a rapid urbanization region, particularly highlighting the role of suburbs as landscape corridors and service hubs in urban-rural integration. It elucidates to the practical implications for achieving high-quality development of integrated U-S-R territorial spaces. [ABSTRACT FROM AUTHOR]

Metro systems play an important role in reducing urban traffic congestion and promoting the sustainable development of urban transport in megacities. With the expansion of a metro network, transfer stations are necessary for increasing the service connectivity of a metro network. An accurate estimation of transfer passenger flow can help improve the operations management of a metro system. This study proposes a data‐driven methodology for estimating the transfer passenger flow volume of each transfer station in a metro network by mining smart card data. The estimated transfer passenger flow data are visualized to show the spatial‐temporal distribution characteristics of metro transfer passenger flow. The case study results of the Shenzhen Metro network demonstrate that the proposed data‐driven methodological framework is very effective in estimating different types of transfer passenger flows, such as total transfer passenger flow, hourly transfer passenger flow, and inbound and outbound transfer flows at each transfer station. The spatial‐temporal distribution characteristics of transfer passenger flow can be very useful for designing effective and efficient passenger flow management measures to ensure the safe and efficient operation of a metro system. [ABSTRACT FROM AUTHOR]

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Ongoing urbanization around the world is leading to changes in ecosystems, and wildlife is forced to respond by adapting to them. First of all, disturbance concern plant communities, which are transformed in and around the city actively. Changes in phytocenosis along with the stress of the human presence also affects animals, what often leads to a decrease in small mammal community biodiversity in places subject to anthropogenic influence. However, for some mammalian species (especially small ones) that are more resistant to stress from human presence, urbanization has its advantages by creating modified habitats and reducing competition with native species that are more sensitive to urbanogenic effect. For several years, we have been studying the influence of the megalopolis (Ekaterinburg city) located in the forest zone on communities of small mammals in sites of pine forest transformed to different degrees depending on the proximity to urban development (two park-forests), as well as in the Central Culture and Recreation Park (in places with different attendance level). The forest phytocenoses were found have been altered throughout the entire park-forest sites due to weed vegetation and introduced plant species, as well as under the influence of recreation especially strongly in places adjacent to developments. The micromammal communities of all sites, in addition to forest rodents, are present hemisynanthropic species that are not characteristic of this zone forest (the small wood mouse and the striped field mouse). In outlying park-forest places where the anthropogenic load is much lower, forest mammal species are found in greater numbers, although the presence of hemisynanthropic species remains. In some cases, this might lead to an increase in community diversity indices. Naturally the conditions of the plant environment affect the ability of rodents and shrews to form steady micropopulations and communities in the forest sites of the city outskirts, although and the anxiety factor plays a significant role. [ABSTRACT FROM AUTHOR]

With the booming of Big Data and the Internet of Things, various urban networks have been built based on intercity flow data, and how to combine them to learn a more comprehensive understanding of mega-city regions is becoming more and more indispensable. In this paper, we designed a graph-based multi-view clustering method based on graph learning to explore the mega-city region structures from multi-source data. An example of clustering analysis consists of the people flow network, cargo flow network, and information flow network, covering 88 cities from Beijing, Tianjin, Hebei Province, Shandong Province, Henan Province, Jiangsu Province, Anhui Province, Shanghai, and Zhejiang Province in China is used to illustrate the applicability of the idea in super mega-city region scale studies. Utilizing the proposed clustering method, a unified network representation is calculated, and 5 mega-city regions, Beijing-Tianjin-Hebei Cluster, Henan Cluster, Shandong Cluster, Shanghai-Jiangsu-Anhui Cluster, and Zhejiang Cluster, are detected based on intercity flow networks. City-to-city flows, including Luan-Taizhou, Lianyungang-Chuzhou, and Xuzhou-Bengbu of the people network, Shanghai-Hangzhou, Suzhou-Shanghai, and Shanghai-Ningbo of the cargo network, Shanghai-Hangzhou, Bozhou-Jinhua, and Huaibei-Bozhou of the information network, are suggested to be further enhanced to facilitate the ongoing nationwide constructions of urban agglomerations in China. The multi-view clustering method proved to be a helpful calculation framework for mega-city region analysis, which would also be considered as a substantial foundation for further urban explorations with more advanced graph learning techniques. [ABSTRACT FROM AUTHOR]

Urban informality remains a central challenge for those engaged in understanding and transforming global South cities. There have been calls to develop new conceptual language geared to this challenge and much debate around the degree to which it might be subsumed within global urban theory. We argue that theories of informal urbanism need to be grounded in an understanding of how it works to sustain livelihoods, moving beyond studies of informal settlement, street vending and transport to understand the synergies, interrelations and interdependencies between them. Informal vending and transport provide employment and produce cheap goods and mobility; informal settlement produces affordable housing in key locations with access and mobility. 'Inventraset' is a portmanteau concept that links in formal ven ding, tra nsport and set tlement into a dynamic urban assemblage that is invent ive, tra nsgressive and set tled. This model is demonstrated through an empirical study of the spatial logic of the inventraset triangle within the megacities of Manila and Jakarta. Here the informal is normal, whether displayed in the intensities of transit nodes and street markets or camouflaged within zones of exclusion. This is not an 'informal city' but one where informal street vending, transport and settlement are geared to formal spatial and governance structures in different ways in different neighbourhoods − an assemblage of informal/formal and of vending/transport/settlement without which the urban economy would collapse. This is a call not simply to rename the informal but to understand it as a mode of production that is more than the inverse of the formal. [ABSTRACT FROM AUTHOR]

Plant communities are impacted by local factors (related to environmental filtering) and landscape factors (related to dispersal limitation). While many studies have shown that the relative importance of these factors in understanding plant community dynamics due to urbanization, little is known about how they are altered by urbanization—a significant threat to biodiversity. This study evaluates the relative importance of local environmental (local factors), landscape, and spatial (landscape factors) variables that influence plant communities in 34 urban green spaces comprising two different habitats (forests and grasslands) along the urban–rural gradients in the Tokyo megacity, Japan. To continuously assess the relative importance of each factor along the urban–rural gradients, we extracted 1000 landscapes within a certain range that contained several sites. Subsequently, the relative importance of each factor and urbanization rate (proportion of artificial built‐up area) were estimated for each landscape. Our study found that the relative importance of both local and landscape factors decreased, while that of local factor for native species in forest habitats and that of landscape factors for native species in grassland habitats increased. Collectively, these findings suggest that city size and habitat characteristics must be considered when predicting changes in plant communities caused by urbanization. [ABSTRACT FROM AUTHOR]

During rapid urbanization, megacities see disparities in the spatial distribution of basic public service facilities and the urban built environment. Current research on basic public service facilities focuses on equal spatial distribution, leading to the overlook of their match with the surrounding built environment. Based on a case study on education, healthcare, and elderly care facilities in Chengdu central urban area, this paper analyzes the spatial distribution of these facilities and the built environment, and examines their spatial matching degree using a bivariate spatial autocorrelation model. The findings reveal the following insights: firstly, education and healthcare facilities present a "one core and multi-center" spatial distribution pattern, with the city center serving as the core and suburban subdistricts acting as the multiple centers, while elderly care facilities present a core-edge distribution pattern in contrast; secondly, the built environment presents a core-edge radial distribution pattern, with the city center acting as the nucleus that connects suburban subdistricts; thirdly, the spatial matching degree between the facilities and the urban built environment from the city center outwards is characterized by high, low, medium, and high levels. Notably, a significant spatial mismatch is observed in urban-rural transitional zones. In light of these findings, the paper comes to a conclusion that during urbanization, the efforts to equalize basic public service facilities in the urban-rural transitional zones may lead to spatial mismatches, to which urban planners and managers should pay close attention. [ABSTRACT FROM AUTHOR]

Climate change is becoming an increasingly significant issue in Africa, and the need for climate resilience assessment has intensified. Dar es Salam is one of Africa's emerging megacities. With a population of over seven million, which continues to grow, there is an urgent need to understand the city's ability to deal with natural disasters. The Climate Disaster Resilience Index (CDRI) was used in this study to assess the city's ability to withstand and cope with climatic hazards. The Index was quantified using sets of dimensions (social, physical, economic, natural, and institutional), with various parameters indicating the city's abilities, strengths, and vulnerabilities to potential climate‐related disasters. Despite being moderately resilient to climate change disasters, the results of our study indicate that the city's economic and institutional features obtained the lowest scores and the least resilience level. The study's findings provide a perspective on aspects of the city management sectors in terms of resilience and which should be given greater consideration in order to strengthen the city's current and future resilience. [ABSTRACT FROM AUTHOR]

The massive reductions in anthropogenic emissions resulting from the COVID-19 lockdown provided a unique opportunity to evaluate the effect of mitigation measures aiming to abate air pollution. In Mexico, the total lockdown period took place during the dry-hot season when biomass burning activity is enhanced. Here, we investigate the role of biomass burning emissions on regional ozone levels in the Megalopolis of Central Mexico. The studied period covers the lockdown phases 2 and 3, and the first month of the New Normal. We applied a factor separation technique and process analysis to estimate the pure and synergistic contributions of emission reductions under lockdown and that from biomass burning to daily ozone maximum concentrations in 7 metropolitan areas of different states in the Megalopolis. The results revealed that biomass burning plumes likely masked the effect of massive reductions from mobile emissions, impacted the PBL development during phase 3 and favored transition and mixed NO x -limited and VOC-limited regional regimes. This contributed to increased ozone production in the middle to lower PBL by changing the regional background levels which potentially could bias high ozone production efficiency estimations. Given the Megalopolis contribution to economic and societal development at national scale, our study suggests that ozone mitigation measures during the dry-hot season targeting mainly mobile emissions will likely be offset by biomass burning plumes. A regional and synergic policy aiming to control biomass burning would help to reduce the occurrence of high ozone levels in Central Mexico with the co-benefit of tackling short-lived climate pollutants. [ABSTRACT FROM AUTHOR]

Concerns about climate change are driving the development of novel technologies for mitigation and adaptation. Some of them include electricity generating and water harvesting based on atmospheric humidity. The latter is already commercial and can generate 50 L of drinking water per day per capita for dozens of people; however, besides energy, operation requires sufficient levels and durations of humidity and temperature. Our study focuses on the 33 megacities of the world, characterising the humidity and heat stress regimes during the last decade, using data from meteorological stations in their vicinity, and ranking them by their exposure and vulnerability to intense heat stress and their suitability to use these moisture‐reliant technologies. Our findings indicate the dominance of severe heat stress conditions in megacities located in developing countries. Ranking the megacities according to the intensity and duration of the heat stress shows the annual, monthly and hourly courses. The five most affected are the cities of Chennai, Bangkok, Kolkata, Karachi and New Delhi. Seven megacities suffer continuous, at least 12 h, of intense heat stress during 1–4 months. The ranking also considered the level of income of the countries, hence their vulnerability. On an annual basis, approximately half of the megacities are highly suited for moisture‐reliant technologies, among them megacities ranked as the top three in exposure to intense heat stress conditions—Chennai, Bangkok and Kolkata. When focusing on the humid season, 27 out of 33 megacities (82%) obtain suitable conditions for the new technologies and thus can benefit from them, at least part of the year. The implementation of humidity technologies for green energy and clean water could be of great help as our world gets more populated, warmer with higher water demand, especially for populations with insufficient infrastructure and resources. [ABSTRACT FROM AUTHOR]

Background: The concept of Hyperconnected Megacity Parcel Logistics (HMPL) was introduced in 2018 and aims to enhance the efficiency, responsiveness, resilience, and sustainability of parcel movements in megacities. However, evaluating such fundamental solutions presents challenges and requires a comprehensive understanding of all stakeholders and decisions involved. Methods: This study introduces a discrete-event agent-based simulation platform that encompasses critical stakeholders and addresses various levels of decision-making. This platform provides an opportunity to evaluate key decisions within an HMPL structure. Results: To demonstrate the capability of the simulator, we assess the impact of package routing and consolidation strategies facilitated by HMPL compared to traditional practices. Preliminary findings suggest that increased interconnection among nodes in HMPL reduces transit times, thereby enabling tighter customer delivery services. However, examining different consolidation heuristics reveals potential trade-offs between handling and shipping costs under fixed shipment schedules, prompting further investigation into dynamic shipment services. Conclusions: The findings of this study suggest that the benefits of innovative approaches in a complex environment, such as parcel logistics, cannot be evaluated in isolation from other decisions. Accurate assessment of the ultimate outcomes and underlying trade-offs requires multi-faceted models that incorporate all key variables. [ABSTRACT FROM AUTHOR]

In this study, we consider the introduction of new mobility services and technologies into the megacity of Beijing, China, as per developed strategy and action plans, in order to investigate their potential contribution to sustainable mobility. This includes population relocation (decentralization), the construction of new rail lines, the introduction of shared bike services as a feeder to subway stations, the electrification of passenger vehicles and the adoption of automated and shared vehicles. The well-established, system dynamics-based MARS model is adapted to Beijing and further improved via the inclusion of these new services, technologies and policies. We find that decentralization can have a profound effect on overall sustainability if not considered in conjunction with other policies and that new rail lines and shared bikes may only have benefits in specific zones. Shared and automated vehicles could increase VKT by 60% and reduce active and public transport trips by a quarter. As such, nuanced integrated policy approaches will be required that are similar to those currently in place, such as imposed car shedding and taxi fleet control. [ABSTRACT FROM AUTHOR]

The idea of a modern city is hardly construed from the prism of religion, even though the Tower of Babel has been discursively engaged as an agenda of building a megacity with an interplanetary goal. During the development and expansion of Christianity, cathedrals, with their elaborate architectural aesthetics and frequently as the only spectacular buildings in the provinces, became sites of ecclesiastical and political power. In Nigeria, although the mainline churches followed the cathedralization pattern of Western Christianity, the Pentecostal churches preferred the establishment or construction of prayer camps as the earliest mode of development and sacralization of space. However, there is a transition from prayer camps to prayer cities, with the latter conceived as a deliberate urbanization policy that embraces modern facilities. Using ethnographic and analytical methods, I study the Mountain of Fire and Miracles Ministries' Prayer City near Lagos, Nigeria, a "city" built on and sustained by prayer culture, and a "city" that invigorates urban life. [ABSTRACT FROM AUTHOR]

Urbanization in tropical landscapes is a complex phenomenon that can lead to community shifts rather than simple species extinction in response to multiple stressors in peri-urban and urban settings. We have investigated the impacts of different stressors along a tropical urban-peri-urban gradient on the bee community, the health of which is a global conservation concern. Several stressors such as increased built-up area, pesticide application and air pollution may effectively regulate bee community composition and corresponding functional diversity along urban-peri urban gradients. We investigated the changes in bee community structure in response to associated stressors in 20 locations including parks and gardens along an urban-peri-urban gradient surrounding the megacity of Kolkata. Bee community structure differed significantly between urban and peri-urban sites with urban sites showing lower value of nestedness. Network analysis also revealed that Apis florea and Lasioglosssum sp. 1 were the most important species in the urban and peri-urban areas respectively, as they had the highest values in bee-site network parameters. Functional diversity increased with urbanization and decreased with pesticide toxicity. Functional redundancy decreased with urbanization. Individual stressors impacted the bee assemblage differentially along the urbanization gradient. SO2 and pesticide toxicity negatively influenced bee abundance and diversity. Urban sites sustained more specialized species and therefore are more vulnerable to shocks while peri-urban sites had a more functionally redundant community making it comparatively more resilient. [ABSTRACT FROM AUTHOR]

This paper is part of a series of research that these authors are conducting to study the linguistic landscape of the Tokyo megacity. In this instance, our focus lies on Shinjuku city. However, our examination does not extend to the linguistic landscape of the city itself; rather, it zeroes in on a café situated at its core, the Café Lavandería. How did Café Lavandería contribute to the development of the Hispanic linguistic, sociolinguistic, and subversive landscape in central Tokyo? The research unfolds in various segments. Initially, contextualization introduces the reader to Tokyo and Shinjuku; subsequently, the significance of Café Lavandería and the subversive social and political movements in Japan are elucidated. Following this, the study's foundation, including the photographic evidence and corresponding data, is presented. Lastly, an analysis of these data is conducted, culminating in an evaluation of Café Lavandería's impact in Japan. [ABSTRACT FROM AUTHOR]

Rapid morphological and socioeconomic changes have accelerated the urbanization process and urban land use transformation in China. Megacities comprise clusters of urban cities and exhibit both newly formed and well-developed urban land use development beyond administrative boundaries. It is necessary to distinguish the changing effects of spatial-varying driving factors on newly formed urban land uses from well-developed built-up areas in megacities. This study proposed a multi-spatial urbanization framework to quantify region-level socioeconomics, cluster-level ecological morphologies, and grid-level urban functional morphologies. A three-level Bayesian hierarchical model was developed to investigate the impacts of multi-spatial driving factors on urban land use transformation in megacities. The study period focused on the urbanization process between 2000 and 2018 in Guangdong–Hong Kong–Macao Greater Bay Area (GBA). Results revealed that compared with well-developed urban built-up land, changing impacts of three-level driving factors in urban land use transformation could be captured based on the proposed Bayesian hierarchical model. The region-level total population was associated with increasing possibilities in forming new residential land than the well-developed ones in 35 districts/counties/cities in GBA. Cluster-level ecological attributes with higher proportion, lower edge density of urban built areas, and lower-degree ecological complexity showed increasing probability on newly formed industrial and public land. Grid-level urban functional factors including public transportation density and shopping/dining distribution exhibited significantly decreasing probability (coefficients: −2.12 to −0.51) on contributing newly formed land uses compared with the well-developed areas, whereas business/industry distribution represented higher (coefficients: 0.99 and 0.15) and lower probabilities (coefficient: −0.22) of forming industrial/public land and residential land separately. This research shows a new attempt to distinguish multi-spatial morphological and socioeconomic effects in urban land use transformation in megacities. [ABSTRACT FROM AUTHOR]

This study aims to start from the macroscale of the megacity, explore a top-down operational technical path from the identification of community regeneration units as the evaluation objects to the BID priority intervention evaluation, and then propose differentiated community regeneration strategies based on the BID model. In the post-epidemic era, it is necessary for global megacities to take new measures in urban regeneration to respond to worldwide changes and challenges. As an innovative tool to promote central city revitalization, the BID model has played an important role in community transformation. In the context of the continuous decentralization of population and industry in China's megacities, it is urgent to explore the technical path to apply the BID model to local community regeneration. Given the shortcomings of existing studies in the method to identify the scope of BID implementation and evaluate intervention priorities, this study takes Tianjin, a megacity in China, as an example and uses DBSCAN (density-based spatial clustering of applications with noise) and service area analysis to define the community regeneration units with commercial agglomeration characteristics as the objects. Then, the BID priority intervention evaluation system is constructed from the two measurement aspects of the intervention potential and the necessity of community regeneration to classify the BID intervention priorities of community regeneration units. The main conclusions are as follows: 1. When the DBSCAN analysis parameters take the minimum number of elements as 30 and the search distance as 120 m, the result is most suitable for identifying community units with commercial agglomeration of the study area; 2. Population vitality, especially working and residential population density, is the key factor affecting BID intervention potential, while road network density is an important indicator for determining the necessity of community regeneration; 3. Community regeneration units with high BID priority levels need to develop differentiated regeneration strategies combining their BID intervention potential, regeneration necessity characteristics, and location attributes. These conclusions can provide references for the governments of megacities to screen and establish BIDs. [ABSTRACT FROM AUTHOR]

Satellites provide global coverage for monitoring atmospheric greenhouse gases, crucial for understanding global climate dynamics. However, their temporal and spatial resolutions fall short in detecting urban‐scale variations. To enhance satellite reliability over urban areas, this study presents the first comprehensive analysis of long‐term observations of column‐averaged dry air mole fractions of CO2, CH4, and CO (XCO2, XCH4, XCO) using two ground‐based fourier transform infrared spectrometers, EM27/SUNs, in a megacity. With over 2 years of observations, our study shows that EM27/SUN measurements can effectively capture the daily and seasonal variability of XCO2, XCH4, and XCO over Seoul, a megacity with complex topography and various emission sources. In addition, we use the advantage of having multiple greenhouse gas satellites targeting Seoul to compare with the EM27/SUNs. Our study highlights the importance of EM27/SUN observations in Seoul to identify the need for improvements in satellites to monitor greenhouse gas behaviors and emissions in urban areas. Plain Language Summary: This study examines how accurately satellites can monitor greenhouse gases over urban atmospheres to understand climate change. While satellites are good at covering large areas, they struggle to detect changes in cities. To improve these setbacks, this study uses ground‐based instruments to measure greenhouse gases over 2 years and test satellite reliability over Seoul, a megacity with various emission sources as well as a complex terrain for observation. This study shows that the newly developed ground‐based instruments, EM27/SUNs, are effective in tracking daily and seasonal changes in greenhouse gas concentrations and are useful tools in improving the validity of satellite observations in urban areas. The study suggests that using ground‐based observations in addition to satellite data adapted for urban area monitoring is important for understanding greenhouse gas emissions in major cities like Seoul. Key Points: First results of long‐term EM27/SUN measurements and satellite comparisons over SeoulEM27/SUN effective in monitoring greenhouse gases and assessing validity of satellite measurements over urban areasSatellites need higher resolutions and locally validated algorithms for urban monitoring [ABSTRACT FROM AUTHOR]

İstanbul is the largest city located in the Mediterranean Basin and has a medium to high risk of climate change and future climate risks. Changes in temperature and other weather variables have had significant impacts on İstanbul. In this context, there is a need for studies on the issues of climate monitoring and climate change vulnerability to reduce the adverse impacts. The aim of this study is to investigate the temperature trends of synoptic weather station in İstanbul Atatürk Airport between 1973 and 2023 to have a general idea about how the temperature has changed over the last half-century and to establish statistically whether a trend is significant or not. The values of minimum (Tmin), maximum (Tmax) and mean (Tmean) temperature related parameters were estimated. Annual, monthly and seasonal temperature trends are also analyzed. The findings of this study indicate a significant (p < 0.001) rise in the mean air temperature (Tmean) of İstanbul over the past 51 years (1973–2023), with an annual warming trend of 0.06 °C. The strongest increasing trend in seasonal mean air temperatures has been observed in the summer season, with an increase of 0.08 °C per year. The trend analysis also shows a statistically non-significant increase in yearly average minimum temperature (Tmin) between 1973 and 2023, with a rate of 0.04 °C per year. However, the annual maximum temperature (Tmax) has shown no changes. [ABSTRACT FROM AUTHOR]

We hereby present the variability of fine particles (PM1 ≤ 1 micron) that has not yet been investigated under the influence of COVID-19-induced lockdown in three major cities of different climatic zones in India. We unfold the baseline level of PM1, a level to which the population is chronically exposed and extremely critical for epidemiologists for fixing health markers. This has been achieved using the saturation point methodology under fair weather conditions. The baseline level of PM1 for Delhi and Mumbai is found to be 13 µg m− 3 and 9 µg m− 3, respectively. The processes leading to a significantly higher decline in the level of PM1 as compared to coarser particles (PM2.5) are discussed. The varying magnitude of the declining trends in PM1 is found to be linked to the intensity of residential emissions, which vary from one city to another and was exempted during lockdown. Our findings are critical in understanding the dominant role played by different sources of PM1 in framing effective health risk management policies. Highlights: The reduction in PM1 is found to be significantly higher than that of PM2.5 during a lockdown. The baseline level is found to be 13 µg m− 3 for Delhi and 9 µg m− 3 for Mumbai. The magnitude of reduction in PM1 among different metros is influenced by biofuel usage. A baseline estimate will be a critical input to epidemiologists and health policies. [ABSTRACT FROM AUTHOR]

As a representative of potential "hidden champions", a concept originating in Germany, specialized and innovative Little Giant Enterprises (LGEs) have become exemplary models for small and medium-sized enterprises (SMEs) in China. These enterprises are regarded as crucial support for realizing the strategy of building a strong manufacturing country and addressing the weaknesses in key industrial areas. This paper begins by examining urban agglomerations, which serve as the main spatial carriers for industrial restructuring and high-quality development in manufacturing. Based on data from LGEs in the Yangtze River Delta (YRD) and Pearl River Delta (PRD) urban agglomerations from 2019 to 2023, the study employs the Random Forest (RF) and Multi-scale Geographically Weighted Regression (MGWR) methods to conduct a comparative analysis of their spatial patterns and influencing factors. The results are as follows: (1) LGEs exhibit spatial clustering in both the YRD and PRD regions. Enterprises in the YRD form a "one-axis-three-core" pattern within a distance of 65 km, while enterprises in the PRD present a "single-axis" pattern within a distance of 30 km, with overall high clustering intensity. (2) The YRD is dominated by traditional manufacturing and supplemented by high-tech services. In contrast, the PRD has a balanced development of high-tech manufacturing and services. Enterprises in different industries are generally characterized by a "multi-point clustering" characteristic, of which the YRD displays a multi-patch distribution and the PRD a point–pole distribution. (3) Factors such as industrial structure, industrial platforms, and logistics levels significantly affect enterprise clustering and exhibit scale effects differences between the two urban clusters. Factors such as industrial platforms, logistics levels, and dependence on foreign trade show positive impacts, while government fiscal expenditure shows a negative impact. Natural geographical location factors exhibit opposite effects in the two regions but are not the primary determinants of enterprise distribution. Each region should leverage its own strengths, improve urban coordination and communication mechanisms within the urban cluster, strengthen the coordination and linkage of the manufacturing industry chain upstream and downstream, and promote high-tech industries, thereby enhancing economic resilience and regional competitiveness. [ABSTRACT FROM AUTHOR]

The urban heat island (UHI) phenomenon is negatively impacted by rapid urbanization, which significantly affects people's everyday lives, socioeconomic activities, and the urban thermal environment. This study focuses on the impact of composition, configuration, and landscape patterns on land surface temperature (LST) in Lahore, Pakistan. The study uses Landsat 5-TM and Landsat 8-OLI/TIRS data acquired over the years 2000, 2010 and 2020 to derive detailed information on land use, normalized difference vegetation index, LST, urban cooling islands (UCI), green cooling islands (GCI) and landscape metrics at the class and landscape level such as percentage of the landscape (PLAND), patch density (PD), class area (CA), largest patch index (LPI), number of patches (NP), aggregation index (AI), Landscape Shape Index (LSI), patch richness (PR), and mean patch shape index (SHAPE_MN). The study's results show that from the years 2000 to 2020, the built-up area increased by 17.57%, whereas vacant land, vegetation, and water bodies declined by 03.79%, 13.32% and 0.4% respectively. Furthermore, landscape metrics at the class level (PLAND, LSI, LPI, PD, AI, and NP) show that the landscape of Lahore is becoming increasingly heterogeneous and fragmented over time. The mean LST in the study area exhibited an increasing trend i.e. 18.87°C in 2000, 20.93°C in 2010, and 22.54°C in 2020. The significant contribution of green spaces is vital for reducing the effects of UHI and is highlighted by the fact that the mean LST of impervious surfaces is, on average, roughly 3°C higher than that of urban green spaces. The findings also demonstrate that there is a strong correlation between mean LST and both the amount of green space (which is negative) and impermeable surface (which is positive). The increasing trend of fragmentation and shape complexity highlighted a positive correlation with LST, while all area-related matrices including PLAND, CA and LPI displayed a negative correlation with LST. The mean LST was significantly correlated with the size, complexity of the shape, and aggregation of the patches of impervious surface and green space, although aggregation demonstrated the most constant and robust correlation. The results indicate that to create healthier and more comfortable environments in cities, the configuration and composition of urban impermeable surfaces and green spaces should be important considerations during the landscape planning and urban design processes. [ABSTRACT FROM AUTHOR]

The divergence method, a lightweight approach for estimating emission fluxes from satellite images, rests on a few implicit assumptions. This paper explicitly outlines these assumptions by deriving the method from first principles. The assumptions are: the enhanced mass flux is dominated by advection, normal fluxes vanish at the top and bottom of the atmosphere, steady‐state conditions apply, sources are multiplications of temporal and spatial functions, sinks are described as first‐order reactions, and effective wind fields are concentration‐weighted wind fields. No such assumptions have to be made for the background field. A "topography correction term" does not follow from the theory, but is rather shown to be a practical correction for topography‐dependent effective wind speed errors. The cross‐sectional flux method follows naturally from the derived theory, and the methods are compared. Effects of discrete pixels and finite‐difference operations are explored, leading to recommendations, primarily the recommendation to integrate over small regions only to minimize the influence of noise. Numerical examples featuring Gaussian plumes and COSMO‐GHG simulated plumes are provided. The Gaussian plume example suggests that the divergence method might underestimate emissions when assuming only advection in the presence of cross‐wind diffusion. Conversely, the cross‐sectional flux method remains unaffected, provided fluxes are integrated across the entire plume. The COSMO‐GHG example reveals frequent violations of the steady‐state assumption, although the assumption remains valid proximal to the source (<20 km in this example). It is the hope that this paper provides a solid theoretical foundation for the divergence and cross‐sectional flux methods. Plain Language Summary: Power plants, megacities, and other regions can be places where considerable amounts of gases are emitted into the atmosphere. Satellite data is capable of recording the enhanced concentrations in the atmosphere due to these sources. How does one estimate emissions of these sources based on this data? Typically by running an atmospheric inverse model; but one computationally lightweight method gaining popularity is the "divergence method." With this method, one applies a simple mathematical operation to the satellite image multiplied by the horizontal wind speeds—the result of which is related to the emissions. The method has been used before, but here we systematically state the assumptions involved; factors like how gases are transported horizontally and over time, and what happens when we apply the method on pixelated data (such as satellite images). We find that some other analyses in the literature may be partially incorrect. Another popular method (the "cross‐sectional flux") is easily derived from the same theory. Synthetic examples are used to illustrate that various assumptions are not met in realistic data; although the examples also show that one can work around these limitations by a careful application of the methods, and by acquiring more estimates over many days. Key Points: The divergence method for estimating emissions from satellite images is derived from first principlesAssumptions made on the way are made explicit, highlighting discrepancies with existing literatureA comparison is made against the cross‐sectional flux method which follows from the same theory [ABSTRACT FROM AUTHOR]

Rapid urbanization has resulted in the substantial population growth in metropolitan areas. However, existing research on population change of the cities predominantly draws on grid statistical data at the administrative level, overlooking the intra-urban variegation of population change. Particularly, there is a lack of attention given to the spatio-temporal change of population across different urban forms and functions. This paper therefore fills in the lacuna by clarifying the spatio-temporal characteristics of population growth in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) from 2000 to 2020 through the methods of local climate zone (LCZ) scheme and urban–rural gradients. The results showed that: (1) High population density was observed in the compact high-rise (LCZ 1) areas, with a noticeable decline along urban–rural gradients. (2) The city centers of GBA experienced the most significant population growth, while certain urban fringes and rural areas witnessed significant population shrinkage. (3) The rate of growth tended to slow down after 2010, but the uneven development of population-based urbanization was also noticeable, as urbanization and industrialization varied across different LCZ types and cities in GBA. This paper therefore contributes to a deeper understanding of population change and urbanization by clarifying their spatio-temporal contingences at landscape level. [ABSTRACT FROM AUTHOR]

This study investigates the responses of the urban atmospheric thermal environment to two distinct heat waves in Hefei, China, and explores potential changes associated with future urban expansion. During the Event 1, characterized by clear and dry conditions, the western Pacific subtropical high limits water vapor influx, resulting in a significant cooling effect in rural area due to higher surface latent heat flux. The urban heat island (UHI) intensity, calculated using surface temperature and 2‐m temperature, reaches 5.2°C and 1.7°C during the Event 1, respectively. Although Event 2, characterized by cloudy and humid conditions, exhibits weaker UHI and urban dry island effects, it remains highly unfavorable for human comfort. During distinct heat waves, the vertical extent of the warming effect induced by future urban expansion varies, which can be attributed to environmental factors, such as atmospheric stability and near‐surface wind speed. Plain Language Summary: The study investigates the interactions between the urban atmospheric thermal environment and two distinct heat waves in Hefei, China, as well as the changes induced by future urban expansion. During the first event, which has clear and dry weather conditions, the influx of water vapor is limited by a high‐pressure system. Consequently, rural area experiences a significant cooling effect due to higher surface latent heat flux. The urban heat island (UHI) intensity, measured by surface temperature and 2‐m temperature, reaches 5.2°C and 1.7°C, respectively, during this event. In contrast, the second event, characterized by cloudy and humid weather conditions, exhibits weaker UHI and urban dry island effects but remains highly uncomfortable for humans. The vertical extent of the warming effect caused by future urban expansion varies during distinct heat waves. This variation can be attributed to environmental factors, such as atmospheric stability and near‐surface wind speed. Key Points: The underlying mechanisms of the different responses of the urban atmospheric thermal environment to distinct heat wave events are analyzedThe limitation of water vapor influx by a high‐pressure system and intense solar radiation jointly enhance the urban heat island effectAtmospheric stability and wind speed could influence the vertical extent of the warming effect induced by future urban expansion [ABSTRACT FROM AUTHOR]

This research article explores the valuation of mixed-use developments and their impact on urban planning and city regeneration. The study introduces a Multi-Criteria Decision Making (MCDM) methodology to analyze complex buildings developed in Shanghai from 2009 to 2019. Two MCDM appraisals are offered in different developments using three groups of key indicators that served as benchmarks for other Chinese clusters and global megacities. The article addresses two primary research questions: how mixed-use assets can be assessed using MCDM, and what the key performance indicators and factors contributing to the success of mixed-use developments are. The findings highlight the importance of connectivity, previous real estate experience, ESG strategies, international branding, architectural design, financial metrics, and adaptability of the real estate industry in evaluating mixed-use assets. The study provides insight to stakeholders involved in real estate development, including urban planners, developers, and investors, enabling them to make informed decisions and improve sustainable practices. The research also highlights the importance of considering ESG principles, community benefits, and long-term strategies when assessing mixed-use developments to drive social change and contribute to urban regeneration. [ABSTRACT FROM AUTHOR]

To mitigate the damage from and prepare for disasters, individuals and communities should be involved in the disaster risk reduction efforts. Communicating the risk effectively is the essential step of this involvement. Risk communication is a multidisciplinary field. Disaster managers have to work closely with the media, among other partners, but there is a gap in their understanding of each other's roles. This study aims to explore the process of publishing and broadcasting earthquake information through the experiences of media professionals, to understand how journalists and news organizations function before and after disasters, and to provide evidence to help bridge the gap between disaster managers and/or public health authorities and disaster journalists and/or news organizations., especially in earthquake preparedness. Thirteen in-depth interviews were conducted with editors/journalists from national newspapers and TV channels. A good context for investigating these issues is afforded by the megacity Istanbul and the Turkish media. Turkey is a land of earthquakes. A further strong earthquake is expected to hit in the near future. The findings, which gave valuable hints for better collaboration, are presented according to the focus of the question guide: time of and norms for publishing or broadcasting news or information about earthquakes; content of the news or information; disaster journalism and guidelines. [ABSTRACT FROM AUTHOR]

There have been increasing calls in gentrification studies to examine the geography of gentrification in slums, as little is known about the patterns and processes of slum gentrification, especially in sub-Saharan African cities where slums house over 50% of the urban population. This study explored the spatiotemporal changes in slums in Lagos, Nigeria, between 1984 and 20 on the pattern and drivers of gentrification. Data were collected from 42 slums in Lagos through remote sensing (1984–2020) and a field survey (2020–2021). The study integrated geospatial analysis with quantitative and qualitative analysis to investigate the patterns and drivers of gentrification in Lagos slums. The findings show that between 1984 and 2020, all the sampled slums had undergone gentrification processes, apart from those that were completely cleared. However, many slums continue to have deprived areas as they continue to gentrify. Almost all the slum communities have experienced slum clearance in the past. Additionally, the current and new housing developments in the study have favored middle- to high-income groups, which has led to the displacement of previous slum residents. The study identified slum clearance, fires and floodings, the presence of palaces in the community, the proportion of deprived areas in 1984, government interest in the slum, and the size of the church as drivers of slum gentrification processes in Lagos. Finally, the findings show that the vulnerability of slum dwellers increases with slum gentrification. Therefore, this study recommended developing policies and programs, such as sustainable relocation and low-cost housing, to mitigate the negative consequences of slum gentrification, especially in cities with significant shares of low-income groups. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic precipitated a unique period of social isolation, presenting an unprecedented opportunity to scrutinize the influence of human activities on urban air quality. This study employs ARIMA models to explore the impact of COVID-19 isolation measures on the PM10 and PM2.5 concentrations in a high-altitude Latin American megacity (Bogota, Colombia). Three isolation scenarios were examined: strict (5 months), sectorized (1 months), and flexible (2 months). Our findings indicate that strict isolation measures exert a more pronounced effect on the short-term simulated concentrations of PM10 and PM2.5 (PM10: −47.3%; PM2.5: −54%) compared to the long-term effects (PM10: −29.4%; PM2.5: −28.3%). The ARIMA models suggest that strict isolation measures tend to diminish the persistence of the PM10 and PM2.5 concentrations over time, both in the short and long term. In the short term, strict isolation measures appear to augment the variation in the PM10 and PM2.5 concentrations, with a more substantial increase observed for PM2.5. Conversely, in the long term, these measures seem to reduce the variations in the PM concentrations, indicating a more stable behavior that is less susceptible to abrupt peaks. The differences in the reduction in the PM10 and PM2.5 concentrations between the strict and flexible isolation scenarios were 23.8% and 12.8%, respectively. This research provides valuable insights into the potential for strategic isolation measures to improve the air quality in urban environments. [ABSTRACT FROM AUTHOR]

Several heatwaves (HWs) have been recorded in Egypt in recent years. Some of these HWs were mild, while others were severe and resulted in mortalities and morbidities. On the other hand, air pollution is considered a health issue in Egypt's megacities, especially the capital city, Cairo, and its surroundings, the Greater Cairo (GC) region. In this study, we examine a number of HWs that have hit Egypt in recent years, along with the state of air quality, in terms of PM10, NO2, and O3, during the period of HW incidence, with a focus on the GC region. During the period of study, the frequency, intensity, and duration of HWs have been observed to increase. The total number of recorded HW events was 190, encompassing 376 HW days. The time series of daily mean NO2 showed no correlation with temperature during the months that experienced HWs cases. Conversely, PM10 and O3 concentrations exhibited a similar pattern as that of the daily maximum temperature. This increase in the two pollutant concentrations led to a degradation of the air quality, as demonstrated by the fact that the Air Quality Health Index went from "moderate risk", on normal days, to "high risk" during the HWs. [ABSTRACT FROM AUTHOR]

We present a new method for estimating NOx emissions and effective lifetimes from large cities based on NO2 measurements from the TROPOspheric Monitoring Instrument (TROPOMI) (PAL dataset, May 2018–November 2021). As in previous studies, the estimate is based on the downwind plume evolution for different wind directions separately. The novelty of the presented approach lies in the simultaneous fit of downwind patterns for opposing wind directions, which makes the method far more robust (i.e., less prone to local minima with nonphysically high or low lifetimes) than a single exponential decay fit. In addition, the new method does not require the assumption of a city being a "point source" but also derives the spatial distribution of emissions. The method was successfully applied to 100 cities worldwide on a seasonal scale. Fitted emissions generally agree reasonably with the Emissions Database for Global Atmospheric Research (EDGAR) v6 (R=0.72) and are on average 14 % lower, while estimated uncertainties are still rather large (≈ 30 %–50 %). Lifetimes were found to be rather short (2.44 ± 0.68 h) and show no distinct dependency on season or latitude, which might be a consequence of discarding observations at high solar zenith angles (>65 °). The main limitations of this and similar methods are the underlying assumptions of steady state (meaning constant emissions, wind fields and chemical conditions) within about 100 km downwind from a city, which is probably a simplification that is too strong in order to reach higher accuracies. [ABSTRACT FROM AUTHOR]

This article addresses the class imbalance problem in urban gain modelling (UGM) of Tabriz and Isfahan megacities in Iran by proposing novel cost-sensitive machine learning models, namely costsensitive support vector machine (CSVM), random forest (CRF) and artificial neural network (CANN). Random sampling, a frequently utilized method, fails to effectively tackle this issue by biasing models towards no change samples, which outnumber change samples. The results showed that CRF exhibited the highest accuracy (AUC = 0.560), followed by CANN (AUC = 0.557) and CSVM (AUC = 0.448) in Isfahan. In Tabriz, CRF (AUC = 0.809) and CANN (AUC = 0.818) excelled, outperforming balanced sampling models constructed with ANN, RF and SVM with the AUROC of ANN and RF boosted by 15% and 2% in validation. By emphasizing the significance of addressing class imbalance appropriately, this research highlights the improvement in modelling outcomes achievable through the cost-sensitive models especially in Tabriz case. [ABSTRACT FROM AUTHOR]

The Alborz Mountains are among the areas exhibiting high tectonic and seismic activity in northern Iran. Studying key parameters of tectonic structures, including quantitative analysis and observational studies, in such active regions is essential to identify potential active faults and assess the consequent seismic hazards. This study focuses on seismicity and seismotectonics by analyzing seismic parameters, including b-value, mean seismic activity rate, earthquake recurrence time, seismic moment, and fractal dimension derived from micro and teleseismic data. The b-values vary between 0.6 and 1.1 in the tectonically active parts of the study area, corresponding with the reverse/thrust and strike-slip active faults. Large earthquakes might be prone to occur at 10–25 km depth because both catalogues show low b-values (b < 1.0) concentrations at this depth range. The high fractal dimension (> 1.5), high seismic activity rate, large seismic moment parameters, and its continuously increasing trend. Short recurrence periods (20–50 years) of M 6.5 events also emphasize the high seismic activity and high seismic hazard. On the other hand, the prevalence of low b-values is notably observed in areas encompassing densely populated cities such as Rasht, Lahijan, Amol, Babol, Sari, Behshahr, Gorgan, and the megacity of Tehran. Furthermore, we have identified asperities where the Gorgan Plain, the Khazar, and the Alamutrud Fault Zones are located. These findings emphasize the seismic hazard potential in the identified areas and urban centers within the study area. Therefore, particular attention should be directed towards areas exhibiting low b-values when assessing and mitigating seismic hazards. It underscores the necessity for additional focus on seismic hazard assessment and implementation of mitigation strategies in the Alborz region. [ABSTRACT FROM AUTHOR]

Street quality plays a crucial role in promoting urban development. There is still no consensus on how to quantify human street quality perception on a large scale or explore the relationship between street quality and street composition elements. This study investigates a new approach for evaluating and comparing street quality perception and accessibility in Shanghai and Chengdu, two megacities with distinct geographic characteristics, using street-view images, deep learning, and space syntax. The result indicates significant differences in street quality perception between Shanghai and Chengdu. In Chengdu, there is a curvilinear distribution of the highest positive perceptions along the riverfront space and a radioactive spatial distribution of the highest negative perceptions along the ring road and main roads. Shanghai displays a fragmented cross-aggregation and polycentric distribution of the streets with the highest positive and negative perceptions. Thus, it is reasonable to hypothesize that street quality perception closely correlates with the urban planning and construction process of streets. Moreover, we used multiple linear regression to explain the relationship between street quality perception and street elements. The results show that buildings in Shanghai and trees, pavement, and grass in Chengdu were positively associated with positive perceptions. Walls in both Shanghai and Chengdu show a consistent positive correlation with negative perceptions and a consistent negative correlation with other positive perceptions, and are most likely to contribute to the perception of low street quality. Ceilings were positively associated with negative perceptions in Shanghai but are not the major street elements in Chengdu, while the grass is the opposite of the above results. Our research can provide a cost-effective and rapid solution for large-scale, highly detailed urban street quality perception assessments to inform human-scale urban planning. [ABSTRACT FROM AUTHOR]

(1) Background: As global urbanization accelerates, effective mobility in metropolitan areas becomes crucial. City transportation systems, often congested, have diverse transit modes and numerous access points. Our study focuses on the transportation accessibility of the various districts within Moscow, a city with a population of over 12 million and covering approximately 900 square kilometers. (2) Methods: The city was divided into 2 km-by-2 km squares, and we used both personal and public transportation data. This allowed us to analyze spatiotemporal mobility patterns, calculating travel times and distances between these defined centroids. Our assessment not only considered transportation to key hubs, such as major train stations, airports, and the city center, but also weighed the integral interconnectedness of individual districts. Various time frames, including morning and evening peak hours and quieter weekend periods, were used. (3) Results: The study pinpointed the most and least convenient districts for various transit options across the city. Our findings underscore the intricacies of daily commuting patterns in Moscow, highlighting bottlenecks and areas for potential infrastructure enhancement. (4) Conclusions: Using Moscow's case, we demonstrated the methodology to better understand and improve strategic urban planning and intelligent mobility solutions, aiming to bolster transportation accessibility. [ABSTRACT FROM AUTHOR]

The first part of the article discusses the natural environment of humans and its evolution over the past centuries. It examines the changes that have occurred in just the last 100 years and how they have impacted human habitats. It explores how architects and engineers shaping our settlements have influenced the environment, as well as how the model developed during economic growth affects and presents challenges to our society, particularly regarding the interconnection between climate change and the development of our cities. The second part of the writing addresses the issue of megacities, exploring where the almost endless growth of our metropolises has led, the problems it causes, the differences observed between the growth of megacities in developed and developing countries, the reasons behind it, and the additional difficulties it poses to their residents. [ABSTRACT FROM AUTHOR]

Economic resilience provides a new perspective for megacities to achieve sustainable development when facing multiple shocks, and its accurate evaluation is an essential prerequisite for optimizing urban governance. There are currently no generally accepted methods for empirical evaluation or measuring economic resilience, and the present study aims to contribute to in both the research field and methodology. The present study sets dimensions and indicators based on economic resilience's theoretical and empirical research and used Decision Making Trial and Evaluation Laboratory (DEMATEL) and Interactive Structural Modeling (ISM) methods to exclude the effect indicators and divide the indicator hierarchy, respectively. Subsequently, the present study conducts model validation using Chinese megacities as a case study. The game theory weighting method, which combines the Analytic Hierarchy Process (AHP) and Entropy methods, is used to calculate indicator weights, and the VIKOR (VIseKriterijumska Optimizacija i KOmpromisno Resenje) method is used to evaluate and compare economic resilience of megacities. The research findings indicate that the evaluation model constructed in the present study included 15 indicators (after excluding three effect indicators) divided into four levels. After merging the levels, they correspond to three dimensions: resistance, recoverability, and adaptability. In addition, using Chinese megacities as a case study, the evaluation results found that Beijing, Shanghai, and Shenzhen have high economic resilience, Tianjin and Guangzhou have moderate economic resilience, Chengdu has low economic resilience, and Chongqing has the lowest economic resilience. This result is consistent with previous studies and verifies the model's effectiveness. The present study also found that megacities with lower levels of economic resilience exhibit a more significant upward trend, as well as the highest and higher proportion of economic resilience in Chinese megacities depending on time passes, indicating that megacities' economic resilience is weakening. The evaluation result obtained in the present study is more specific, precise, and focused on depicting the distribution differences and development trends of economic resilience at the urban level. [ABSTRACT FROM AUTHOR]

Severe ozone (O3) pollution has been recorded in China in recent years. The key precursor, volatile organic compounds (VOCs), is still not well understood in Nanning, which is a less developed city compared to other megacities in China. In this study, a year-long measurement of VOCs was conducted from 1 October 2020 to 30 September 2021, to characterize the ambient variations and apportion the source contributions of VOCs. The daily-averaged concentration of VOCs was measured to be 26.4 ppb, ranging from 3.2 ppb to 136.2 ppb across the whole year. Alkanes and oxygenated VOCs (OVOCs) were major species, contributing 46.9% and 25.2% of total VOC concentrations, respectively. Propane, ethane, and ethanol were the most abundant in Nanning, which differed from the other significant species, such as toluene (3.7 ppb) in Guangzhou, ethylene (3.8 ppb) in Nanjing, and isopentane (5.5 ppb), in Chengdu. The positive matrix factorization (PMF) model resolved six source factors, including vehicular emission (contributing 33% of total VOCs), NG and LPG combustion (19%), fuel burning (17%), solvent use (16%), industry emission (10%), and biogenic emission (5%). This indicated that Nanning was less affected by industrial emission compared with other megacities of China, with industry contributing 12–50%. Ethylene, m/p-xylene, butane, propylene, and isoprene were key species determined by ozone formation potential (OFP) analysis, which should be priority-controlled. The variations in estimated OFP and observed O3 concentrations were significantly different, suggesting that VOC reactivity-based strategies as well as meteorological and NOx effects should be considered collectively in controlling O3 pollution. This study presents a year-long dataset of VOC measurements in Nanning, which gives valuable implications for VOC control in terms of key sources and reactive species and is also beneficial to the formulation of effective ozone control strategies in other less developed regions of China. [ABSTRACT FROM AUTHOR]

The Aethalometer is a widely used instrument for black carbon (BC) mass concentration and light absorption coefficient (babs) measurements around the world. However, field intercomparison of the two popular models, dual-spot (AE33) and single-spot (AE31) Aethalometers, remains limited; in addition, the difference in secondary brown carbon (BrCsec) light absorption estimation between the two models is largely unknown. We performed full-year collocated AE33 and AE31 measurements in a megacity in southern China – Guangzhou. The babs values agree well between the two Aethalometers (R2 > 0.95), with AE33 / AE31 slopes ranging from 0.87 to 1.04 for seven wavelengths. AE33 consistently exhibits lower limits of detection (LODs) than AE31 for time resolutions of 2 to 60 min. The AE33 / AE31 slope for equivalent BC (eBC) was 1.2, implying the need for site-specific post-correction. The absorption Ångström exponent (AAE) obtained from different approaches does not agree very well between the two models, with the biggest discrepancy found in AAE880/950. The estimated BrCsec light absorption at 370 nm (babs370_BrCsec) was calculated using the minimum- R -squared (MRS) method for both Aethalometers. The babs370_BrCsec comparison yields a slope of 0.78 and an R2 of 0.72 between the two models, implying a non-negligible inter-instrument difference. This study highlights the high consistency in babs but less so in AAE between AE31 and AE33 and reveals site-specific correction for eBC estimation and non-negligible difference in BrCsec estimation. The results are valuable for data continuity in long-term Aethalometer measurements when transitioning from the older (AE31) to the newer (AE33) model, as anticipated in permanent global-climate and air-quality stations. [ABSTRACT FROM AUTHOR]

This paper argues for normative visioning as an underdeveloped component of adaptation planning. Multi-stakeholder and normative approaches to future visioning offer generative moments when creativity can meet the power to act required for critical, including transformative, adaptation. Including normative methods with community and city actors in adaptation planning allows for alternative narratives of development to arise as a basis for deeper conversation and potential action on the root causes of vulnerability and risk. A specific visioning approach is tested for four megacities – Istanbul, Kathmandu, Nairobi and Quito. Relations between current and future states of development and resilience are found to be both aligned (congruent or contingent) and in opposition (countervailing or constrained) shaping strategy for policy setting. These data are combined with additional work from London, Kolkata, New York and Lagos to pilot a City Resilience Challenge Index (CRCI), indicating to policy-makers whether and how cities are currently moving away from, rather than towards, envisioned trajectories of vulnerability reduction and adaptation. In the future, the CRCI might provide a global tool to track the progress of cities towards climate resilient development and, by doing so, to increase ambition and galvanize action. [ABSTRACT FROM AUTHOR]