Dense Urban Settings Research Articles

Comparison of Urban Environment Factors for Solar-Powered Vehicles

Abstract. Urban areas face significant environmental challenges, including high CO2 emissions largely attributed to the transportation sector. Introducing solar-powered vehicles (SPVs) presents a promising solution to reduce urban carbon footprints. However, in dense urban settings, the effectiveness of SPVs is often compromised by shading from buildings, which significantly diminishes solar power generation. This study explores the impact of shading on urban roads, aiming to identify roads with substantial shadow variations that affect solar energy harvesting. Using Geographic Information Systems (GIS) and hillshade analysis, the study examines how nearby buildings and road orientation influence shadow variability. The findings reveal considerable variability in shadow throughout the year, with significant fluctuations during transitional months like February, August, October, and November. These results highlight the importance of considering shadow patterns in urban planning and vehicle routing to optimise the use of solar energy in urban settings.

Planning for Risky Play: From Child-Safe Playgrounds Towards Adventurous Urban Areas

A reduction of urban space dedicated to outdoor play has occurred in recent decades, accompanied by a focus on risk reduction when planning for play. Experts increasingly argue in favor of risky play and enabling settings in the urban outdoors. In this paper we examine how risky play is enabled and constrained in two Dutch cities – frontrunners in this debate. Through analyzing path dependencies and institutional change, our qualitative case study (document analysis, expert interviews and focus group) demonstrates some early indicators of a paradigm shift, but also shows the complexity of planning for risky play in dense urban settings.

Developing a strategy of data collection and pre-processing to assess bike-sharing system station placements with the help of GIS

Our research presents a methodological framework for analyzing bicycle-sharing systems, using the self-service bike operations of JCDecaux in Toulouse as a case study. The objective was to identify a method for obtaining a cleansed and structured attribute list that could be useful in evaluating and optimizing the placement of bicycle rental docks. Utilizing open data, our approach involves developing a Python script within QGIS to create new layers around each of the 288 studied bicycle rental stations, based on a selected 100-meter buffer. This buffer size is chosen to reduce data overlap in dense urban settings. The script is designed to collect urban features within these buffers that register as multipolygons (mainly buildings) or points (amenities, transportation features), moreover it applies categorization of data, such as identifying and marking the different building types. The method includes a basic visualization of potential data in QGIS using OpenStreetMap.

SANITATION-SAFETY- PLANNING (SSP), THE NEXUS FOR CLIMATE RESILENCE, SANITION AND HEALTH IN BAYELSA STATE

In recorded human history, climate-related hazardous events have always existed; however, climate change has proved to have the potential to increase their severity and the likelihood of creating public health risks. In Bayelsa State, a sizable portion of the population has been reported to be suffering from gastrointestinal disorders particularly diarrhea and a number of children have been diagnosed of gastroenteritis and helminthes infections in the year 2021. Again, preventing exposure and contact to human waste, especially in dense urban settings requires the safe management of the entire sanitation service chain involving multiple actors and exposed groups in the collection, transport, treatment, disposal and end use of sanitation waste. To that end, a review of scientific literature, particularly the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (IPCC, 2014), the WHO discussion Paper on Climate, Sanitation and Health (WHO, 2019) and the Bayelsa State SSP zero draft of 2021, is undertaken to ensure that climate change outcomes are considered within the Sanitation Safety Planning (SSP) risk assessment, planning and management processes. The SSP is a WHO risk based management tool for the safe use and disposal of grey water, wastewater and excreta developed in 2006 because in 2018 the WHO concluded that sanitation interventions have shown lower than expected health outcomes. Evidently therefore, the Bayelsa State SSP zero draft of 2021 reports that between March and April 2021, over 200 cases were reported from over 30 communities arising from the outbreak of acute-gastroenteritis suspected to be of cholera, and casualty figures were over 26. Hopefully, the first comprehensive Guidelines on Sanitation and Health which aim to provide evidence-based recommendations and offer guidance to ensure international, national and local sanitation policies and programmes that effectively protect public health, was launched by the WHO in 2018. It is a step-by-step risk based approach to implementing local level risks assessment and a management tool for the entire sanitation service chain covering containment, conveyance, treatment and end use of disposal. Consequently, the SSP is hereby recommended for adoption in Bayelsa State and Niger Delta Region.

Micro and macro urban heat islands in an industrial city: Bradford, UK

The urban heat island (UHI) phenomenon refers to the temperature difference(s) between urban/built environments and suburban/natural areas. It affects energy use, health, water quality, and in brief, the quality of life in cities. Understanding the magnitude of this issue could help urban planners and decision makers to better implement green interventions into their cities. This paper shows the results of field measurements carried out to study the UHIs in Bradford, as one of the most deprived cities in the UK with minimum green infrastructure. In the first phase of the study, air temperatures were measured in twenty locations (four areas) with different land covers in Bradford. These measurements were called micro UHI study, as the air temperatures were measured in areas within the boundaries of the city. Data were collected in late summer and early winter. The results showed that the UHI is more sensible in the colder day (with average 0.6 °C cooler air temperature in a green area compared to the city centre). Greener areas experienced higher wind and lower air temperatures compared to dense urban settings in December. In the second phase of the study (macro scale), diurnal air temperatures from a residential (urban) versus a rural site were compared during a heat wave episode (seven days). It was observed that the rural site was 0.8 °C cooler than the residential/urban site. The maximum temperature differences occurred during the nights/early mornings between the two sites (3.2 °C at 5:00am).

A Hopular based weighting scheme for improving kinematic GNSS positioning in deep urban canyon

Global navigation satellite system (GNSS) positioning performance in the urban dense environment experiences significant deterioration due to frequent non-line-of-sight (NLOS) and multipath errors. An accurate weighting scheme is critical for positioning, especially in urban environment. Traditional methods for determining the weights of observations typically rely on the carrier-to-noise density ratio (C/N0) and the elevations from satellites to receivers. Nevertheless, the performance of these methods is degraded in the dense urban settings, as C/N0 and elevation measurements fail to fully capture the intricacies of NLOS and multipath errors. In this paper, a novel GNSS observations weighting scheme based on Hopular GNSS signal classifier, which can accurately identify the LOS/NLOS signals using medium-sized training dataset, is proposed to improve the urban kinematic navigation solution in real-time kinematic positioning mode. Four GNSS features: C/N0, time-differenced code-minus-carrier, loss of lock indicator and satellite’s elevation, are employed in the training of the Hopular based signal classifier. The performance of the new method is validated using two urban kinematic datasets collected by a U-blox F9P receiver with a low-cost antenna, in downtown Calgary. For the first testing dataset, the results show that the Hopular based weighting scheme outperforms the three most commonly used GNSS observations weighting schemes: C/N0, elevation, and a combined C/N0-elevation approach. Approximately 10.089 m of horizontal root-mean-squared (RMS) positioning error and 12.592 m of vertical RMS error are achieved using the proposed method; with improvements of 78.83%, 46.82% and 43.27% on horizontal positioning accuracy and 54.00%, 47.51% and 49.69% on vertical positioning accuracy, compared to using C/N0, elevation and C/N0-elevation combined weighting schemes, respectively. For the second testing dataset, a similar performance is achieved with nearly 11.631 m of horizontal RMS error and 10.158 m of vertical RMS error; improvements of 64.58%, 32.90% and 22.40% on horizontal positioning accuracy and 71.99%, 65.24% and 55.88% on vertical positioning accuracy are achieved, compared to using C/N0, elevation and C/N0-elevation combined weighting schemes, respectively.

Unveiling the magic of mega-city block environments: investigating the intriguing mechanisms shaping children's spontaneous play preferences.

This study delves into the spatial preferences of children for play spaces within high-density urban block environments, specifically targeting the area of Baihua Second Road in Shenzhen, China. Recognizing the critical role of play in children's development, and the unique challenges posed by dense urban settings, this research employs multiclass logistic regression models and negative binomial regression models to construct a detailed mathematical analysis of neighborhood spatial elements and children's play space preferences. Data was meticulously gathered through both objective observations of 14 different types of spaces within the block, and subjective assessments via children's responses to a series of environment photos, capturing the essence of over 3,000 child participants' interactions and choices. Key findings reveal a pronounced preference among children for soft facility features and visually appealing spatial experiences, suggesting a nuanced understanding of play space needs beyond traditional playground designs. Notably, the study identifies that while cartoon-style designs in play facilities might increase moderate attractiveness, ordinary designs hold broader appeal, indicating a preference for diversity in play space aesthetics. These insights offer profound implications for urban planners and designers, advocating for a child-centered approach in the creation of urban play environments that prioritize aesthetic diversity, and the integration of natural elements. Moreover, the study situates Baihua Second Road as a paradigmatic case, illustrating the methodology and analytical framework applied in addressing the complex interplay between children's play preferences and urban spatial configurations. By incorporating a comprehensive data-driven analysis, this research contributes significantly to the discourse on child-friendly urban design, offering valuable strategies for cultivating inclusive and engaging urban play spaces for children amidst the constraints of high-density city living.

Too close for comfort? Impact of pandemic residential environment on women’s life satisfaction and spousal relationships

Few studies have examined the role of residential conditions during different phases of the pandemic on life satisfaction and spousal relationships. Using survey data on 440 married women collected before, during and after the COVID-19 lockdown in Singapore, this article tests the hypothesis that residential crowding, co-residence with children or parents/in-laws and lack of access to private open, green spaces during the lockdown are associated with worsened life satisfaction and spousal relationships. Multinomial logistic regression results suggest that married women in more spacious homes were significantly less likely to experience worsened life satisfaction at the peak of movement restrictions (RRR = 0.967, p = .037), and that having access to open spaces was associated with improved life satisfaction (RRR = 3.536, p = .018) and spousal relationships (RRR = 2.267, p = .032). Housing policy in dense urban settings can increase population well-being and resilience by increasing access to co-working spaces and open green spaces.

Quantifying the Variability of Ground Light Sources and Their Relationships with Spaceborne Observations of Night Lights Using Multidirectional and Multispectral Measurements.

With the transition to LED lighting technology, multispectral night-time sensors are needed to quantify the changing nightscapes, given the limitations of the panchromatic sensors. Our objective was to quantify the contribution of lighting sources as measured on the ground and examine their correspondence with night-time brightness and color as measured from space. We conducted ground-based measurements of night-time brightness using the multidirectional (top, rear, right, front, left) and multispectral LANcube v2, which was mounted on the roof of a car, over 458 km of roads in central Israel and in Brisbane, Australia. For spaceborne measurements, we used the SDGSAT-1 multispectral Glimmer sensor. We found that spaceborne measurements of apparent radiance were best explained when including all ground-based directional measurements, with greater explanatory power for highways (R2 = 0.725) than for urban roads (R2 = 0.556). Incoming light in the five directions varied between road classes and land use. In most cases, the variability in night-time brightness and color was greater for urban road sections than for highways. We conclude that due to the spectral mixture of lighting sources, at a medium spatial resolution, the impact of the transition to LED lighting may be more easily recognized from space over highways than in dense urban settings.

Locally contextualized psycho-physiological wellbeing effects of environmental exposures: An experimental-based evidence

Geographically-distributed urban environment contexts affect human psychological wellbeing through the real-time interactions between individuals and their surroundings. Recent field experiments have become particularly interesting in using wearable devices for tracking episodic changes in wellbeing outcomes. However, most research primarily contribute to correlate unconscious physiological arousal with single environmental feature, ignoring the contextualized environment neural psychological effects at the brain level. This paper studies the effects of walking exposures to various urban environment contexts on neural physiological and psychological parameters relevant to mental health in women cohorts. We measure neural physiological parameters using a functional near-infrared spectroscopy (fNIRS) monitoring approach to detect brain activity variability during a journey-based field experiment, and perceived psychological wellbeing outcomes are measured through emotional questionnaires. A group of 10 healthy women walked across dense and diverse urban settings in Guangzhou, China. We have identified the beneficial effects of blue-green spaces and open spaces on psychological wellbeing, as well as their underlying neurophysiological mechanisms that exhibit localized context differentiation. Additional results quantify evidence in support of spatial typology and travel sequence-based uncertainties as underlying channels at work. Our study provide a walking-oriented investigation model of locally contextualized mental health effects, and expand explanatory method for walking mental health. It also suggests the importance of conceptualizing landscape complementarities in planning policies that help to improve the interaction between wellbeing and localized environmental exposures.

Wellbeing fostered by design: a framework for evaluating indoor environment performance

High-rise urban development has been controversial for its inability to foster cohesive and flourishing neighbourhoods. A social value perspective can help to better understand and evaluate how new developments in dense urban settings affect places and communities. While the link between wellbeing and social value is well-established in the literature, the question of how design can affect wellbeing and thus contribute to the social value of a development still requires further research and clarification. A better understanding of this relationship can assist architects, developers or consultants during the design process. A review is presented of relevant quantifiable aspects of building design that affect wellbeing in relation to the indoor environment and to social value specifically. A framework for fostering wellbeing is developed to test these aspects and evaluate the indoor environment performance. A case study building is used to analyse the relationship between building design and wellbeing. These lessons can be used to inform and evaluate building design during the design phases to complement the assessment of qualitative factors within a social value framework. Practice relevance This study identifies quantifiable aspects of the indoor environment affecting wellbeing in a high-rise development that can form part of a social value framework. This list of identified aspects provides a useful starting point for architects or consultants to assess designs. The indicators relate to quantifiable indoor environment aspects that can be directly controlled by building design and complement the broader concepts of wellbeing within a social value framework. The paper demonstrates how these aspects can be quantified in a case study mixed-use urban development as part of a post-occupancy evaluation. These quantifiable aspects could be integrated within digital tools to evaluate the building at the design stage to ensure that wellbeing is at the forefront of the project considerations.

Urban microclimate and climate change impact on the thermal performance and ventilation of multi-family residential buildings

Urban settings and climate change both impact on energy use and thermal comfort inside buildings. This paper first presents a study of changes in energy demand in residential buildings considering the overlapping effect of climate change and urban heat island intensity in two European locations; Cadiz (Spain) and London (United Kingdom), representing temperate and hot European climates and moderate and dense urban settings. Future-urban weather files were generated and simulations were run considering energy demand and indoor thermal comfort. In hot climate regions such as the one of Cadiz, future climate will increase the cooling demand and the additional impact of the UHI leads to a further increase of up to +28% of total energy demand compared to the current climate without considering urban effects. Future-urban weather conditions will be detrimental also for buildings in London, where the annual energy demand is predicted to increase by up to the 16% if future climate and urban effects are included. This is due to a higher increase in cooling demand compared to the reduction for the heating need. The paper also presents a method to take into account microclimatic conditions in naturally ventilated buildings, especially the effect of wind variations around the building which impacts natural ventilation rates. Air and surface temperature and wind speeds were studied using ENVImet and the resulting microclimatic conditions were used as inputs to the EnergyPlus Airflow Network model for the calculation of the building ventilation rates. It was found that ventilation rates are reduced (in comparison to meteorological weather files) and this reduction impacts negatively on internal operative temperatures. A thermal comfort analysis was carried out indicating that the selection of a suitable weather file and microclimatic conditions is essential for more accurate predictions of internal thermal comfort and will assist in the sizing of passive and active systems to avoid overheating.

How is commute mode choice related to built environment in a high-density urban context?

Mainstream studies on the relationship between built environment and travel behavior have mostly concerned about relatively low-density urban contexts in North American and European countries. Using Hong Kong as such a case, this study addresses the unique challenges and problems associated with this topic in extremely dense urban settings. In addition to investigating how built environment features are related to the choices between public transport and cars, we also divide public transportation into three sub-modes to study the impacts of built environment. Furthermore, we test how these relationships differ between millennials and older generations. Results indicate that built environment characteristics are more influential in people's choices among different public transport sub-modes than in their choice between public transport and cars. Compared to older commuters, millennials' choices of rail-based and mixed-mode public transport are more susceptible to built environment attributes whereas their effects on road-based transit usage are stronger for older commuters. These investigations provide important insights into individuals' commute mode choices in highly dense, transit dominated urban contexts, and hence provide more reliable grounds for policymaking in these cities to encourage the usage of specific public transit sub-modes, as well as to meet the needs of different age groups.

Tree Information Modeling: A Data Exchange Platform for Tree Design and Management

Trees integrated into buildings and dense urban settings have become a trend in recent years worldwide. Without a thoughtful design, conflicts between green and gray infrastructures can take place in two aspects: (1) tree crown compete with living space above ground; (2) built underground environment, the other way round, affect tree’s health and security. Although various data about urban trees are collected by different professions for multiple purposes, the communication between them is still limited by unmatched scales and formats. To address this, tree information modeling (TIM) is proposed in this study, aiming at a standardized tree description system in a high level of detail (LoD). It serves as a platform to exchange data and share knowledge about tree growth models. From the perspective of architects and landscape designers, urban trees provide ecosystem services (ESS) not only through their overall biomass, shading, and cooling. They are also related to various branching forms and crown density, forming new layers of urban living space. So, detailed stem, branch and even root geometry is the key to interacting with humans, building structures and other facilities. It is illustrated in this paper how these detailed data are collected to initialize a TIM model with the help of multiple tools, how the topological geometry of stem and branches in TIM is interpreted into an L-system (a common syntax to describe tree geometries), allowing implementation of widely established tree simulations from other professions. In a vision, a TIM-assisted design workflow is framed, where trees are regularly monitored and simulated under boundary conditions to approach target parameters by design proposals.

Learning multi-agent cooperation.

Advances in reinforcement learning (RL) have resulted in recent breakthroughs in the application of artificial intelligence (AI) across many different domains. An emerging landscape of development environments is making powerful RL techniques more accessible for a growing community of researchers. However, most existing frameworks do not directly address the problem of learning in complex operating environments, such as dense urban settings or defense-related scenarios, that incorporate distributed, heterogeneous teams of agents. To help enable AI research for this important class of applications, we introduce the AI Arena: a scalable framework with flexible abstractions for associating agents with policies and policies with learning algorithms. Our results highlight the strengths of our approach, illustrate the importance of curriculum design, and measure the impact of multi-agent learning paradigms on the emergence of cooperation.

Role of Azadirachta indica (Neem) and Polyalthia longifolia (Asopalav) trees for improving outdoor thermal environment in unorganized urban settings

This study assesses the effect of native trees inimproving the outdoor thermal environment of an educational institute located in the semi-arid city of Ahmedabad, India. The study area was modelled using ENVI-met and validated against the field measurements. Physical properties of 8 species (55 samples) found in the city were collected. Azadirachta indica (Neem) and Polyalthia longifolia (Asopalav) are among the top 10 species found in the city. The campus has limited space availability and green cover, hence adding more trees is not possible. Hence, two separate scenarios ofonly those two specieswere developed by replacing the existing trees. The reduction in air temperature, mean radiant temperature and physiological equivalent temperature (PET) against existing scenario by Asopalav trees at a non-shaded site was found to be up to 1.0°C, 2.2°C and 2.0°C whereas by Neem trees was found to be up to 1.1°C, 2.3°C and 2.1°C. This similarity was likely due to their similar crown widths. The attenuation of direct short-wave radiation by Neem trees was more due to higher Leaf Area Density (LAD). Trees with higher LAD and wider crowns are found to be more useful in improving the outdoor thermal environment in dense urban settings with space constraints.

Modeling factors contributing to dockless e-scooter injury accidents in Austin, Texas

Objective Over the past few years, increased e-scooter ridership has raised concerns about the growing number of injury accidents involving e-scooters. Additionally, given the lack of appropriate e-scooter accident data, the extent to which built environment and socioeconomic factors affect e-scooter safety is unclear. In consideration of these issues, this study was aimed at identifying the factors contributing to the number of e-scooter injury accidents in Austin. Methods We developed zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models on the basis of 2018 dockless e-scooter injury accident data collected from the Patch platform. The results indicated that the ZIP model better fit the accident data. Results Significant variables included the ratio of 18- to 34-year-old males to their female counterparts, the median annual household income (in thousands), the ratio of public transport users to private transport users, the land use entropy index, the percentage of restaurants, and the percentage of educational centers in the study site. Conclusions As e-scooter accidents are likely to occur in dense urban settings, a critical initiative is to develop new infrastructure, such as bike lanes, and/or extend sidewalks beyond core urban areas. Another highly recommended measure is to implement a demerit point system for the suspension of riders who engage in unsafe behaviors. Lastly, launching educational campaigns by e-scooter operators and law enforcement agencies will raise riders’ awareness about road and personal safety.

Sanctuary Cities in Europe? A Policy Survey of Urban Policies in Support of Irregular Migrants

AbstractIrregular migrants tend to live in dense urban settings. Cities therefore formulate various policies in support of irregular migrants. Given the US phenomenon of sanctuary cities, the study of these policies has been rather US-centric so far. This letter examines urban policies in support of irregular migrants in Europe's 95 largest cities. Only 27 per cent of European cities formulate these types of policies. We discovered two relevant policy categories: status and services. Only five cities formulate policies that aim to award irregular migrants with a (more) secure status, and 24 cities formulate policies that facilitate access to city services. Our mixed-methods analysis suggests that status policies take advantage of policy-making discretion whereas service policies hinge on the availability of local resources. Yet, there are no simple explanations for the observed policy diversity that is the product of place-based policy-making.

Modeling Natural Light Availability in Skyscraper Farms

Lighting is a major component of energy consumption in controlled environment agriculture (CEA) operations. Skyscraper farms (multilevel production in buildings with transparent glazing) have been proposed as alternatives to greenhouse or plant factories (opaque warehouses) to increase space-use efficiency while accessing some natural light. However, there are no previous models on natural light availability and distribution in skyscraper farms. This study employed climate-based daylight modeling software and the Typical Meteorological Year (TMY) dataset to investigate the effects of building geometry and context shading on the availability and spatial distribution of natural light in skyscraper farms in Los Angeles (LA) and New York City (NYC). Electric energy consumption for supplemental lighting in 20-storey skyscraper farms to reach a daily light integral target was calculated using simulation results. Natural lighting in our baseline skyscraper farms without surrounding buildings provides 13% and 15% of the light required to meet a target of 17 mol·m−2·day−1. More elongated buildings may meet up to 27% of the lighting requirements with natural light. However, shading from surrounding buildings can reduce available natural light considerably; in the worst case, natural light only supplies 5% of the lighting requirements. Overall, skyscraper farms require between 4 to 11 times more input for lighting than greenhouses per crop canopy area in the same location. We conclude that the accessibility of natural light in skyscraper farms in dense urban settings provides little advantage over plant factories.

Urban Ecological Restoration: Setting Priorities for Restoring Native Vegetation in Lava Field Remnants in Mexico City

As cities overgrow, the need for ecological restoration is becoming increasingly urgent, especially in densely populated areas. Urban ecological restoration represents the best approach to undertake damages to restore native ecosystem remnants fulfilling biodiversity but also social goals in dense urban settings such as Mexico City. The feasibility of restoring unique xerophytic scrub vegetation in lava field remnants was evaluated in a portion of a university campus in Mexico City. Here we present an index (Need and Feasibility of Restoration Index, NFRI) for such purpose. The NFRI was designed through multicriteria analysis and considered ecological, economic, and social indicators. Cluster and principal components analysis were carried out to identify different groups of lava field remnants with similar characteristics and to point out critical variables that in turn would support management strategies. The outcomes made evident the necessity of restoring native vegetation for all of the evaluated remnants; however, the group containing the largest ones obtained the highest values for restoration feasibility and NFRI. The recovery of the rest of the remnants is critical to support the ecological restoration of the area as this may provide connectivity with better-preserved ecosystem remnants. When the restoration is unaffordable due to financial constraints, it is highly recommended to direct efforts towards ecological rehabilitation actions. The establishment of native xerophytic gardens is promoted when remnants cannot support a self-sustainable plant community. It is crucial to include the diversity of views and values of the community and the economic and ecological aspects to guarantee the sustainability of the landscape, especially in the urban context. The latter can provide better planning and design processes, ensuring benefits for humans and nature.