Urban Sci., Volume 9, Issue 11 (November 2025) – 10 articles

Monitoring nitrate levels in water is critical to protect public health and ensure compliance with regulatory standards. This study provides a comprehensive evaluation of four analytical techniques—test strips, ion-selective electrodes (ISE), colorimetric methods, and titration—to assess nitrate levels in a variety of water sources, including standard solutions, rainwater, bottled water, and groundwater from both shallow and deep wells located in semi-urban regions of Saudi Arabia. Each method was assessed for sensitivity, accuracy, detection limits, reproducibility, and operational practicality. Test strips offer rapid, low-cost screening but consistently underestimate nitrate concentrations, particularly at low levels. The ISE demonstrated broad applicability and reliable performance across a wide concentration range when properly calibrated, making it suitable for both field and laboratory applications. Colorimetric methods provide excellent sensitivity for trace-level detection, whereas titration delivers the highest accuracy for high-nitrate samples despite its time-intensive nature. By calibrating and validating the methods against certified standards, we quantitatively demonstrated their reliability through statistical measures such as precision and accuracy rates. Moreover, the application of Geographic Information System (GIS) techniques in spatial analysis has revealed significant differences in the distribution of nitrates. Notably, shallow wells located in the northern regions surpass the 50 mg/L limit set by the World Health Organization (WHO), thereby indicating the presence of localized contamination hotspots. This study is among the first to systematically compare nitrate detection methods across a wide range of water types in a semi-urban area of Saudi Arabia. Building on a detailed analysis of each method, we underline the crucial need for the strategic selection of nitrate analysis techniques. This selection should be tailored to specific operational contexts, accuracy requirements, and concentration ranges to guide stakeholders towards more informed decision-making. These findings provide actionable guidance for public health officials and water managers to prioritize monitoring, safeguard drinking-water sources, and mitigate nitrate-related health risks in semi-urban communities. Full article

The transition to sustainable urban mobility requires innovative solutions optimising electric vehicle (EV) ecosystems while integrating seamlessly with smart urban grids. This paper proposes a decentralised framework leveraging adaptive algorithms, vehicle-to-grid (V2G) technology, and renewable energy prioritisation to enhance urban sustainability without requiring new infrastructure. By integrating federated learning (FL) for privacy-preserving coordination, multi-objective optimisation for load balancing, and predictive models for renewable energy integration, our approach addresses energy demand, grid stability, and environmental impact in urban areas. Validated through simulations on an IEEE 39-bus urban feeder and real-world urban mobility case studies, the framework achieves a 40% reduction in carbon emissions, improves grid reliability by 20%, and enhances renewable utilisation by 25% compared to an uncoordinated charging baseline. These outcomes support urban planning by informing smart grid design, reducing urban heat island effects, and promoting equitable mobility access. This work provides actionable strategies for policymakers, urban planners, and energy providers to advance more sustainable, electrified urban ecosystems. Full article

Areas with well-developed networks of equestrian routes attract riders, contributing to tourism development and boosting the economy. As the most critical elements of equestrian routes are road, railway, and watercourse crossings, the construction of bridges and underpasses that meet equestrian needs is crucial. Due to the lack of clear, standardised guidance for the design of equestrian bridges and underpasses, a systematic literature review was conducted to identify and select manuals deal with equestrian bridge and/or underpass design. The selection criterion required that the manual be currently valid, written in English, and published online with open access, ensuring easy accessibility for engineers and policymakers. This paper summarises, compares, and comments on the design parameters of equestrian bridges and underpasses listed in the analysed manuals, which must be considered to achieve optimal solutions for both horse and rider. It also provides an overview of general recommendations and best practices for specific design parameters. In the absence of a manual offering comprehensive, standardised guidelines for the design of equestrian bridges and underpasses, this paper may assist policymakers, developers, and designers in creating a trail network suitable for equestrians. Full article

Sport events generate economic, social, and environmental impacts that shape residents’ perceptions and levels of support. In the context of sustainable urban development, understanding how residents evaluate these impacts provides valuable knowledge about community responses to tourism and event-led growth. Drawing on the Triple Bottom Line (TBL), Social Exchange Theory (SET), and Social Representations Theory (SRT), this study examines residents’ evaluations of the Rally Sierra Morena (RSM), a large-scale international motorsport event recently incorporated into the European Rally Championship (ERC). Data were collected shortly before the event using a self-administered questionnaire (n = 1529). An exploratory factor analysis (EFA) identified a multidimensional structure of perception, and a non-hierarchical k-means cluster analysis identified three clusters: Skeptics, who perceived stronger negative than positive impacts in economic and environmental dimensions; Pragmatists, who emphasized positive economic benefits while acknowledging environmental costs; and Enthusiasts, who consistently rated positive impacts higher across all dimensions and expressed the strongest support for the event. By integrating perceptual and sustainability-based approaches, this study connects residents’ evaluations of a motorsport event with broader discussions on urban resilience and sustainable community development. Full article

Balconies are widely recognized for enhancing urban livability, making them attractive elements to incorporate in building renovation projects. However, their impact on energy performance remains insufficiently studied, particularly in temperate climates, like the Mediterranean, where both heating and cooling demands must be considered. This article evaluates the energy impacts of integrating open balconies into housing retrofits on the space conditioning demand of dwellings through spatialized analysis at the urban block scale. Focusing on Barcelona’s Eixample district, a parametric Urban Building Energy Modeling (UBEM) was employed to assess how balcony design interacts with urban morphology (orientation, obstructions), building features (window-to-wall ratio, WWR), and balcony length. Results reveal a seasonal trade-off at the block scale: balconies increase heating demand (0.1–1.6 kWh/m²·yr) by reducing winter solar gain but decrease cooling demand (0.1–3.8 kWh/m²·yr) through summer shading. Net effects vary by unit position, with south-facing and moderately glazed dwellings benefiting the most. Deeper balconies (1.5–2 m) amplify both effects, while optimal depth depends on the window-to-wall ratio. Under future climates, retrofits combining insulation and balconies mitigate rising cooling demands more effectively than insulation alone, reducing block-level demand by up to 16%. Although balconies alone show modest energy savings at the block scale, they enhance localized thermal resilience. The study highlights the need for integrated retrofit strategies that balance thermal insulation with solar protection to address both current and future energy challenges while enhancing occupant well-being. Full article

The growth of e-commerce has imposed new challenges on urban supply chains, especially in the middle mile, which still lacks structured, sustainable and scalable logistics solutions. This study investigates the feasibility of using the Bus Rapid Transit (BRT) system, widely present in cities of emerging economies, as an urban logistics platform for the transport of light and traceable goods. This research adopts a qualitative approach, with analysis of international experiences and development of a methodological framework based on three main components: technical, economic and governance. The results reveal that the use of idle operating windows, load compatibility and institutional articulation are key factors for the implementation of the system. The proposal represents a logistical innovation aligned with the new paradigms of urban resilience and the multifunctionality of public infrastructure. This study suggests that BRT could serve as a potential logistics platform for the middle mile, under specific operational and governance conditions. Full article

Understanding how environmental design and institutional trust shape perceived security in nightlife settings is essential for enhancing customer experiences and business sustainability. This study examines how surveillance, access control, territoriality, maintenance, and trust in police influence customers’ perceptions of security in nightlife establishments in Colombia, and how these perceptions affect satisfaction and revisit intentions. A survey was conducted involving 400 customers in nightlife venues in Guadalajara de Buga, using Likert scales to evaluate the constructs. Data were analyzed using partial least squares structural equation modeling; Results indicate that maintenance (β = 0.304), surveillance (β = 0.264), trust in police (β = 0.203), and territoriality (β = 0.184) significantly influence perceived security, while access control does not. Perceived security strongly impacts satisfaction (β = 0.662) and revisit intention (β = 0.641). The model explains 47% of the variance in perceived security, 43% in satisfaction, and 41% in revisit intention. These findings highlight the value of integrating environmental design and institutional trust within service marketing and crime prevention, showing that investments in design and maintenance can yield commercial benefits. The study offers guidance for owners seeking to improve customer satisfaction and loyalty through targeted strategies. Full article

Infrastructure asset management faces major challenges in maintaining ageing assets while adapting to technological changes and budget constraints. This paper addresses the lack of a clear definition for “operations and maintenance (O&M) capability” in the context of infrastructure asset management. The authors conducted a systematic literature review extracting 13 capability definitions across multiple domains, followed by semi-structured interviews with 11 senior industry experts from diverse infrastructure sectors, analysing data through List–Group–Label methodology. The research resulted in a comprehensive yet practical definition of O&M capability and identified its key components through an expert-refined framework that balances comprehensiveness and simplicity. This definition provides practitioners and researchers with a common understanding that enables better adaptation of infrastructure to rapid technological change, better utilisation of data and a stronger focus on citizen needs. The framework enables cities and infrastructure operators to systematically assess, develop, and communicate their O&M capabilities, supporting standardised approaches to capability planning and performance measurement across smart city infrastructure projects. The framework creates a foundation for future research and practical applications in O&M and stimulates further development of approaches to build capabilities for smart city infrastructure. Full article

The Moroccan Ryad, a cherished architectural treasure in North Africa, symbolizes cultural richness and architectural legacy. This paper advocates an inventive strategy to preserve and rejuvenate the Ryad as an energy-efficient model, intertwining modern sustainability principles. Employing a multidisciplinary approach, this study delves into the fusion of traditional Ryad design with contemporary sustainability, tackling energy efficiency, resource conservation, and cultural heritage challenges. Examining historical construction methods, material choices, and spatial arrangements alongside sustainable building practices, this paper showcases case studies of newly constructed sustainable Ryads. These examples spotlight strategies like passive solar design, renewable energy incorporation, water conservation, and local material use, augmenting energy performance while fostering cultural continuity through eco-friendly materials and traditional craftsmanship. This research also explores the social and economic impacts of this sustainable Ryad model, including its potential to boost tourism, generate employment, and engage communities. Additionally, it addresses the role of public policy in supporting sustainable practices for preserving Moroccan cultural heritage. By amalgamating culture, sustainability, and energy efficiency, this paper envisions a new role for the Moroccan Ryad, positioning it not only as a guardian of heritage but also as a symbol of environmentally responsible architecture—a model applicable to culturally rich regions globally. Full article