Challenge For Cities Research Articles

Reimagining urban waste management: Addressing social, climate, and resource challenges in modern cities

Governments worldwide are seeking better solutions for solid waste management. Thermal treatment projects are presented as quick fixes for rising waste challenges, without addressing the limitations of incineration. Currently, there is a rise in proposals for thermal treatment technologies in developing countries. Scrutiny of the risks and impacts of these alternatives is necessary due to social, climate, and resource considerations. Energy from waste incineration is considered fossil energy since about half of the CO2 emissions come from fossil polymers in the waste. From a sustainability perspective, landfilling is a short-term option for materials currently unsuitable for recycling. Landfills act as bioreactors, producing valuable biogas, and serve as “resource banks,” storing unrecyclable resources until better recycling techniques are developed. In developing countries manual labor is abundant and material sorting and landfilling are more valuable and have a lower climate and resource footprint. This paper offers a novel, integrated perspective of waste management in view of poverty reduction, climate change and resource conservation.

Innovative Circular Biowaste Valorisation—State of the Art and Guidance for Cities and Regions

The management of the organic fraction of municipal solid waste (OFMSW), also called urban biowaste, and urban wastewater sludge (UWWS) represents a challenge for cities and regions, which want to adopt innovative urban bioeconomy approaches for their treatment and production of high-added-value products beyond the traditional anaerobic digestion (AD) and compost. This adoption is often restricted by the availability and maturity of technologies. The research object of this manuscript, based on the findings of EU Horizon 2020 project HOOP, is the identification of state-of-the-art circular technologies for material valorisation of OFMSW and UWWS, following a novel screening methodology based on the scale of implementation (tested at least at pilot scale). The screening resulted in 25 technologies, which have been compared and discussed under a multidisciplinary assessment approach, showing their enabling factors and challenges, their current or potential commercial status and their compatibility with the traditional technologies for urban biowaste treatment (composting and AD). The bioproducts cover market sectors such as agriculture, chemistry, nutrition, bioplastics, materials or cosmetics. Therefore, the results of this review help project promoters at city/region level to select innovative technologies for the conversion of OFMWS and UWWS into high value products.

Municipal Solid Waste Management System: A Study of Aligarh City, Uttar Pradesh, India

Municipal solid waste management (MSWM) is a significant environmental challenge in Indian cities, including Aligarh. Inadequate handling of municipal solid waste (MSW) poses risks to public health and the environment. Studies indicate that approximately 90% of MSW in India is improperly disposed of in open dumps and landfills, leading to various ecological and health issues. A detailed examination of Aligarh's waste management system was conducted to assess the quantity, characteristics, and sustainable management options for its municipal waste. Findings from the study show that private collectors handle about 430 tons of waste per day in Aligarh, but neither residents nor collectors engage in waste segregation at the source. The combined collection efficiency of A2Z Private Limited and the Aligarh Municipal Corporation is estimated to be around 70%. Due to the high organic content in the waste, its energy potential remains untapped. Currently, about 80% of the collected waste is disposed of in open dumps, as Aligarh lacks a sanitary landfill. This study highlights the current state of municipal solid waste management in Aligarh focusing on the quantity, quality, and management strategies in Aligarh. Methodology: For this study, Aligarh, a medium-sized city with a population of roughly 8.7 lakhs, which is located 130 kilometres from Delhi, India's capital, was chosen. A thorough assessment of the literature was done to create a theoretical framework. Visits to fields were carried out to gather basic data and comprehend the city's SWMS, including interaction During interviews with several municipality employees and executives in charge of SWM and citizens of the city. A procedure was created to examine the sources, calculate the amounts, and ascertain the waste streams' makeup. Findings: Despite their best efforts, the local municipality's limited resources do not allow for the effectiveness of the solid waste management system in Aligarh. On the outskirts of the city, waste is frequently disposed of in open or low-lying regions without using the correct scientific or engineering techniques.

Noise without noise? Art interventions in a Southeast Asian city

The experimental music community Jogja Noise Bombing based in the Indonesian city of Yogyakarta has for more than a decade experimented with pop-up performances of harsh noise played on DIY instruments in urban spaces. These urban spaces, however, tend themselves to be very "noisy". Since 2018 we have followed these performances online and through fieldwork in Indonesia with an ongoing curiosity that stays with the trouble of noise. We are attracted to the context of these performances because they challenge us to answer a series of paradoxical questions: what is noise aesthetics in a place where everything is "noisy" and where this noisiness, furthermore, does not seem to be experienced as a problem or provocation? Can one even speak of "noise" if it is not unwanted? The social aesthetics of Indonesian harsh noise music in its specific attunement to the soundscapes of the Indonesian city challenges Western conventional ontologies of noise and ideas of the relationship between "objective" noise and aesthetic performances of noise such as noise music in several ways.

Cartographies of infrastructural imaginations: mapping ecological utopias and dystopias in the Global South

This article provides the reader with a theoretical framework and a method of representing cities called cartographies of infrastructural imaginations. The study employs mapping methods from the fields of architecture, urban geography and visual cultures. The research inquires about the role of cartography in the analysis of discourses that define policies of water supply, food distribution and land-use regulation, which are three environmental challenges in cities. How can we identify and situate the urban actors that attend to such challenges in cities from the Global South? The research is empirically grounded in Mexico City, Shanghai and Bangalore, urban settlements with a history of colonial occupation in previous centuries. Their foreign interventions still shape urban imaginaries of these cities. The method of blending photographic analysis with maps aims to offer objective precision of geographical data and subjective street-level views of local stories. The intention is to understand where the infrastructural ideas come from, and how imaginaries flow to communicate visions about the development of the city. A central task here is to frame how power structures interact and represent their interests via utopian and dystopian narratives.

Ride-Hailing vs. Fixed-Route: Preferences of the Transit-Dependent Populations in U.S. Urbanized Areas

Transportation inequality poses significant challenges in car-dependent cities in the US, especially for Transit-Dependent Populations (TDPs) who rely on public transportation to meet their travel requirements. Research indicates that despite the rapid growth of ride-hailing services like Uber, TDPs primarily depend on conventional transit options such as buses and metros. This study differentiates between two classifications of ride-hailing services: Private Ride-hailing (PRH), represented by platforms like Uber and Lyft, where individuals hire and pay for their rides, occasionally sharing the journey with guests; and ride-sharing (RS), like UberPool, which allows users to divide travel expenses. However, a more profound comprehension is necessary to clarify why TDPs show a preference for one mode of transportation over another and the factors that influence their decision-making. This study utilises Structural Equation Modelling (SEM) to examine the direct and indirect relationships between explanatory and outcome variables, while investigating modal preferences and usage frequency in 48 densely populated urban areas in the US (N = 384). TDPs choose to use transportation services like Uber because of their effectiveness in reducing both travel and waiting time, in contrast to traditional Fixed-Route Transit Services (FRTS), which are relatively less efficient. TDPs’ inclination towards PRH leads to a greater dependence on ride-hailing services, whereas a preference for FRTS reduces this dependence. Significantly, the study demonstrates that TDPs’ modal preferences are not only influenced by their socioeconomic status or rational decision-making, but also by the complex interaction between these factors. These findings provide valuable information for policymakers who want to evaluate the sustainability of ride-hailing services for TDPs and effectively tackle transportation inequalities.

Editorial: Desarrollo urbano y energía en el contexto de ciudades intermedias sostenibles

Sustainability-oriented urbanism proposes strategies to address environmental, social, and economic challenges in intermediate cities. Within the framework of the Sustainable Development Goals (SDGs), this issue of CienciAmérica highlights the importance of sustainability in cities. The energy transition of cities is necessary and represents an opportunity to promote sustainable investments, in line with SDG 7 (affordable and clean energy) and SDG 13 (climate action). Similarly, sustainable urban planning, in line with SDG 11 (sustainable cities and communities), promotes the circular economy through proper waste management, thereby reducing environmental impacts and promoting economic sectors and job creation. On the other hand, education for a culture of sustainability, in line with SDG 4 (Quality Education), is essential to create a society that is aware and proactive in protecting the environment. This volume also includes sustainable technology, innovation and economic competitiveness, key aspects in the implementation of SDG 9 (Industry, Innovation and Infrastructure). Finally, this edition calls on governments, businesses, organizations and citizens to work together to build a sustainable future, where sustainability and the economy are intrinsically linked to ensure the sustainable functioning of cities.

Internet of Things (IoT) Driven Water Management System for Efficient Level Control

Water is an essential and valuable resource in daily life, making its conservation crucial to prevent adverse effects. Storing water for domestic, industrial, agricultural, and other purposes is particularly important. Safe drinking water is increasingly becoming polluted due to the growing population and their demands for urbanization and industrialization. At the household level, some people leave electric water pumps running and either go to work or sleep, forgetting to turn off the pumps when the water container is full. This highlights the need for a reliable and continuous water supply. IoT plays a significant role in environmental monitoring, particularly in disaster management, early warning systems, and environmental data analytics. One major challenge in urban cities is water management, especially with the rapid growth of urbanization, necessitating sustainable urban development plans. To address these issues, we propose a "Water Level Monitoring System" solution. This paper presents an IoT-based water monitoring system for real-time applications. The system's sensors measure the water level in the tank, and the data is sent to a cloud server, allowing users to view it on a remote dashboard. This system can be used efficiently by both homeowners and industrial users, as well as other water utilities.

Assessing multiple ecosystem services in 708 European urban areas

ABSTRACT Nature is increasingly recognized for its potential to address societal challenges in cities, through the delivery of ecosystem services (ES). However, large-scale assessments quantifying this potential are rare. In this study, we modelled five ES (local temperature regulation, flood control, global climate regulation, habitat maintenance, and human interaction with nature) across 708 European urban areas. Using a supply-demand approach, we assessed ES delivery: the extent to which ES supply was sufficient to meet the corresponding societal demands. We found that ES delivery varied both spatially and between ES. On average, nearly 50% of the demand was fulfilled, with the highest values for habitat maintenance (81 ± 15%; mean ± SD), flood control (65 ± 13%), and human interaction with nature (59 ± 15%) and much lower values for local temperature regulation (23 ± 28%) and global climate regulation (16 ± 28%). We further found positive pairwise correlations between all ES (Spearman’s ρ from 0.15 to 0.65), with the strongest correlation between habitat maintenance and global climate regulation. Variation in ES delivery across the urban areas was mainly related to differences in the share of green space and the size of the urban areas, whereby ES delivery was positively related to both. Our broad-scale comparative assessment can serve as a starting point for more sophisticated model-based assessments quantifying the full potential of urban nature to meet societal demands across large areas, for example by including a broader set of ES and accounting for city-specific demands.

Advancing urban sustainability transitions: A framework for understanding urban complexity and enhancing integrative transformations

Rapid urbanization and industrialization with their negative repercussions draw attention to the need for urban sustainability. This research built on the urban systems understanding linked with resource utilization, environmental effects, people-environment interactions, and adaptive management by integrating quantitative modelling of urban metabolism with a qualitative investigation into human responses. A hybrid methodology was applied in a typical industrial city of Jinchang, China, which exemplified a model of how complex urban dynamics link to and inform sustainability transitions. The study found that Jinchang City had taken on an unsustainable trajectory underpinned by continuous growth of material consumption, whereas a potential for sustainability transitions was also observed in decoupled negative material outputs, improved material efficiency, and environment regeneration collectively. The challenges in industrial cities have been framed in terms of development model lock-in, conceptual and institutional constraints, innovation and human capital deficiencies, and governance failure. The research proposed a government-led transformation system that integrates multi-level and multi-perspective transformations and management employing discipline insights to facilitate urban sustainability transitions. This involves governance, economic and technological innovations, social transformations, and implementations, in which urban governance and public engagement are essential elements for adapting to undesirable difficulties and exploring locally appropriate strategies. This research provided a theoretical and empirical basis along with scientific and policy implications, which contributed to the developing interdisciplinary knowledge on the understanding of complex urban systems and provided insights into real-world sustainability solutions.

Rethinking Urban Water Management Through Drivers-Pressures-States-Impacts-Responses Framework Application in Chennai, India

Cities suffering water scarcity are projected to increase in the following decades. However, the application of standardized indicator frameworks for assessing urban water resource management problems is on an early stage. India is expected to have the highest urban population facing water scarcity in the world by 2050. In this study, the authors assess how the Drivers-Pressures-States-Impacts-Responses framework, a causal framework adopted by the European Environment Agency, can contribute to evaluate water management challenges in cities and apply it to Chennai, India´s fourth-largest urban agglomeration. The framework proved to be a helpful tool for the evaluation of water management challenges in cities by disentangling relationships between environmental indicators and structuring dispersed data that allows a better understanding for policymakers. The main drivers identified in Chennai were population growth and economic development which generated impacts such as loss of aquatic ecosystems, low water table, low water quality, and reduction of biodiversity and human health. As a response, better urban planning, projects for new water infrastructure, and water bodies restoration have been implemented. Nevertheless, Chennai keeps facing difficulties to achieve proper water management. The severe hit of the COVID-19 pandemic on the Indian economy and its future management will be key for achievements related to water management.

Multi-criteria analysis of low impact development practices: a case study in the Tan Hoa - Lo Gom basin, Ho Chi Minh city, Vietnam

Abstract Urban flooding poses a significant challenge for cities globally. In recent years, Low Impact Development (LID) has been recognized as an effective and sustainable solution for managing urban floods. This study employs the EPA-Storm Water Management Model (EPA-SWMM), social surveys, and multi-criteria analysis (MCA) to assess the effectiveness of LID practices from environmental, social, and economic sustainability perspectives. Results demonstrated that implementing LID techniques such as rain gardens, infiltration trenches, permeable pavements, and their combinations in the Tan Hoa - Lo Gom basin can reduce the average total runoff volume by 8.77% to 30.80% under the current land use-land cover and the design hyetograph with a 3-hour duration and a 5-year return period. Moreover, there is a reduction of approximately 7.42% to 30.59% in the average total runoff volume for the design hyetograph with a 3-hour duration and a 5-year return period, aiming to assess the climate change impact. Additionally, sociological and economic aspects are integrated to comprehensively assess each LID practice through MCA via the Analytical Hierarchy Process (AHP) method. Overall, the analysis results indicated that the scenarios involving the application of rain gardens, infiltration trenches, and their combinations are more effective than other scenarios. These findings will provide valuable insights for decision-making and planning of other LID projects in Ho Chi Minh City (HCMC) to mitigate urban flooding, particularly in light of the escalating challenges posed by urbanization and climate change.

Multi-Year Continuous Observations of Ambient PM2.5 at Six Sites in Akure, Southwestern Nigeria

The spatial–temporal variations of fine particulate matter (PM2.5) in Akure, a city in southwestern Nigeria, are examined based on multi-year continuous observations using low-cost PM2.5 sensors at six different sites. The average annual concentration of PM2.5 across these sites was measured at 41.0 µg/m3, which surpassed both the Nigerian national air quality standard and the World Health Organization air quality guideline level. PM2.5 levels were significantly higher during the dry season (November–March), often exceeding hazardous levels (over 350 µg/m3), than during the wet season. The analyses of trends in air mass trajectories and satellite data on fire occurrences imply that the transport of dust and accumulation of PM2.5 originating from local/regional open burning activities played crucial roles in increased PM2.5 concentrations during the dry season. Further, site-to-site variations in the PM2.5 levels were observed, with relatively high concentrations at less urbanized sites, likely due to high local emissions from solid fuel combustion, waste burning, and unpaved road dust. Diurnal patterns showed morning and evening peaks at less urbanized sites, accounting for an estimated 51–77% of local emissions. These results highlight the importance of local emission sources in driving spatial–temporal PM2.5 variations within the city and the need for targeted mitigation strategies to address the significant air pollution challenges in Akure and similar regional cities in West Africa.

COVID-19 Pandemic and Sustainable Urban Transformation: Perspectives on City-Level Actions and a Framework for the Future

Cities were at the center of the COVID-19 pandemic due to the concentration of affected populations and economic activities that needed to be revived to support global recovery. While cities offer strong economic and social benefits due to density, proximity, and global connectivity, the pandemic had a tremendous impact on their vital functions. It resulted in lost lives and livelihoods and deepened economic and social divides. Furthermore, the pandemic exacerbated many existing environmental challenges in cities. This presented an opportunity to tackle these interlinked challenges in an integrated manner. Evidence suggests that many city leaders integrated environmental sustainability as an important element to complement their emergency responses. Drawing from experiences in cities around the world, particularly those participating in the Sustainable Cities Program supported by the Global Environment Facility (GEF), this paper describes how integrated solutions were applied to tackle the COVID-19 pandemic. Consistent with a Healthy Planet Healthy People concept, a framework is proposed for sustainable urban transformation and to build cities that are resilient to shocks and stresses. With global environmental benefits at the core, the framework highlights the importance of integration, inclusion, and innovation as key approaches in steering the future green growth and prosperity of cities.

Expected Versus Experienced Liveability for Amenity Migrants in Cairns, Australia: The Grass is not Always Greener in the Tropics

ABSTRACT This study explores Australian amenity migrants' experiences in Cairns, comparing expectations of a tropical paradise with lived realities. Using episodic narrative interviews and Importance-Performance Analysis of liveability indicators, it uncovers discrepancies between idealised imaginaries and actual experiences. Key concerns include housing, safety, jobs, living costs, and challenges in building community connections. The findings highlight the gap between the tropical paradise image attracting migrants and liveability challenges of a regional city. This mixed-methods approach offers a transferable tool for examining expectation-experience gaps in amenity destinations, providing insights for policymakers to address liveability issues and build communities that meet diverse residents' aspirations.

Urban security challenges in major cities, with a specific emphasis on privacy management in the metropolises

The rapid growth of urban populations, particularly in the global south, has led to significant challenges in urban security. Insufficient urban security measures can hinder the achievement of future development goals. This study explores the impact of rapid urbanization in capital cities on social, cultural, and environmental issues. The influx of individuals who are not fully integrated into the city can compromise urban security and increase vulnerability in certain groups and areas. The research aims to investigate urban privacy in relation to urban security, with a specific focus on privacy management in the capital city. The study utilizes an applied approach with a descriptive and analytical methodology. The statistical population consists of 856,565 individuals, with a sample of 383 people selected through simple random sampling. The questionnaire was validated by experts, and the reliability of different sections was assessed using Cronbach’s alpha. The findings highlight the influence of factors such as lack of collaboration among security experts, diverse attitudes and political views, and legal and managerial differences on urban privacy vulnerability. Many studies have focused on general urban issues or specific crimes without addressing urban security. Weak regulations, inadequate plans and budgets, and a lack of security equipment are identified as variables affecting the security of the capital city. Managerial, legal, and structural vulnerabilities contribute to insecurity, lawlessness, cultural disparities, and a lack of safety and security in Tehran. The factor with the greatest impact (16.07%) is "coalition between security professionals," while the factor with the smallest impact (6.32%) is "sufficient security for investment and safety in night travel" among the total variables.

Knowledge uptake from lived experience regarding sustainable groundwater management: complementing scientific knowledge in urban policymaking

Urbanization can pose water management challenges in cities while overlooking the possibilities of residents’ lived experience and collaborative action learning. We show how the conceptual model of the Lived Experience of Sustainable Urban Groundwater Level identifies several aspects of local knowledge development through an ex-post case study in Rotterdam’s Flower Neighbourhood (The Netherlands), where too low groundwater levels threaten house foundations. Three types of local knowledge development emerged: (i) performing and monitoring well measurements by residents, (ii) environment-specific insights collected by residents and shared with civil servants, and (iii) collaboration on groundwater management experiments, resulting in empirical groundwater data. Overcoming communication barriers, trust issues, and power dynamics are crucial for effectively retrieving and integrating lived experience into collective learning for urban sustainable development.

Integrated Management of Hazardous Solid Waste in Dental Offices of Talara (Peru) and Machala (Ecuador): A Policy Brief Comparing Two Latin American Countries

Background The improper management of hazardous solid waste in dental care offices poses significant risks to public health and the environment. Dental offices generate hazardous waste, including biological and chemical contaminants, which can lead to infections, pollution, and harm if not managed properly. Effective waste management practices are crucial, yet compliance varies significantly across regions, especially in Latin America, due to limited resources, inadequate training, and insufficient infrastructure. This study compares hazardous waste management practices in dental offices in Talara, Peru, and Machala, Ecuador, to provide actionable recommendations for improvement. Policy and Implications In Peru, hazardous waste management involves critical steps such as conditioning, segregation, transport, storage, treatment, and disposal. Compliance minimizes exposure risks and environmental contamination. Ecuador emphasizes administrative and operational aspects, including policies, records, training, and procedures. Improving practices in both countries can model enhanced waste management across Latin America. Recommendations To address challenges in Talara and similar Latin American cities, it is essential to strengthen administrative systems, increase budget allocations for waste management, and develop comprehensive training programs. Waste management should be prioritized within public policy agendas with clear guidelines and accountability measures. Both cities need improved resource allocation, modern waste treatment facilities, and centralized storage solutions. Continuous education and certification programs are crucial. Implementing integrated policies, regular reviews, and robust compliance mechanisms based on Machala’s practices can benefit other regions. Public awareness campaigns and regional collaboration through workshops and research initiatives are also recommended. Conclusions Significant disparities in hazardous waste management exist between Talara and Machala. Talara requires strengthened systems and improved infrastructure, while Machala’s practices serve as a model. Tailored interventions can enhance public health and environmental outcomes across Latin America. Regular monitoring, evaluation, and collaboration are essential for sustained improvements.

Livelihood Precarity of Migrants: Perspectives of African Refugees in Durban, South Africa

Migrants and refugees face numerous socioeconomic and institutional challenges in the host cities and countries. They are excluded from full participation in the labor market, which makes them vulnerable to poverty. To survive, migrants and refugees join the informal economic sector. Informed by the Sustainable Livelihoods Framework (SLF), the article examines how African refugees in Durban make and maintain their livelihoods, including their encounters with marginalization. Participants were drawn from Congolese, Rwandese, and Burundian community groups living in the inner city of Durban. The snowballing sampling method was key in identifying the participants, while face-to-face interviews were used for data collection. The findings show that African refugees in Durban pursue diverse forms of livelihood in the informal sector. They are faced with numerous challenges, such as a lack of start-up capital, weak social networks to protect themselves and their businesses, bureaucratic challenges, discrimination, and xenophobic attacks. Regardless of these challenges, migrants still forge ahead by starting their businesses and making a living under the circumstances of precarity and marginalization.

Training on Eco-Enzyme Production From Fruit Waste for the Community of Mata Air Village, in Padang Selatan Subdistrict, Padang City

The waste problem is a challenge for cities, especially in developing countries. Waste management is closely related to population, community values and behavior, and existing organizations and systems. Organic waste refers to waste materials that can decompose naturally and be converted into compost. It includes various types of waste, such as food scraps, dry leaves, and vegetables. Based on the literature obtained, it was reported that the City of Padang produces 600 tons of waste daily and ends up in the Final Disposal Site (TPA) without any follow-up or effective management. A very efficient approach to managing organic waste involves transforming the waste into Eco-enzymes, a remarkable discovery made by Dr. Rasukon Poompanvong from Thailand over three decades ago. This eco-enzyme training was conducted on 16 September 2023 at the Cendana residence in Koto Kaciak, Padang City, West Sumatra-Indonesia. The results of the activities presented by the resource person to the community provided knowledge to the community regarding eco-enzymes. Eco-enzyme training for the community has been carried out. It was concluded that eco-enzyme can be used to reduce waste, especially organic waste, which has many benefits.