Metropolitan Scale Research Articles

The Logistics of Waste: Engineering, Capital Accumulation, and the Growth of Mexico City

AbstractHow is capital accumulation sustained in the Anthropocene, even as it threatens to overwhelm everyone—capitalists included—in ever‐growing quantities of waste? This paper examines this question at the metropolitan scale, focusing on the growth of Greater Mexico City. In a bid to spur capital accumulation, governments across the megacity increasingly push for new urban developments that encroach on the already‐strained drainage system, limiting its capacity to prevent floods. To protect these developments, state engineers now regularly divert wastewater through the homes and streets of marginalised areas of the metropolis. Even as these diversions turn marginal neighbourhoods into ephemeral waste conduits, the transience of wastewaters and the complexity of engineers’ operations limit the possibilities for collective resistance. This calculative management of the flows of waste—here termed the logistics of waste—is a critical yet understudied way engineering sustains the accumulation of capital and limits popular resistance to elite‐led projects of endless growth.

An assessment of key factors to a metropolitan governance for the construction of sustainable urban public policies for the integral management of solid waste in the metropolitan area of Guadalajara

Territory and population of Guadalajara metropolitan area has grown in recent decades, to address the challenges that come along with planning, management, and urban development. Public policies are building by the local government, however, the loss of geographical and social limits, the actions generated by local government have a direct impact on other districts. To achieve tan equitable and sustainable metropolis, its necessary the metropolitan governance, to make a collaborative work and clearly guidelines to action. Faced with a clear problem at the metropolitan scale with solutions at the local level and uncoordinated forces to build and implement public policies; this paper analyzes the exercise of governance on the integral management of urban waste to the construction of sustainable and equitable public policies in the Metropolitan Area of Guadalajara. The research is based on a Delphi method, interviews with representative actors of different involucrate sectors and a documentary review for a comprehensive analysis. Finally, the knowledge of the research presented here; has increased in importance given the recent approval of the Metropolitan Climate Action Plan. The municipalities that make up the metropolis must align themselves and unite their efforts for a sustainable development.

Spatial Configuration of Logistics Firms Relative to Cape Town International Airport, South Africa

Background: A multi-faceted analysis of the positioning of logistics facilities relative to airports is a topical aspect of the interconnections between transport infrastructure and the spatial configuration of economic activities. Regardless of the wide range of studies that exist on the topic, little is known about the logistics catchment of airports. Towards extending the literature, the objective of the paper is to analyse the spatial configuration of logistics firms relative to Cape Town International Airport (CTIA) in South Africa. Methods: The inclination of logistics facilities to locate in industrial areas is widely acknowledged in the literature. As such, the data on the main industrial and economic nodes in the City of Cape Town metropolitan area were obtained from the City of Cape Town municipality and used to ascertain the extent of the industrial areas across the metropolitan area. The resultant geographic information system (GIS) shapefile of the industrial and economic nodes was used to obtain the logistics firms’ data from AfriGIS. Following the cleaning of the data from AfriGIS, ArcGIS 10.8 and QGIS 3.16 were used for spatial analysis (buffer, kernel density and network analysis) to establish the spatial configuration of the logistics firms relative to CTIA. Results: The results showed that of the 985 logistics firms in the metropolitan area, 937 were located within 20 km of CTIA. Furthermore, the kernel density results showed that high density values were found in the environs of the Cape Town central business district (CBD), Port of Cape Town and Milnerton. The results of the network analysis indicated that the furthest firm was 50 km and 64 min away on the shortest route to CTIA, while it was 55 km and 49 min away on the fastest route. Conclusions: Relative to the literature, the results show that CTIA has the potential to facilitate the emergence of a logistics hub at the city or metropolitan scale.

Using crowdsourced imagery to assess cultural ecosystem services in data-scarce urban contexts: The case of the metropolitan area of Cali, Colombia

Sustainable urban and metropolitan planning is increasingly benefiting from differentiated assessments of ecosystem services. Cultural ecosystem services (CES) are particularly relevant for urban residents’ mental and physical health, yet, quantification and mapping of CES are often challenging, especially so in the Global South. The use of social media data (SMD), which has recently gained importance for assessing CES at larger spatial and temporal scales, provides a promising entry point for mitigating this informational gap in land-use planning. However, its application is mainly limited to European and North American cases and rarely applied to data-scarce urban regions in the Global South, with South America as no exception. Addressing this geographical gap, this study assesses CES of urban green spaces in the city of Cali, Colombia, based on 1,686 crowdsourced and geolocated photographs, and compares those results with a metropolitan scale CES potential assessment based on expert opinions performed in a previous study. Despite some important limitations primarily related to Flickr as a data source, we demonstrate the utility of this approach, especially for understanding the fine-scale generation of CES by small green spaces located within the urban fabric that are overlooked in the metropolitan scale expert-based assessment. These green spaces are highly relevant as inner-city pockets for CES production, especially in the form of “existence value” and “aesthetic experiences”, in contrast to green areas highlighted by experts at the metropolitan scale that serve primarily recreational purposes. Our results indicate the large potential of SMD-based CES assessment approaches for informing urban planning processes in the Global South.

Telecom-Band Quantum Interference of Frequency-Converted Photons from Remote Detuned NV Centers

Entanglement distribution over quantum networks has the promise of realizing fundamentally new technologies. Entanglement between separated quantum processing nodes has been achieved on several experimental platforms in the past decade. To move towards metropolitan-scale quantum network test beds, the creation and transmission of indistinguishable single photons over existing telecom infrastructure is key. Here we report the interference of photons emitted by remote, spectrally detuned NV center-based network nodes, using quantum frequency conversion to the telecom L-band. We find a visibility of 0.79$\pm$0.03 and an indistinguishability between converted NV photons around 0.9 over the full range of the emission duration, confirming the removal of the spectral information present. Our approach implements fully separated and independent control over the nodes, time-multiplexing of control and quantum signals, and active feedback to stabilize the output frequency. Our results demonstrate a working principle that can be readily employed on other platforms and shows a clear path towards generating metropolitan scale, solid-state entanglement over deployed telecom fibers.

Spatio-Temporal Evolution and Quality Analysis of Construction Land in Urban Agglomerations in Central China

Understanding the pattern and quality of construction land expansion in urban agglomerations is important for new urbanization and high-quality development of land spaces. Taking urban agglomeration in the middle reaches of the Yangtze River as the research object, this study analyzes the spatio-temporal pattern and quality level of construction land expansion at various scales using remote sensing images, the expansion intensity index, the coordination degree model, and the Tapio elastic decoupling model. The results show that from 2000 to 2020, (1) the construction land scale of urban agglomeration in the study area had expanded, with significant stage characteristics and spatial differentiation patterns. (2) The overall relationship between the construction land and the population in urban agglomerations was found to be uncoordinated, but the coordination degree had been improved. The optimization of human–land coordination was faster at the metropolitan scale than at the overall level and the sub-urban agglomerations. (3) The decoupling relationship between the overall construction land and the economy in urban agglomerations was weak and had improved. The coupling/decoupling relationship was found to be better at the metropolitan scale than at the overall level and sub-urban agglomerations.

The strategic-relational formation of regional and metropolitan scales: studying two Polish regions undergoing transformation

ABSTRACT This paper aims to capture a given spatio-temporal fix in the regional and metropolitan formation processes within two Polish regions: Lubelskie and Silesia. The strategic–relational approach (SRA) to the state analysis was adopted to discern the key elements of regional and metropolitan discourses. The wide SRA framework allows us to situate these discourses within formal and substantive dimensions of both scales, and then – using the territory–place–scale–networks (TPSN) framework – to connect them to the other aspects of socio-spatial relations. The selected regions occupy a special place within regional policy in Poland and discourse at a national level due to structural problems within their territories. Therefore, different actors have identified the need for thorough regional transformations. In turn, they should be analysed in the context of the state transformation, which began in Poland in 1989, with its currently unknown direction when it comes to the modes of regional and metropolitan policies. The results of the research prove that specific actors adopt regionally different strategies, aiming at pursuing their own goals as well as supporting regional raison d’états. At the same time, however, it is difficult to indicate evidence of political rescaling concerning the transfer of tasks and resources to the regional scale, except for its strengthening resulting from the implementation of European Union funds, which can be considered in terms of governance or meta-governance failure. The ‘stewards of hope’ image has been assigned in this context to new metropolitan-scale institutions.

Governing the Metropolis: An International Review of Metropolitanisation, Metropolitan Governance and the Relationship with Sustainable Land Management

Recent research has identified the potential of the metropolitan scale, and indeed metropolitan bodies, in achieving greater coordination and more effective land-use management. In this paper, we have undertaken a systematic scoping review of the English-language literature (2014–2019) on metropolitanisation and metropolitan governance, with a view to understanding the potential relationship with more sustainable land management. Our scoping review identified several dominant trends within current research on metropolitanisation and metropolitan governance illustrating the complexity between sustainable land management and issues of territorial politics, resourcing, and power relations. The centrality of collaborative working relationships in supporting sustainable land management is identified, yet collaboration and effective metropolitan scale governance is not always an easy task or readily implemented. The paper identifies a series of challenges and concludes that while there is general consensus that the metropolitan arena may be an appropriate scale through which to support more sustainable land management, there is no agreement on the mechanisms to enable this. Steering and more strongly directing metropolitanisation processes through either formal metropolitan governance structures or other tools could provide a potential approach but will require significant adaptation in power and funding structures.

Reported Occurrence of Multiscale Flooding in an Alpine Conurbation over the Long Run (1850–2019)

This paper deals with the identification of extreme multiscale flooding events in the Alpine conurbation of Grenoble, France. During such events, typically over one to several days, the organization in space and time of the generating hydrometeorological situation triggers the concurrent reaction of varied sets of torrents and main rivers and creates diverse socioeconomic damages and disruptions. Given the limits of instrumental data over the long run, in particular at the torrent scale, we explore the potential of a database of reported extreme flood events to study multiscale flooding over a Metropolitan domain. The definition of Metropolitan events is mainly based on the database built by the RTM (Restauration des Terrains de Montagne, a technical service of the French Forest Administration). Relying on expert reports, the RTM database covers the long lifetime of this French national service for the management of mountainous areas (1850–2019). It provides quantitative information about the time and place of inundation events as well as qualitative information about the generating phenomena and the consequent damages. The selection process to define Metropolitan events simply chronologically explores the RTM database and complements it with historical research data. It looks for concurrence between site events at the same date under a chosen set of criteria. All scales together, we selected 104 Metropolitan events between 1850 and 2019. Exploring the list of dates, we examine the homogeneity of the Metropolitan events over 1850–2019 and their space–time characteristics. We evidence the existence of multiscale flooding at the Metropolitan scale, and we discuss some implications for flood risk management.

Planning for low-carbon energy-transportation system at metropolitan scale: A case study of Beijing, China

The urbanization and expansion of megalopolises have led to concerns on traffic, energy crisis and deteriorated green-house gas emissions, and thus the electric vehicles (EVs) are expected to be an essential role in alleviating these problems. In this study, a flexible-possibilist chanced constraints programming (FCCP) model is developed to plan low-carbon energy-transportation systems at the metropolitan scale (METS), which can incorporate multiple uncertainties in both the soft constraints and objective function. By integrating the possibilist programming with fuzzy sets and chanced constraint, the FCCP could tackle multiple complexities such as the combination of vague possibilities, flexibilities and probabilities, hence is superior to conventional approaches. The FCCP model is then applied for the planning METS in Beijing, and solutions are obtained under different satisfactory degrees and confidence levels. The results reveal that: 1) the power demand will be increasingly dependent on the imported power and renewable energy in Beijing; 2) the mass roll-out of EVs will reduce 6.7 million tonnes of CH, 44.7 million tonnes of CO and 1.08 × 105 million tonnes of CO2 respectively, while the need of battery supply facilities will cost approximately 4 × 109 dollars; 3) the carbon emissions will decrease with the growing number of EVs, the upgraded power supply pattern and the stringent policies. These findings could support decision-makers to plan the METS system when faced with multiple uncertainties.

How Many Private Cars Can Be Reduced by the On-Demand Car-Sharing Services at a Metropolitan Scale?

How Many Private Cars Can Be Reduced by the On-Demand Car-Sharing Services at a Metropolitan Scale?

Exploring the impacts of online food delivery service on facility distribution: A case of Jakarta, Indonesia

Multi-service transport platforms (MSTPs) such as GOJEK and GRAB, providing access to many services without traveling, may lead to changes in activity and travel decisions, in turn leading to changes in the distribution of facilities, evidenced by a different distribution pattern and spatial concentration of online food merchants that only provide online food delivery services. This study empirically explores the impacts of MSTPs on food merchant distribution in Jakarta by identifying differences in distributions of dine-in and online food merchants. Our empirical results focusing on the agglomeration of facilities with different spatial scales showed that, while dine-in food merchants are more agglomerated at the metropolitan scale, online food merchants are more agglomerated at the neighborhood scale, presumably due to the necessity to attract MSTP drivers to keep the delivery service level. We also found that online food merchants tend to be agglomerated in the center and fringe area of the city.

Design and Implementation of the Illinois Express Quantum Metropolitan Area Network

The Illinois Express Quantum Network (IEQNET) is a program to realize metropolitan scale quantum networking over deployed optical fiber using currently available technology. IEQNET consists of multiple sites that are geographically dispersed in the Chicago metropolitan area. Each site has one or more quantum nodes (Q-nodes) representing the communication parties in a quantum network. Q-nodes generate or measure quantum signals such as entangled photons and communicate the measurement results via standard, classical signals and conventional networking processes. The entangled photons in IEQNET nodes are generated at multiple wavelengths, and are selectively distributed to the desired users via transparent optical switches. Here we describe the network architecture of IEQNET, including the Internet-inspired layered hierarchy that leverages software-defined networking (SDN) technology to perform traditional wavelength routing and assignment between the Q-nodes. Specifically, SDN decouples the control and data planes, with the control plane being entirely implemented in the classical domain. We also discuss the IEQNET processes that address issues associated with synchronization, calibration, network monitoring, and scheduling. An important goal of IEQNET is to demonstrate the extent to which the control plane classical signals can co-propagate with the data plane quantum signals in the same fiber lines (quantum-classical signal "coexistence"). This goal is furthered by the use of tunable narrow-band optical filtering at the receivers and, at least in some cases, a wide wavelength separation between the quantum and classical channels. We envision IEQNET to aid in developing robust and practical quantum networks by demonstrating metro-scale quantum communication tasks such as entanglement distribution and quantum-state teleportation.

Heat vulnerability and extreme heat risk at the metropolitan scale: A case study of Taipei metropolitan area, Taiwan

Global climate change has intensified extreme climate events, such as torrential rain, heavy snow, heatwaves, and droughts. Among all extreme disaster events, extreme heat might lead to long and intensified heatwaves and seriously impact human living environments and ecological habitats. This study applies remote sensing to identify the spatial variation in extreme heat and principal component analysis (PCA) to explore the spatial distribution of the heat vulnerability index in the Taipei metropolitan area. Finally, a bivariate local indicator of spatial association (bivariate LISA) is used to explore the relationship between extreme heat and the heat vulnerability index. The results show that most vulnerable villages are clustered in downtown Taipei. In addition, the bivariate LISA results show an aggregation of 346 high-high clusters, indicating extreme heat and relatively high vulnerability clustered in particular areas. The findings of this study could provide the basis for proposing adequate resilience strategies for areas suffering from extreme heat based on the heat vulnerability composition.

Green infrastructure connectivity analysis across spatiotemporal scales: A transferable approach in the Ruhr Metropolitan Area, Germany

Developing green infrastructure (GI) has drawn increasing attention as a strategic planning approach for advancing urban sustainability. The connectivity of green spaces, a central principle of GI, has been considered in planning studies regarding its structure and functions for biodiversity conservation and ecosystem services delivery; however, aspects of GI connectivity across temporal and spatial scales are rarely addressed. This paper aims to develop and apply a method for the GI connectivity analysis at multiple spatiotemporal scales. A transferable and multi-scale workable approach is presented to reveal the changes of structural and spatial heterogeneity of urban GI. Our method includes i) morphological spatial patterns analysis for central and green corridors recognition, ii) a graph-based quantification of GI connectivity based on the Conefor model, and iii) least-cost path analysis for identifying potential green corridors. We apply the GI connectivity analysis method in the Ruhr Metropolitan Area (RMA), one of Europe's largest agglomerations. We use spatial Urban Atlas data from 2006 to 2018. At the metropolitan scale, we find that GI connectivity in the RMA decreases 3.9% from 2006 to 2018, even though the general distributions of GI changes only slightly. With reference to the municipal scale from 2006 to 2018, four major types of GI connectivity changes were discovered in RMA's 15 cities, namely consistent decreasing, consistent increasing, increase followed by decrease, and vice-versa. Our findings provide new evidence on GI connectivity changes across a twelve-year difference and at metropolitan and municipal scales, as well as the identification of priority areas for increasing GI connectivity. It provides insights on the evolving and heterogenous nature of GI connectivity in support of decision-making for more sustainable metropolitan development for people and nature.

Air Quality and Active Transportation Modes: A Spatiotemporal Concurrence Analysis in Guadalajara, Mexico

The protection of pedestrians, cyclists, and public transportation passengers from environmental pollution is a global concern. This study fills the gap in the existing knowledge of temporal exposure to air pollution in Latin American metropolises. The paper proposes a methodology addressing the relationship between two objects of study, i.e., the users of active modes of transport and air quality. This new methodology assesses the spatiotemporal concurrence of both objects with statistical analysis of large open-access databases, to promote healthy and sustainable urban mobility. The application of the empirical methodology estimated the number of users of active transportation modes exposed to poor air quality episodes in the Guadalajara metropolitan area (Mexico) in 2019. The study considered two pollutants, ozone (O3) and particulate matter (PM10), and two active modes, cycling and bus rapid transit (BRT). Spatiotemporal analyses were carried out with geographic information systems, as well as with numeric computing platforms. First, big data were used to count the number of users for each mode within the area of influence of the air quality monitoring stations. Second, the number of air pollution episodes was obtained using the air quality index proposed by the Environmental Protection Agency (USA) on an hourly basis. Third, the spatiotemporal concurrence between air quality episodes and active mode users was calculated. In particular, the air quality monitoring data from the Jalisco Atmospheric Monitoring System were compared to users of the public bicycle share system, known as MiBici, and of a bus rapid transit line, known as Mi Macro Calzada. The results showed that the number of cyclists and BRT passengers exposed to poor air quality episodes was considerable in absolute terms, that is, 208,660 users, while it was marginal when compared to the total number of users exposed to better air quality categories in the study area, who represented only 10%. To apply the results at the metropolitan scale, the spatial distribution of the air quality monitoring system should be improved, as well as the availability of data on pedestrians and conventional bus passengers.

Field study of the indoor environments for preventing the spread of the SARS-CoV-2 in Seoul.

Despite the prolonged global spread of COVID‐19, few studies have investigated the environmental influence on the spread of SARS‐CoV‐2 RNA with a metropolitan scale, particularly the detection of SARS‐CoV‐2 after disinfection at multi‐use facilities. Between February 2020 and January 2021, 1,769 indoor air samples and object surfaces were tested at 231 multi‐use facilities where confirmed cases were known to have occurred in Seoul, to determine whether SARS‐CoV‐2 RNA could be detected even after disinfection. Samples were collected by air scanner and swab pipette and detected by real‐time RT‐PCR. As a result, 10 (0.56%) positive samples were detected despite disinfection. The common environmental features of all 10 were surfaces that contained moisture and windowless buildings. With the aim of preventing the spread of COVID‐19, from January to February 2021, we next conducted 643 preemptive tests before the outbreak of infections at 22 multi‐use facilities where cluster infections were frequent. From these preemptive inspections, we obtained five (0.78%) positive results from two facilities, which enabled us to disinfect the buildings and give all the users a COVID‐19 test. Based on the study purpose of finding and investigating cases of positive detection even after disinfection in the field through long‐term environmental detection in a large city, our preemptive investigation results helped to prevent the spread of infectious diseases by confirming the potential existence of an asymptomatic patient.

A seat at the table? Transit representation in U.S. metropolitan planning

Since the early 1990s, U.S. metropolitan planning organizations (MPOs) have had increasing room to shape the extent to which public transit benefits from regional transportation spending. Federal law has given MPOs widening latitude over this period to use highway-oriented funding for transit investment. Yet, concerns that public transit operators—and, by extension, transit needs—have been underrepresented in MPO decision-making are longstanding. This paper reports on the first comprehensive inventory of transit representation on MPO decision-making boards. MPOs and the planning process they oversee allow metro regions to tap federal funds, and together MPOs approve billions in metropolitan transportation investment across the U.S. We study these important institutions in the transportation landscape and how they provide for transit participation. We find that transit's actual voting representation on MPOs is somewhat higher than previously estimated, suggesting that recent federal policies have modestly increased formal transit involvement in investment decisions. We also find that different forms of board representation for transit—direct and indirect—can produce disparities in transit's influence from one region to the next. These findings reveal the impact of federal transportation laws on metropolitan scale decision-making and highlight some of the enduring institutional challenges to broadening participation in regional transportation governance. They also pave the way for further studies of the impact of MPO representation on transit expenditures by MPOs.

Magnitude and distribution of the untapped solar space-heating resource in U.S. climates

Space heating is the single greatest source of building-related greenhouse gas emissions in the industrialized world, giving urgency to the development of strategies for carbon-free heating. Recent advances have shown that the direct capture, storage, and deployment of solar energy, without conversion to electricity, has considerable potential to address space-heating needs even in cold and cloudy climates. However, the solar energy available for direct heating at climatic and metropolitan scales is both unquantified and widely assumed to be negligible, impeding further investigation, development, and policy responses. To estimate the magnitude and distribution of solar resources concurrent with space-heating needs, we spatially integrate datasets characterizing solar radiation, outdoor temperature, and heating energy use across U.S. climates. Results show that the median resource incident upon collectors of residential scale (10m2) and distribution is much greater than previously realized, equaling 7MWh per household annually; by comparison, the median household heating need is currently 10.3MWh. Unexpectedly, cloud-diffused solar radiation accounts for over one-quarter of this resource in all but semi-arid climates. Metropolitan residential resources exceed 5TWh in areas including Detroit and Boston (cold continental), WashingtonD.C. (humid subtropical), Seattle and San Francisco (Mediterranean), and Denver (semi-arid), and national resources exceed 750TWh annually, compared to approximately 1200TWh of annual heating need. Current technology is able to capture and retain over half of a direct solar heating resource, revealing that the untapped U.S. solar heating potential is comparable to one-third of the national residential space-heating need and implying that analogous resources exist in analogous climates worldwide.

GIS-based compactness measurement of urban form at neighborhood scale: The case of Dhaka, Bangladesh

Compact development is broadly professed for making significant contributions to achieve sustainable growth of cities. Therefore, evaluation of the existing compactness of urban areas is crucial for guiding future urban development. Previous studies measured urban areas' compactness at a city or metropolitan scale in a developed country context. Hence, a considerable research gap exists in studying compactness at the neighborhood scale, especially in urban areas from a developing country. This paper aims to evaluate and compare compactness level of neighborhoods in the GIS environment through broadly six indicators-population density, evenness of development, clustering nature of development, land-use diversity, floor use mix, and road network connectivity in eight neighborhoods of Dhaka city, Bangladesh. For this, the study developed a Composite Compactness Index (CCI) based on a multi-criteria decision-making (MCDM) approach. Study results classified four neighborhood as low compact, three as moderately compact, and one as high compact neighborhood. Travel behavior analysis through modal share, travel time, and travel distance validated compact neighborhoods' tenability. Here, identified low and moderate compact neighborhoods require immediate planning interventions for improving their compactness level. Results from this study can work as a preliminary guideline for planners, policymakers, and development agencies for designing a more sustainable and efficient urban form through compact urban development on neighborhood scale. The developed methodology presented here can be applied to other areas with refinements necessary for corresponding geographic location.