Search Results (4,950)

As essential components of the natural environment, urban green and blue spaces (UGBSs) hold significant potential to enhance public health and wellbeing. However, existing research is limited in understanding the spatiotemporal heterogeneity and nonlinear relationships characterizing how built environment (BE) features of UGBSs influence public happiness. This study takes Nanjing, China as a case study. It integrates multisource data (e.g., social media text, remote-sensing imagery, POI data, land use, etc.) and employs machine learning techniques (including sentiment analysis and random forest), to investigate the nonlinear effects and spatiotemporal dynamics of UGBSs’ BE on public happiness. The results show that nonlinear relationships (e.g., S-shaped and inverted U-shaped) commonly exist between UGBSs’ BE indicators and happiness. The influence of UGBSs’ BE on happiness demonstrates significant spatiotemporal dynamics. Diversity and destination accessibility were dominant factors from 2021 to 2023, whereas the importance of the design and density dimensions increased substantially after 2023. The influence varied across UGBS types; except for the diversity dimension, the BE’s density, design, and destination accessibility were significantly associated with happiness across all UGBS types. The study offers empirical evidence to inform planning and management of UGBS infrastructure, with the aim to maximize public health benefits and foster healthy cities. Full article

Most established street-vitality assessment tools were developed in temperate, predominantly Western urban settings and therefore do not adequately capture the climatic and socio-spatial conditions of hot–arid cities. This study develops and validates the Resident-Centered Street Vitality Framework (RCSVF) using Riyadh as a case study representative of the Arabian Desert urban context. Drawing on a cross-sectional quantitative design, the research integrates a resident survey across nineteen neighborhoods (N = 1102), physical observations of 133 street segments, a visual preference survey (N = 418), and GIS-based spatial analysis. The results reveal marked intra-urban inequality in perceived environmental quality and demonstrate that service proximity is a substantially stronger predictor of residential satisfaction than street physical quality alone. Residents consistently rated shading, green space, and pedestrian infrastructure as the weakest dimensions of their neighborhoods. These findings indicate that street vitality in hot–arid settings cannot be validly assessed through imported observer-based metrics. A resident-centered, climate-responsive framework is required to capture how thermal exposure, functional accessibility, and everyday social use interact in shaping street experience. Full article

Boosting urban vitality (UV) in residential living spaces has become a core component of advancing the people-centered urbanization strategy. However, previous research has mainly focused on exploring UV at the scales of streets, blocks, and grids, with few nonlinear explorations conducted across different temporal dimensions at the scale of residents’ daily life. Therefore, this article adopts the XGBoost-SHAP model to explore the nonlinear and interaction effects of a built environment (BE) on UV across multi-scale community life circles (CLC), distinguishing between daytime and nighttime on weekdays and weekends. The results indicate that UV on weekends is higher than on weekdays, except for 5 min CLC (5MCLC). UV is highest in 10 min CLC (10MCLC) and lowest in 5MCLC. The mean building height (MBH) and Normalized Difference Vegetation Index (NDVI) have always been the most important indicators affecting UV. Unlike previous studies, the green view index (GVI) and sky view factor (SVF) are negatively associated with UV. The nonlinear relationship between BE and UV on weekdays exhibits greater regularity. The effects of other BE indicators on UV exhibits spatiotemporal heterogeneity, with the relative influence changes in commercial accessibility (CA), distance to metro (DSM) and distance to bus (DSB) being the most significant. The nonlinear and threshold effects of BE on UV show significant changes, except for GVI, SVF, and NDVI, at different times and scales. The threshold for cultural and leisure accessibility (CLA) is higher on weekdays than on weekends, whereas that for DSM is higher on weekends than on weekdays. The interaction effects between the building density (BD) and MBH, park and square accessibility (PSA), and DSM is significant at different scales. This study will provide a scientific basis for optimizing BE and differentiated planning of CLC, which further contributes to enhancing UV and promoting urban sustainable development. Full article

This paper addresses the problem of automated segmentation of plant green biomass in field crop images aimed at improving the accuracy of crop and weed identification. To construct a training dataset for neural network models, an automatic annotation algorithm is proposed, enabling the generation of polygonal object masks without human intervention. The method is based on adaptive analysis of color characteristics of plant fragments with iterative narrowing of the hue range in the HSV color space, combined with an integral quality metric that accounts for the dynamics of contour area and shape. The proposed method achieved an IoU of 93.22% and a DSC of 96.30%, demonstrating a high level of agreement between automatic and manual annotations. The generated masks are used to train segmentation models of the YOLO11-seg family. Models of different scales (n, s, m, l, x) were trained and evaluated using standard metrics, including Intersection over Union (IoU), mAP@0.5, mAP@0.5–0.95, F1-score, and Precision–Recall (PR) curves. Experimental results demonstrate that models trained on automatically generated annotations achieve stable segmentation performance of plant green biomass. The best results were obtained with the YOLO11m-seg model, achieving an F1-score of 0. 772. The results confirm the effectiveness of the proposed approach and demonstrate acceptable segmentation quality, supported by both quantitative metrics and visual analysis. The developed automatic annotation algorithm can be used to expand training datasets in computer vision tasks for agricultural applications. Full article

Urban emptiness is a recurring spatial condition across contemporary cities, resulting from long-term planning decisions, functional transformations, and shifting socio-economic dynamics. Urban voids are often interpreted as signs of failure or neglect; however, they also represent flexible and open-ended spaces embedded within everyday urban environments. This study develops and tests the Adaptive Void Assessment Framework (AVAF), a five-dimensional typological instrument applied to n = 33 urban voids identified through a systematic grid-based field survey (100 × 100 m resolution) in the central urban zone of Nitra, Slovakia (March 2025–January 2026). The framework evaluates sites across nine indicators spanning openness, social appropriation, ecological succession, temporal persistence, and institutional flexibility, yielding composite Adaptivity Index scores and four dominant adaptive regimes. The findings demonstrate that 34% of identified voids function in a socially active regime while 14% exhibit ecological dominance, with a moderate positive correlation identified between temporal persistence and adaptive capacity (r = 0.46, p < 0.05). This challenges conventional deficit-based classifications and reframes urban voids as active components of the urban metabolism capable of enhancing ecological connectivity and spatial flexibility within post-industrial urban landscapes. This reframes urban voids from residual outcomes of urbanization to spaces with potential for green integration within sustainable contemporary cities. Full article

The decarbonization of urban public transport requires robust tools to evaluate the operational feasibility and energy implications of bus electrification. This study presents a physics-based modeling framework for estimating the energy consumption of urban bus operations using real-world telemetry data. GPS measurements collected onboard operating buses are used to reconstruct vehicle speed profiles and driving dynamics. The methodology is applied to a representative urban bus route operating in the city centre of Milan, characterized by dense traffic, closely spaced stops, and a high density of signalized intersections. Two operational improvement scenarios are investigated: traffic signal coordination through a “green wave” strategy and the integration of opportunity flash charging (OC) at selected stops. The results show that reducing traffic-related stops improves commercial speed and decreases energy demand, while OC can support battery operation within the constraints of urban service conditions. The proposed framework provides a transferable decision-support methodology for transit agencies planning the electrification of urban bus services and the deployment of supporting infrastructure. Full article

Recreational vitality is widely recognized as a core metric for assessing the quality of human settlements. Elucidating the relationship between recreational vitality and landscape characteristics is crucial for guiding the optimization and quality enhancement of urban waterfront spaces. This study takes the micro-scale waterfront space of the Beijing–Hangzhou Grand Canal (Hangzhou section) as its research object, systematically analyzes the correlation between waterfront landscape attributes and recreational vitality, and formulates specific optimization strategies for enhancing recreational vitality. A total of 310 representative sampling sites was established. The study integrates machine learning-driven semantic image segmentation to achieve refined quantification of waterfront landscape metrics and employs anonymized mobile phone signaling data to dynamically characterize the spatiotemporal distribution of recreational vitality. Through correlation analysis and regression modeling, it quantifies the effect size and functional mechanisms of key landscape metrics on recreational vitality, and further proposes adaptive strategies for recreational vitality enhancement tailored to different urban functional zones. The key findings are as follows: (1) Recreational vitality is significantly higher on holidays than on workdays. High-vitality areas are concentrated in commercial functional zones, with an overall spatial gradient of “low in the east and high in the west, low in the north and high in the south”. (2) High-level Green View Factor (HGVF) shows a stable positive correlation with vitality, whereas the Sky View Factor (SVF) and the Enclosure Interface View Factor (EIVF) correlate negatively. (3) The influence of landscape metrics is strongly moderated by functional zone type: in residential functional zones, HGVF has strong explanatory power; in commercial functional zones, it shows complex nonlinearity; in ecological conservation zones, its explanatory power is generally weaker. (4) Tailored enhancement strategies are proposed for each functional zone. This study clarifies the link between core waterfront landscape attributes and micro-scale recreational vitality, and provides a scientific basis for evidence-based design and sustainable enhancement of urban waterfront spaces. Full article

Tree rings record environmental conditions and can serve as long-term biomonitors of urban pollution. This study evaluated the radial growth and chemical composition of Pinus greggii wood in three urban green areas of Mexico City: San Juan de Aragón Park (SJA), Sierra de Guadalupe State Park (GUAD), and Vivero Coyoacán National Park (COY). Tree ring chemical elements were analyzed at annual resolution for the period 2002 to 2022, and their relationships with atmospheric pollutant concentrations, including nitrogen oxides (NO_x), carbon monoxide (CO), ozone (O₃), and particulate matter (PM), of medium size or smaller than 10 µm, including the fractions PM_2.5 and PM₁₀, were assessed using a spatial scaling approach. Elemental concentrations were determined using X-ray fluorescence (XRF). Statistical analyses included analysis of variance (ANOVA), Theil–Sen trend estimation, and Pearson correlation with lag analysis (up to 3 years). The oldest trees were recorded in COY (52 years), while the youngest were recorded in GUAD (13 years). Distinct temporal patterns in elemental concentrations were detected among sites; for instance, peak concentrations of Fe (307 ppm), Cu (11 ppm), and Zn (51 ppm) occurred in GUAD in 2021, while Pb concentrations declined during 2019–2020 across all three sites. Significant correlations (p < 0.05) were identified between Cu, Fe, Zn, and Pb and the atmospheric pollutants (NO_x, PM_2.5, PM₁₀, O₃). Notably, O₃ showed significant positive correlations with Fe at SJA (up to r = 0.80) and GUAD (up to r = 0.46) with lags ranging from 0 to 3 years, suggesting delayed responses between atmospheric pollution and elemental deposition in tree rings. These findings highlight the sensitivity of P. greggii to urban atmospheric pollution and support its potential as a long-term biomonitoring tool, as well as its importance for informing policies aimed at improving air quality and promoting the sustainable management of urban green spaces. Full article

Continuous urban expansion and the resulting land use and land cover (LULC) changes significantly exacerbate the urban heat island effect and intensify heatwaves. While the cooling effects of blue–green spaces are widely documented, most studies focus on single landscape types or specific time frames. Few investigations systematically explore the comprehensive thermal regulation mechanisms of gray–green spaces, or their nonlinear driving factors and interactive effects across coupled seasonal and diurnal scales. To address these gaps, this study focuses on Chengdu, a typical expanding city in China, to establish a comprehensive indicator system for urban gray–green spaces. This system encompasses four key dimensions: coverage, fragmentation, aggregation, and morphological spatial pattern. After evaluating 12 machine learning models, the optimal model was selected for further analysis using SHapley Additive exPlanations (SHAP) and Partial Dependence Plots (PDP). This research investigates the nonlinear thresholds and interactive effects of composite gray–green space indicators on land surface temperature (LST) across varying seasonal and diurnal cycles. The results indicate that: (1) The impact of gray–green spaces on LST varies significantly across seasonal and diurnal contexts. Green spaces primarily exert a cooling effect during spring, summer, and autumn, whereas gray spaces dominate heat retention during winter and across all nocturnal periods. (2) The morphological spatial pattern of green spaces (GMSPA) outperforms traditional coverage indicators (G1) in providing cooling benefits across multiple scenarios. (3) The cooling efficiency of GMSPA peaks between −0.8 and −0.5, reaching saturation at 0.53. Conversely, LST exhibits a sharp, step-like increase when gray space aggregation (B3) exceeds −0.58. (4) Optimizing areas with high GMSPA can significantly mitigate heat exposure risks in expanding cities. These findings offer robust theoretical insights and actionable guidelines for spatial planning aimed at thermal resilience, urban thermal environment management, and building energy conservation in rapidly growing urban areas. Full article

The Research and Observation in Medium Earth Orbit (ROMEO) mission, developed at the University of Stuttgart‘s Institute of Space Systems, seeks to demonstrate a cost-effective exploitation of the medium Earth orbit (MEO) for sustainable access to space. It uses a green propulsion system with water as propellant to reach up to 2500 km altitude starting from a 450 km sun-synchronous orbit (SSO). This paper presents the design and intended use of the ROMEO satellite as well as its two in-house developed camera systems, the public relations (PR) and the near-infrared (NIR) camera system. The PR camera system features two silicon sensors with a Bayer color pattern in a compact, lightweight package and in a cold redundant setup to reduce the impact of radiation-related degradation. Their wide field of view (128 × 96°) allows imaging of the complete visible Earth in the mission‘s final orbit and supports calibration of the Earthshine telescope, which is the primary payload. The NIR camera system uses a commercial InGaAs sensor with a high quantum efficiency up to 1700 nm, coupled to a 100 mm focal length optics assembly that yields a ground sampling distance of 45 m in the initial orbit. Its scientific objectives include monitoring gas flares and wildfires, which are relevant to climate change research, and demonstrating an exoplanet transit detection—an unprecedented capability for a small satellite using a commercial off-the-shelf InGaAs sensor in the NIR spectrum. This paper demonstrates that ROMEO’s compact, low-mass camera systems meet mission constraints while enabling a broad spectrum of scientific and outreach activities. Full article

In rapidly urbanizing metropolitan areas, children increasingly face risks to their physical and mental health, largely due to constrained access to suitable outdoor spaces that support regular physical activity. The uneven distribution and varying quality of these urban outdoor environments further intensify such risks by limiting children’s opportunities for safe, stimulating, and health-promoting activities. However, the existing research often lacks a systematic framework to quantify these spatial inequities across multiple dimensions. This study aims to fill this gap by constructing a robust analytical framework for evaluating outdoor environmental quality. It quantifies spatial distribution and determinants of these inequalities. The framework is structured around four core dimensions: Safety, Facility Variety, Fun, and Greenness. Taking Beijing as a case study, data from 1598 primary and secondary schools were analyzed. The Gini coefficient and Moran’s I were used to evaluate the equality and spatial clustering of environmental indicators, while the Geographically Weighted Regression model explored how Spatial Construction, Social Development, and Economic Level shape environmental quality. The results reveal the following findings: (1) the quality of children’s outdoor physical activity environments in Beijing is notably unequal, especially regarding Greenness and Fun; (2) these disparities correspond closely to the city’s “core–periphery” metropolitan structure; and (3) the relationships between metropolitan-level factors and environmental quality exhibit strong spatial heterogeneity. This study provides a comprehensive framework for evaluating and visualizing inequalities in children’s outdoor environments, offering empirical support for inclusive and health-oriented urban governance. Full article

Forest areas may represent an important component of everyday urban environments, yet evidence remains mixed regarding whether perceived proximity and actual use show similar associations with health-related outcomes. Using a cross-sectional descriptive–correlational design, this study examined associations of perceived stress and self-rated health with perceived walking access to the nearest forest, residential green view, visit frequency, and visit duration among adults living in İstanbul, Türkiye. The study included 345 adults aged 18 years and older; complete PSS-14 data were available for 332 participants. In bivariate analyses, older age was associated with lower perceived stress, whereas longer perceived walking time was associated with higher perceived stress. Greater residential green view, more frequent visits, and longer visit duration were associated with lower perceived stress. For self-rated health, only visit frequency showed a significant bivariate association. In adjusted analyses, visit frequency remained independently associated with lower PSS-14 scores, whereas green view showed a borderline inverse association. In the ordinal logistic regression model, female sex was associated with higher odds of reporting worse self-rated health, while visit frequency and green view remained borderline. These findings indicate modest associations, with the clearest pattern observed for visit frequency and perceived stress. Given the convenience-sample design, self-reported exposure measures, and low model explanatory power, the findings should be interpreted as correlational and hypothesis-generating rather than causal. Full article

Urban canyons, integral components of the built environment, significantly influence microclimatic conditions and thermal comfort. This review investigates their combined effects with green infrastructure on thermal comfort, offering a comprehensive framework for supporting urban design and greening strategies. The review is based on a structured literature analysis of peer-reviewed studies retrieved from major scientific databases (Scopus and Web of Science), following defined selection and screening criteria. Urban canyon orientation determines solar exposure and its interaction with prevailing wind patterns, affecting ventilation and heat dissipation. The urban canyon aspect ratio influences shading and airflow regulation, while their sky view factor moderates radiative cooling and daylight availability. Urban greening—encompassing street trees, green roofs, and vertical green walls—complements urban geometry by reducing air temperatures, enhancing evapotranspiration, and modifying local wind dynamics. Tree shading can reduce the physiological equivalent temperature in urban canyons, mitigating extreme heat stress. Key vegetative parameters, such as leaf area index and canopy density, are critical for quantifying cooling contributions. Key findings underscore the role of higher aspect ratios in enhancing shading and ventilation while they emphasize the critical influence of street orientation and sky view factor on microclimatic regulation. Vegetation emerges as a vital component, with tree shading contributing substantially to cooling effects and reducing physiological equivalent temperature. The beneficial synergistic interaction between urban geometry and vegetation optimizes thermal comfort. Tailored strategies based on urban canyon typologies balance urban development with environmental sustainability. The proposed framework provides actionable strategies for designing resilient and thermally optimized urban spaces, promoting climate-adaptive urban planning by addressing the dual challenges of the urban heat island and thermal discomfort in cities. Full article

This study developed a comprehensive framework integrating ecosystem services (ESs), ecological adaptability, and ornamental value to guide tree species selection in historic cities constrained by soil salinization and subsurface heritage conservation. Taking Kaifeng, Henan Province, as a case study, we employed field surveys, i-Tree Eco, the Analytic Hierarchy Process, and K-means clustering to evaluate trees across protective, park, attached, and square green spaces. Results showed that carbon-related services dominated Kaifeng’s urban ES profile, with carbon storage (CS) and sequestration (CSE) value densities of 9.09 ¥·m⁻² and 0.84 ¥·m⁻²·y⁻¹, respectively. Air pollutant removal (AR) (0.21 ¥·m⁻²·y⁻¹) and P (0.009 ¥·m⁻²·y⁻¹) values remained comparatively low. Camphora officinarum Nees ex Wall delivered the highest annual ES value per tree (33.24 ¥·y⁻¹). Plaza greenery outperformed other space types in overall service provision, and deciduous broadleaf species generated greater ES value than evergreen conifers. Cluster analysis identified four functional groups: stress-tolerant pioneers, balanced adapters, high-efficiency carbon sinks, and ornamental specialists—each suited to specific green space contexts. This integrated framework offers a transferable approach for evidence-based tree selection in saline historic cities, supporting nature-based solutions in urban green space (UGS) planning. Full article

Urban nature and nature-based solutions are increasingly promoted to enhance public space experience and urban climate resilience. In Public and semi-public indoor settings, biophilic design is considered beneficial for stress reduction and mental health restoration through the introduction of natural elements such as plants. However, research focusing on the specific visual features of plants and the underlying mechanisms remains limited. Based on 200 indoor greenery images and their multi-dimensional feature vectors, and combined with questionnaire data from 253 valid participants, this study developed a quantitative framework of plant visual features and adopted a two-level analytical approach. At the image level, linear mixed-effects models (LMMs) were used to identify how plant features influenced immediate responses. At the group level, partial least squares structural equation modelling (PLS-SEM) was employed to examine how cumulative restorative experience translated into affective states, perceived restorativeness, and behavioural intention. The results showed that Green View Index (GVI) and species richness were the most stable positive features, while plant health status, certain planting modes, and spatial layer-related features also showed significant effects. Restorative experience influenced behavioural intention mainly through positive affect and perceived restorativeness. These findings provide evidence for biophilic design, offering quantitative support for incorporating indoor public space into broader urban nature and public space framework. Full article