Abstract The abysmal state of and challenges in municipal solid waste management (MSWM) in urban India is the motivation of the present study. Urbanization contributes enhanced municipal solid waste (MSW) generation and unscientific handling of MSW degrades the urban environment and causes health hazards. In this paper, an attempt is made to evaluate the major parameters of MSWM, in addition to a comprehensive review of MSW generation, its characterization, collection, and treatment options as practiced in India. The current status of MSWM in Indian states and important cities of India is also reported. The essential conditions for harnessing optimal benefits from the possibilities for public private partnership and challenges thereof and unnoticeable role of rag-pickers are also discussed. The study concludes that installation of decentralized solid waste processing units in metropolitan cities/towns and development of formal recycling industry sector is the need of the hour in developing countries like India.
Cesar I. N. Sampaio Filho, Humberto A. Carmona, Antonio S. Lima Neto
et al.
Urban scaling theory posits that urban indicators follow power-law relations with population, yet the evolution of these patterns - and the role of regional differences in settings marked by social inequalities and unplanned urbanization - remains poorly understood. Here, we analyze nearly three decades of mortality data from Brazilian cities to investigate the scaling of external causes of death: homicides, suicides, and accidents. Using a hierarchical Bayesian framework and spatial correlation analysis, we find that these mortality indicators exhibit distinct, regionally heterogeneous scaling trajectories. Homicide mortality has significantly attenuated its typical superlinear scaling with increased spatial clustering, suggesting a redistribution of violence to smaller cities and intensified intercity interactions, possibly linked to the consolidation of organized crime. Suicide mortality, usually sublinear, has trended upward, implying a weakening of urban agglomerations' protective effect. Accident mortality remains superlinear, with transport fatalities scaling nearly proportionally, and non-transport accidents becoming superlinear. The scaling changes for suicides and accidents coincide with less correlated and stable spatial patterns, suggesting that the underlying processes predominantly operate within city boundaries. Finally, while scaling exponents have evolved more homogeneously across Brazilian states, scale-adjusted mortality remains highly heterogeneous, indicating that fundamental processes govern scaling laws, whereas state-specific factors drive scale-adjusted metrics.
Abstract Nature-based Solutions (NbS) are vital for achieving sustainable urban development. While urban tree planting is one of the most important approaches to enhance NbS, current practices often concentrate on tree quantity or green coverage targets. NbS planning studies are also limited to priority identification, revealing a notable gap in both study and practice. This study presents a tree species composition optimization-based framework for maximizing regional NbS by linking local demands and the effectiveness of tree species through a multi-objective optimization algorithm. A case study was designed in Philadelphia, and the optimal tree species composition was explored on 0.25 km2 grids. The spatial heterogeneity of local demands and the varying effectiveness of tree species highlight the significance of strategic tree placement. The current tree species composition in Philadelphia is suboptimal for achieving NbS. Future greening efforts should increase the proportion of advantageous species, such as Acer saccharinum, Acer rubrum, and Liquidambar styraciflua. Compared with the baseline, the optimized species composition can provide substantially greater ecosystem services, for instance, about 20% more in stormwater management and up to 80% more in microclimate regulation. Two general planning recommendations are proposed: (1) maximize carbon sequestration capacity in areas with insignificant urban hazards; and (2) strategically place trees with specific advantages in targeted response to specific urban hazards. The developed framework provides guidance for efficient urban greening projects, enabling maximization of NbS under given greening quantity targets.
This study investigates the complex dynamics of new-type urbanization in resource-based county-level cities, using Wuan City in Hebei Province, China, as a representative case. As China pursues a high-quality development agenda, cities historically dependent on resource extraction face profound challenges in achieving sustainable and inclusive urban growth. This research employs a multi-method approach—including Theil index analysis, industrial shift-share analysis, a Cobb–Douglas production function model, and a composite urbanization index—to quantitatively diagnose the constraints on Wuan’s development and assess its transformation efforts. Our empirical results reveal a multifaceted situation: while the urban–rural income gap has narrowed, rural income streams remain fragile. The shift-share analysis indicates that although Wuan’s traditional industries have regained competitiveness, the city’s economic structure is still burdened by a persistent negative structural component, hindering diversification. Furthermore, the economy exhibits characteristics of a labor-intensive growth model with inefficient capital deployment. These underlying issues are reflected in a comprehensive urbanization index that, after a period of rapid growth, has recently stagnated, signaling the exhaustion of the city’s traditional development mode. In response, Wuan attempts an “industrial transformation-driven new-type urbanization” path. This study details the three core strategies being implemented: (1) incremental population urbanization through development at the urban fringe and in industrial zones; (2) in situ urbanization of the existing rural population; and (3) the cultivation of specialized “characteristic small towns” to create new, diversified economic nodes. The findings from Wuan offer critical, actionable lessons for other resource-dependent regions. The case demonstrates that successful urban transformation requires not only industrial upgrading but also integrated, spatially aware planning and robust institutional support. We conclude that while Wuan’s model provides a valuable reference, its strategies must be adapted to local contexts, emphasizing the universal importance of institutional innovation, human capital investment, and a people-centered approach to achieving resilient and high-quality urbanization.
An increasing number of modernist churches of the Evangelical Lutheran Church of Finland which were built in the 1960s and 1970s are reaching a point in their life cycle where they require extensive renovations or demolition. As church membership is falling due to secularisation, an ageing population, and immigration, the financial resources to do extensive renovations are also diminishing. Hence more and more modernist churches are threatened by demolition. Despite their relatively young age, these churches have already become meaningful for and entwined with the lives of local communities, and their removal is felt as a loss of valuable heritage. This article discusses the reasons for demolition and analyses subsequent debates in the public media. While most media attention is directed to values defined by architects and heritage professionals, the emotional and autobiographical values of the locals are less appreciated. It is argued that heritage professionals could prepare for the demolitions by adopting the framework of anticipatory grief, which acknowledges and perhaps alleviates the loss felt by the stakeholders.
Aesthetics of cities. City planning and beautifying, Urban groups. The city. Urban sociology
The notion of the $x$-minute city is again popular in urban planning, but the practical implications of developing walkable neighborhoods have not been rigorously explored. What is the scale of the challenge that cities needing to retrofit face? Where should new stores or amenities be located? For 500 cities in the United States, we explored how many additional supermarkets would be required to achieve various levels of $x$-minute access and where new stores should be located so that this access is equally-distributed. Our method is unique because it combines a novel measure of equality with a new model that optimally locates amenities for inequality-minimizing community access. We found that 25% of the studied cities could reach 15-minute access by adding five or fewer stores, while only 10% of the cities could even achieve 5-minute average access when using neighborhood centroids as potential sites; the cities that could, on average, required more than 100 stores each. This work provides a tool for cities to use evidenced-based planning to efficiently retrofit in order to enable active transport, benefiting both the climate and their residents' health. It also highlights the major challenge facing our cities due to the existing and ongoing car-dependent urban design that renders these goals unfeasible.
3D multimodal question answering (MQA) plays a crucial role in scene understanding by enabling intelligent agents to comprehend their surroundings in 3D environments. While existing research has primarily focused on indoor household tasks and outdoor roadside autonomous driving tasks, there has been limited exploration of city-level scene understanding tasks. Furthermore, existing research faces challenges in understanding city scenes, due to the absence of spatial semantic information and human-environment interaction information at the city level.To address these challenges, we investigate 3D MQA from both dataset and method perspectives. From the dataset perspective, we introduce a novel 3D MQA dataset named City-3DQA for city-level scene understanding, which is the first dataset to incorporate scene semantic and human-environment interactive tasks within the city. From the method perspective, we propose a Scene graph enhanced City-level Understanding method (Sg-CityU), which utilizes the scene graph to introduce the spatial semantic. A new benchmark is reported and our proposed Sg-CityU achieves accuracy of 63.94 % and 63.76 % in different settings of City-3DQA. Compared to indoor 3D MQA methods and zero-shot using advanced large language models (LLMs), Sg-CityU demonstrates state-of-the-art (SOTA) performance in robustness and generalization.
Abstract As a hot area of population inflow in the process of urbanization, the urban expansion area faces rapid growth of surface urban heat island (SUHI). However, the multi-dimensional evolutionary characteristics of SUHI in urban expansion areas are still unclear. Through analyzing the evolution of SUHI range ratio, mean intensity and maximum intensity, in this study we identified the comprehensive evolutionary pattern of summer SUHI in urban expansion areas of 31 major cities in China during 2000–2018, and further investigated the corresponding dominant influencing factors. The results showed that the SUHI range and intensity in urban expansion areas exhibited a significant increasing trend in 81% and 71% of the cities respectively during the summer daytime. The cities with declining SUHI range and intensity were distributed in northwestern high-altitude areas with low economic level, while the cities with dominant increases in the SUHI range were distributed in eastern low-altitude areas with high economic level. Climate conditions and population distribution were the dominant influencing factors of intensity-dominated increasing and balanced increasing types, respectively. The intensity and range two-dimensional increasing type had experienced the most severe SUHI growth, with large proportion of secondary industry as the main influencing factor. This study highlighted the importance of multi-dimensional characteristics of SUHI evolution, which provided a new insight to understand SUHI change in urban expansion areas and associated mitigation measures.
Urban livability, a concept integral to human settlements, lacks a universally agreed-upon definition. It encompasses various aspects influencing the attractiveness and quality of life in a city. The research adopts an objective evaluation method, focusing on equitable access to urban services. The study aims to address these challenges by examining the livability of Tehran's 22 districts, emphasizing access to essential services. Employing a comprehensive methodology, the research utilizes analytical tools such as Standard Deviational Ellipse analysis (SDE), Average Nearest Neighbor (ANN), and the Multi-Attributive Border Approximation area Comparison (MABAC) technique. The spatial distribution analysis of urban land uses in Tehran reveals distinct patterns through Standard Deviational Ellipse analysis. Urban land uses exhibit directional orientations and concentrations, providing valuable insights for urban planning. Average Nearest Neighbor analysis indicates clustered distribution across various land uses, emphasizing the need for targeted interventions. The study ranks Tehran's districts based on livability using MABAC technique. District 21 emerges as the most livable, while District 10 faces challenges in service distribution. The findings highlight disparities and call for focused urban planning to enhance overall livability in Tehran, recognizing the importance of equitable access to urban services for a sustainable and cohesive urban environment.
Urbanization. City and country, Political institutions and public administration (General)
Carmen IR Fróes-Asmus, Nataly Damasceno, Arnaldo Prata-Barbosa
et al.
Background: Brazil is the largest country in South and Latin America with an accelerated urbanization process, and the city of Rio de Janeiro is the second most populous. The PIPA Cohort Project is the first prospective study investigating the effects of urban exposure to multiple pollutants on maternal–child health in Brazil. Objective: This paper describes the relationship between maternal socio-environmental conditions and newborns’ umbilical cord blood concentrations of metals (lead, arsenic, and mercury). Methods: The study population was a convenience sample of all babies born at the UFRJ Maternity Hospital over a period of 12 months from pregnant women aged 16 or older living in Rio de Janeiro. Demographic, socio-economic, lifestyle, work, and housing variables were collected. Metals concentrations were analyzed in umbilical cord blood using the inductively coupled plasma mass spectrometry technique. Results: There were 844 (93%) eligible births, with 778 (94%) cord blood samples collected. The detection rate of Pb, Hg, and As were 99% (742), 94.5% (708), and 61% (450), respectively. The total green area percentage (PAGT) of urban residence zones was one primary socio-environmental characteristic determinant of high metal exposure (≥median). Newborns living in city zones with lower total green area percentages (PAGT) had equal to or above-median cord blood concentrations of at least one metal (p = 0.026), of lead and mercury (PbHg) at the same time (p = 0.006), or of lead (p = 0.006). The city zones with the worst indicators of greenspace availability also presented human development indexes (HDI) under the city’s mean HDI. Conclusion: The study provides evidence that the lower availability of urban green spaces in residential zones is associated with greater environmental exposure to pollutants (metals) during pregnancy and can constitute a socio-environmental vulnerability indicator.
Infectious and parasitic diseases, Public aspects of medicine
This article’s main objectives are to characterize the logics that underlie governance framed within the post-human paradigm, to emphasize the risks of this type of governance and to mention the organizational principles for alternative governance. The text’s approach takes as its central issue the development of automation technologies and the internet of things and their applications in society and the environment. Given the political and economic logics of current globalization, the need for participatory and representative citizenship at different levels of political decision-making is defended, including in matters of sharing and transmission of scientific-technological knowledge.
Aesthetics of cities. City planning and beautifying, Urban groups. The city. Urban sociology
Anthropogenic heat intensity arises from levels of population, buildings and vehicle densities. Population and built-up densities are very high in the cities of developing countries, which may have an impact on heat generated from metabolism and buildings differently compared to developed countries. Hence, this study investigated the magnitude of anthropogenic heat in different land uses and areas with different built-up densities pertaining to Indian metropolises; Bengaluru metropolitan area was selected for this study. The maximum metabolic heat (22.8 W/m2), vehicular heat (87.2 W/m2) and building heat (443.0 W/m2) were found in the high-density residential grids and the mixed-use grids in the city centre area during 2017. The lowest value (0.1 W/m2) was found in the low-density residential areas, public and semi-public areas, restricted areas and agricultural areas. A high positive correlation value (0.8 in 2011 and 0.72 in 2017) was found between non-residential building surface fractions and anthropogenic heat.
Modeling and designing urban building layouts is of significant interest in computer vision, computer graphics, and urban applications. A building layout consists of a set of buildings in city blocks defined by a network of roads. We observe that building layouts are discrete structures, consisting of multiple rows of buildings of various shapes, and are amenable to skeletonization for mapping arbitrary city block shapes to a canonical form. Hence, we propose a fully automatic approach to building layout generation using graph attention networks. Our method generates realistic urban layouts given arbitrary road networks, and enables conditional generation based on learned priors. Our results, including user study, demonstrate superior performance as compared to prior layout generation networks, support arbitrary city block and varying building shapes as demonstrated by generating layouts for 28 large cities.
Nathan Kammoun, Lakmal Meegahapola, Daniel Gatica-Perez
Understanding the social context of eating is crucial for promoting healthy eating behaviors. Multimodal smartphone sensor data could provide valuable insights into eating behavior, particularly in mobile food diaries and mobile health apps. However, research on the social context of eating with smartphone sensor data is limited, despite extensive studies in nutrition and behavioral science. Moreover, the impact of country differences on the social context of eating, as measured by multimodal phone sensor data and self-reports, remains under-explored. To address this research gap, our study focuses on a dataset of approximately 24K self-reports on eating events provided by 678 college students in eight countries to investigate the country diversity that emerges from smartphone sensors during eating events for different social contexts (alone or with others). Our analysis revealed that while some smartphone usage features during eating events were similar across countries, others exhibited unique trends in each country. We further studied how user and country-specific factors impact social context inference by developing machine learning models with population-level (non-personalized) and hybrid (partially personalized) experimental setups. We showed that models based on the hybrid approach achieve AUC scores up to 0.75 with XGBoost models. These findings emphasize the importance of considering country differences in building and deploying machine learning models to minimize biases and improve generalization across different populations.
The Egyptian cities' urban renewal movement has succeeded in enhancing the planning of road and vehicle bridge networks. Bridges are frequently recognized as a symbol of a city's economic potential and prosperity, but the disappearance of green features is considered one of the negatives, particularly after the construction of many bridges and the consequent difficulties faced by pedestrians. Because the visual quality of bridge experiences might influence on urban sustainability, biophilic urbanism that has arisen to incorporate nature more purposefully into cities. Adding visual value (using bridge sidewalks) and creating more enjoyable spaces can solve many urban space informality issues while preserving the city's visual and aesthetic elements. As a result, the research aims to develop a green approach for building walkable green bridges over these car bridges to connect the vertical and horizontal green elements together, revitalizing the city's green image. From this point of view, this paper focuses on two main issues: first, the theoretical approach, which will focus on the biophilic urban design and the benefits of integration with the urban design of streets based on environmental, social, and economic functions. Secondly: the evaluation and analysis of the area in Egypt (Nasr City) to reduce the impact of climate change by applying a balance between green and built spaces to upgrade urban streets. Based on the theoretical and applied approaches, the research proposes a green framework for the design of green biophilic pedestrian bridges to be a link between vertical and horizontal green elements to achieve sustainability.
نجحت حركة التطور العمراني التي تشهدها المدن المصرية في تطوير تخطيط شبكات الطرق وجسور المركبات وتعتبر هذه الجسور رمزا للإمكانيات الاقتصادية في المدينة وازدهارها. لكن اختفاء العناصر الخضراء يعتبر أحد السلبيات خاصة بعد بناء العديد من الجسور وما يترتب على ذلك من صعوبات يواجهها المشاة. ونظرًا لأن جودة الصورة البصرية المرئية للجسور تؤثر على الاستدامة الحضرية، فهذا يستدعي انتهاج مبدأ العمران البيوفيليكي لدمج الطبيعة بشكل هادف مع المدن، ويتضمن ذلك إدخالها في المدن وإليها ، وكذلك داخل المباني والبنية التحتية وفيما بينها ، لتعزيز الاتصال بين الناس والبيئة مع الاستفادة أيضًا من الخدمات والوظائف الطبيعية. إن إضافة قيمة بصرية (باستخدام أرصفة وجوانب الجسور) وايجاد المزيد من الفراغات والأنشطة الممتعة تؤدي إلى حل العديد من المشكلات والقضايا في المناطق العمرانية مع الحفاظ على الصورة المرئية للمدينة والعناصر الجمالية. ونتيجة لذلك فإن الهدف من البحث هو ايجاد منهجية خضراء لإنشاء جسور خضراء قابلة للمشي فوق جسور السيارات هذه لربط العناصر الخضراء الرأسية والأفقية معًا، وتنشيط الصورة الخضراء للمدينة والتغلب على الصعوبات التي يواجهها المشاة. من هذا المنطلق تركز هذه الورقة على مدخلين رئيسيين: أولا المدخل النظري الذي سيركز على التصميم الحضري الحيوي البيوفيليكي، وفوائد التكامل مع التصميم الحضري للشوارع على أساس الوظائف البيئية والاجتماعية والاقتصادية. ثانيًا: المدخل التطبيقي ويتناول تقييم وتحليل منطقة من أهم المناطق العمرانية في مصر (مدينة نصر) للحد من تأثير التغير المناخي من خلال تطبيق التوازن بين المساحات الخضراء والمساحات المبنية لتطوير الطرق والفراغات العمرانية. واستنادا على المنهجين النظري والتطبيقي، يقترح البحث إطارًا أخضر لتصميم جسور المشاة الخضراء الحيوية لتكون رابطًا بين العناصر الخضراء الرأسية والأفقية لدمج الطبيعة في التصميم الحضري للمدن وربط الإنسان بالطبيعة لتحقيق الاستدامة .
Cities. Urban geography, Urbanization. City and country
Rapid population growth and climate change drive urban renewal and urbanization at massive scales. New computational methods are needed to better support urban designers in developing sustainable, resilient, and livable urban environments. Urban design space exploration and multi-objective optimization of masterplans can be used to expedite planning while achieving better design outcomes by incorporating generative parametric modeling considering different stakeholder requirements and simulation-based performance feedback. However, a lack of generalizable and integrative methods for urban form generation that can be coupled with simulation and various design performance analysis constrain the extensibility of workflows. This research introduces an implementation of a tensor-field-based generative urban modeling toolkit that facilitates rapid design space exploration and multi-objective optimization by integrating with Rhino/Grasshopper ecosystem and its urban analysis and environmental performance simulation tools. Our tensor-field modeling method provides users with a generalized way to encode contextual constraints such as waterfront edges, terrain, view-axis, existing streets, landmarks, and non-geometric design inputs such as network directionality, desired densities of streets, amenities, buildings, and people as forces that modelers can weigh. This allows users to generate many, diverse urban fabric configurations that resemble real-world cities with very few model inputs. We present a case study to demonstrate the proposed framework's flexibility and applicability and show how modelers can identify design and environmental performance synergies that would be hard to find otherwise
Americans travel 7 to 9 miles on average for shopping and recreational activities, which is far longer than the 15-minute (walking) city advocated by ecologically-oriented urban planners. This paper provides a comprehensive analysis of local trip behavior in US cities using GPS data on individual trips from 40 million mobile devices. We define local usage as the share of trips made within 15-minutes walking distance from home, and find that the median US city resident makes only 12% of their daily trips within such a short distance. We find that differences in access to local services can explain eighty percent of the variation in 15-minute usage across metropolitan areas and 74 percent of the variation in usage within metropolitan areas. Differences in historic zoning permissiveness within New York suggest a causal link between access and usage, and that less restrictive zoning rules, such as permitting more mixed-use development, would lead to shorter travel times. Finally, we document a strong correlation between local usage and experienced segregation for poorer, but not richer, urbanites, which suggests that 15-minute cities may also exacerbate the social isolation of marginalized communities.
Keith Burghardt, Johannes H. Uhl, Kristina Lerman
et al.
The scaling relations between city attributes and population are emergent and ubiquitous aspects of urban growth. Quantifying these relations and understanding their theoretical foundation, however, is difficult due to the challenge of defining city boundaries and a lack of historical data to study city dynamics over time and space. To address this issue, we analyze scaling between city infrastructure and population across 857 United States metropolitan areas over an unprecedented 115 years using dasymetrically refined historical population estimates, historical urban road network models, and multi-temporal settlement data to define dynamic city boundaries based on settlement density. We demonstrate the clearest evidence that urban scaling exponents can closely match theoretical models over a century if cities are defined as dense settlement patches. Despite the close quantitative agreement with theory, the empirical scaling relations unexpectedly vary across regions. Our analysis of scaling coefficients, meanwhile, reveals that a city in 2015 uses more developed land and kilometers of road than a city with a similar population in 1900, which has serious implications for urban development and impacts on the local environment. Overall, our results offer a new way to study urban systems based on novel, geohistorical data.