Search Results (2,028)

Climate change and land-use intensification are speeding up the loss of ecosystem services that support human health, food security, and environmental stability. Vegetative interventions—such as urban forests in cities and cover crops in farming systems—are increasingly seen as nature-based solutions for climate adaptation. However, their benefits are often viewed separately. This review combines 20 years of research to explore how these strategies, together, improve provisioning, regulating, supporting, and cultural ecosystem services across various landscapes. Urban forests help reduce urban heat islands, improve air quality, manage stormwater, and offer cultural and health benefits. Cover crops increase soil fertility, regulate water, support nutrient cycling, and enhance crop yields, with potential for carbon sequestration and biofuel production. We identify opportunities and challenges, highlight barriers to adopting these strategies, and suggest integrated frameworks—including spatial decision-support tools, incentive programs, and education—to encourage broader use. By connecting urban and rural systems, this review underscores vegetation as a versatile tool for resilience, essential for reaching global sustainability goals. Full article

Cool roof and green roof have been acknowledged as effective heat mitigation strategies for fighting against the urban heat island (UHI). However, empirical data in hot–humid climate are still insufficient. Experimental conventional, cool and green roofs (three types) were established to comprehensively investigate the thermal performances in Hong Kong under typical summer conditions, as retrofitting strategies for an office building. The holistic vertical thermal behavior was investigated. The comparative cooling potentials were assessed. The results reveal a “vertical thermal sequence” in peak temperatures of each substrate layer for the conventional, cool and green roofs on a sunny day. However, local reversion in the thermal sequence may occur on a rainy day. Green roof-plot C (GR_C) demonstrates the highest thermal damping effect, followed by plot B (GR_B), A (GR_A) and the cool roof (CR) in summer. On a sunny day, the thermal dampening effectiveness of the substrates in the three green roofs is consistent: drainage > soil > water reservoir > root barrier. The holistic vertical thermal profiling was constructed in a high-rise office context in Hong Kong. The diurnal temperature profiles indicate all roof systems could effectively attenuate the temperature fluctuations. The daily maximum surface temperature reduction (SDMR) was introduced for cooling potential characterization of the cool roof and green roofs with multiple vegetation types. On a sunny day, the cool roof and green roofs all showed significant cooling potential. SDMR on the concrete tile of the best performing system was GR_C (26 °C), followed by GR_B (22.4 °C), GR_A (20.7 °C) and CR (13.3 °C), respectively. The SDMR on the ceiling ranked as GR_C, GR_B, GR_A and CR, with 2.9 °C, 2.4 °C, 2.1 °C and 2.1 °C, separately. On a rainy day, the cooling effect was still present but greatly diminished. A critical insight of a “warming effect at the ceiling” of the green roof was revealed. This research offers critical insights for unlocking rooftop cooling potential, endorsing cool roof and green roof as pivotal solutions for sustainable urban environments. Full article

The Phoenix Metropolitan Area (PMA) is situated in the Sonoran Desert of Central Arizona, USA. The PMA is a focus of ongoing climate change and urban heat island research. This paper addresses differences in the receipt of shortwave irradiance (global radiation) between the city and its surroundings. Several weather networks (e.g., AZ Met, an Arizona agricultural network) and air quality monitoring sites allow for the determination of shortwave irradiance between urban and rural locales, as well as a preliminary relation to seasonal patterns of suspended particulates. Particulate matter 10 μm and smaller (PM10) ranges from ca. 10 µg/m³ to 30 µg/m³ from winter to summer in rural areas, whereas in the metropolitan area, PM10 often exceeds 40 µg/m³ year-round. On average, urban transmissivity (T) of shortwave irradiance is lower than rural values by 1% in summer to over 5% in winter, like other urban studies evaluating effects on irradiance. Percentage differences between a site on a local mountain and the valley floor (about 400 m difference) range from 1% in summer to 5% in winter, in sync with seasonal mixing height changes and vertical mixing of particulates. Full article

Tree canopies in urban areas have many important ecosystem functions, and councils have targets to increase urban tree canopy area, which has proved challenging. Urban centres have large areas of impervious surfaces, and there is a perception that impervious surfaces are harmful for urban tree growth as water cannot penetrate the soil in which trees are growing. We investigated tree crown growth of young trees of eight common urban tree species in a suburb of Melbourne, Australia, that either grew in streets that were impacted by impervious surfaces or in parks. Four tree species had shown sensitivity to rainfall by lower crown growth in a low-rainfall suburb before, while the other four species had similar crown growth in high- and low-rainfall suburbs. We identified 40 trees per species and location (street vs. park) that were planted between 2009 and 2011 and measured their tree crown area in 2014 and again in 2018 using remote-sensed images. Trees that grew in streets that were impacted by impervious surfaces had larger crowns in 2014 than trees in parks, but both showed similar crown growth rates of 2.3 m² yr⁻¹ in the four-year period. Only one species (Eucalyptus sideroxylon A.Cunn ex Woolls) had a statistically significant greater relative crown growth rate in parks compared to streets. There was no statistically significant difference in the relative or absolute crown growth rates in tree species that have shown a previous sensitivity to rainfall compared to those that were insensitive to rainfall. Our data indicate that impervious surfaces had no detrimental impact on tree crown growth. It is possible that trees grown in streets have sufficient water resources and may benefit from the lack of competition for water, whereas trees in parks must compete for water resources with other plants. Full article

Urbanization and industrialization have led to the coexistence of winter haze and summer heat island in some cities in northern China, but the mitigation effect of ventilation corridors is lack of quantitative evaluation. This paper introduces circuit theory into urban climate research. Taking Shenyang as a case study, it comprehensively employs three-dimensional urban landscape pattern indices (including SVF, FAD, and Z0) to guide ventilation corridor construction, establishes an analytical framework for PM_2.5 and LST, and quantifies the environmental benefits of ventilation corridors. The results show that the corridor generated by circuit theory can make 65.14% of path PM lower than the average level of the city; Among the 7 exit paths of wind corridors, the surface temperature of 4 channels is lower than the average level of the city. FAD is positively correlated with Z0 (R² = 0.7) and negatively correlated with SVF (R² = 0.61). Meanwhile, the circuit theory model identifies eight pinch points along ventilation paths. CFD software is employed to simulate atmospheric environments for six typical building layouts to guide subsequent urban planning. Therefore, the reasonable layout of urban morphology indicators and the construction of reasonable ventilation corridors can effectively control the atmospheric particulate pollution and the heat island effect in summer. Full article

Urban heat islands pose intensifying threats to public health, equity, and urban livability as climate change amplifies temperature extremes. This systematic review synthesizes evidence from 33 primary studies (2021–2025) examining health impacts, mitigation strategies, and policy integration. The analysis focuses on interaction mechanisms, specifically how mitigation strategies differentially reduce health burdens across vulnerable populations, to advance systems-level understanding of urban heat dynamics. Following PRISMA guidelines, the review examined these mechanisms across three interconnected domains: health burdens, physical mitigation effectiveness, and post-pandemic policy synergies. Findings reveal profound inequities in heat exposure and associated health outcomes, with disadvantaged populations experiencing 26–45% higher heat-related mortality risk and 3–4 °C greater exposure than affluent communities, even after controlling for income. Physical mitigation strategies show measurable effectiveness, providing 1–6 °C cooling from green infrastructure and 2–22 °C from cool surfaces. Optimal interventions vary by socioeconomic context, with urban trees being more effective in disadvantaged areas, while cool roofs are better suited to affluent zones. COVID-19 natural experiments demonstrated 30–50% anthropogenic heat reductions, revealing strategic opportunities for integrating heat mitigation with 15-Minute City planning and work-from-home normalization. Effective implementation requires moving beyond isolated interventions toward spatially differentiated, equity-centered strategies aligned across planning, transportation, and governance domains. The post-pandemic period presents a critical window for embedding heat mitigation into broader urban transformation agendas. Full article

The thermal influence of Urban Heat Islands (UHIs) is not limited to periods of high temperature but persists throughout the year. The present study utilizes hourly data collected over a period of one year from a network of hygrothermal monitoring stations with a high density, which were deployed across the city of Cáceres (Spain). The network was designed in accordance with the World Meteorological Organization’s guidelines for urban measurements (employing radiation footprints and surface roughness) and ensures representation of each Local Climate Zone (LCZ), characterized by those factors (such as building typology and density, urban fabric, vegetation, and anthropogenic activity, among others) that influence potential solar radiation absorption. The magnitude of the heat island effect in this city has been determined to be approximately 7 °C in summer and winter at the first hours of the morning. In order to assess the energy impact of UHIs, Cooling and Heating Degree Days (CDD and HDD) were calculated for both summer and winter periods across the different LCZs. Following the implementation of rigorous quality control procedures and the utilization of gap-filling techniques, the analysis yielded discrepancies in energy demand of up to 10% between LCZs within the city. The significance of incorporating UHIs into the design of building envelopes and climate control systems is underscored by these findings, with the potential to enhance both energy efficiency and occupant thermal comfort. This methodology is particularly relevant for extrapolation to larger and denser urban environments, where the intensification of UHI effects exerts a direct impact on energy consumption and costs. The following essay will provide a comprehensive overview of the relevant literature on the subject. Full article

As a typical nature-based solution, urban parks play an important role in mitigating urban heat island effects. Although previous studies highlighted the complex impacts of landscape morphology on urban park cooling effects (PCE), the interactions and impact thresholds between specific features on PCE remain insufficiently explored across different scales. Here, taking 119 parks in Wuhan, China, as examples, the PCE and their responses to landscape morphology were quantified across three scales, including 47 small, 41 medium, and 31 large parks. Results showed that 79.8% of parks (95) exhibited obvious cooling effects. From small to large parks, the largest park cooling distance (LPCD), area (LPCA), and intensity (LPCI), as well as the accumulative park cooling gradient (APCG) and intensity (APCI), showed upward trends, while largest park cooling efficiency (LPCE) declined. Scale-dependent differences in landscape morphology impacting PCE were evident. In small and medium parks, LPCD and LPCA were mainly shaped by the surrounding environment, while LPCI and LPCE were primarily determined by internal morphology. In large parks, LPCA, APCI, and APCG were impacted by the surrounding environment, while LPCD and LPCI were dominated by internal morphology. Moreover, interactions between specific landscape morphology features significantly enhanced the model explanatory power and exhibited clear impact thresholds on PCE. Overall, this study enhances our understanding of cross-scale cooling mechanisms of urban parks and offers practical implications for heat-governance-oriented park planning. Full article

In Mediterranean cities, high solar radiation combined with limited shading and vegetation intensifies the urban heat island (UHI) phenomenon. As the road network often covers a large portion of the cities’ surfaces and is mostly constructed using asphalt pavements, it can significantly affect the urban microclimate, leading to low thermal comfort and increased energy consumption. Recycled and waste materials are increasingly used in the construction of pavements in accordance with the principle of sustainability for minimizing waste and energy to produce new materials based on a circular economy. The scope of this study is to evaluate the effect of recycled or waste materials used in road pavements on the urban microclimate. The surface and ambient temperature of urban pavements constructed with conventional asphalt and recycled/waste-based mixtures are assessed through simulation. Two study areas comprising large street junctions near metro stations in the city of Thessaloniki, in Greece, are examined under three scenarios: a conventional hot mix asphalt, an asphalt mixture containing steel slag, and a high-albedo mixture. The results of the research suggest that the use of steel slag could reduce the air temperature by 0.9 °C at 15:00, east European summer time (EEST), while the high-albedo scenario could reduce the ambient temperature by 1.6 °C at 16:00. The research results are useful for promoting the use of recycled materials, not only as a means of sustainably using resources but also for the improvement of thermal comfort in urban areas, the mitigation of the UHI effect, and the reduction of heat stress for human health. Full article

The island of Gran Canaria (Spain) has undergone a significant transformation in wildfire dynamics over the past two decades, characterized by a decline in wildfire frequency but a marked increase in the severity and spatial impact of extreme events, particularly within the wildland–urban interface (WUI). This study analyzes wildfire activity between 2000 and 2020 using official datasets and statistical trend analyses, incorporating robust severity indicators and measures of burned area concentration. Results show a statistically significant decreasing trend in the number of wildfires, while burned area is extremely concentrated in a small number of high-intensity events, with four large wildfires accounting for more than 97% of the total affected area. Climatic influences on wildfire activity were assessed through the analysis of long-term meteorological indicators, focusing on trends in extreme heat days and precipitation as proxies for thermal stress and fuel moisture availability. The results indicate a substantial modification of the background climatic framework under which wildfires develop, although no direct causal relationships are inferred. In parallel, territorial processes—such as rural abandonment, increased fuel continuity, and the expansion of dispersed housing beyond consolidated settlements—act as key amplifiers of wildfire risk. Overall, the findings highlight a transition from emergency-oriented fire suppression toward resilience-based wildfire management, emphasizing the need to integrate climate adaptation, territorial planning, and stricter land-use regulation in WUI areas. Full article

The paper examines the phenomenon of urban envelopes, a conceptual parallel to building envelopes, which is considered an emerging theme in studies of the built environment. The term ‘envelope’ refers to various physical and non-physical occurrences in the built environment that delimit, enclose, or demarcate spatial configurations. In the first part of the paper, six distinct types of urban envelopes are identified: physical, programmatic, technological, ecological, environmental, and representational. These are defined based on a systematic literature review to clarify their form, role, and meaning in the context of contemporary cities. All six urban envelope types are formalised using ontology-building methods in Protégé and visualised through WebVOWL, producing domain-agnostic RDF/OWL models that support semantic interoperability. The results provide a concise definition of urban envelopes, which are becoming increasingly relevant in their non-physical representations, such as spaces of control (surveillance of public urban spaces), dynamic environmental and ecological phenomena (pollution, heat islands, and more), temporal or dynamic definitions of space use, and many others in the context of contemporary smart city development. The analysis of possible alignment with existing smart city-related ontologies is presented. By providing the methodology for linking urbanistic principles with data-driven smart city frameworks, the paper provides a unified methodological foundation for incorporating such emerging spatial phenomena into formal urban models. Full article

The intensifying Urban Heat Island (UHI) effect exacerbates urban heat stress. While vegetation is a key mitigation strategy, the quantitative effects of its spatial configuration are not fully understood. This study employed ENVI-met simulations to systematically evaluate how three design parameters—tree spacing (8–18 m), canopy structure (single/multi-layer, sparse/dense), and horizontal layout (enclosed, semi-enclosed, linear)—regulate summer microclimate in urban parks. Results demonstrated that reduced spacing and denser canopies significantly enhanced cooling and humidification. The multi-layer dense canopy and an enclosed “mouth-shaped” layout yielded the optimal performance, achieving a maximum daytime air temperature reduction and a corresponding humidity increase. Furthermore, layout orientation was identified as a critical modulating factor. Spatial configuration exerted a stronger influence on microclimate outcomes than structural complexity itself. This study provides a predictive, evidence-based framework for optimizing urban green space design. The framework and the derived design principles are directly transferable to other cities in humid subtropical climates, offering generalizable strategies to enhance microclimate regulation and climate resilience globally. Full article

Urbanization and climate change have intensified the urban heat island (UHI) effect, increasing the demand for sustainable cooling solutions. Greenery, particularly in urban settings, has gained attention as a passive design strategy to enhance urban thermal comfort. This study systematically reviews peer-reviewed literature published in the last decade to assess the effectiveness of greenery in mitigating urban heat. Using a precise selection process, studies indexed in Web of Science (WOS), ScienceDirect, and Scopus were analyzed to identify key findings, methodologies, and gaps in existing research. The results highlight the impact of green facades, green walls, and urban greenery on surface and air temperature reduction, energy efficiency, and microclimate regulation. Furthermore, the study examines variations in performance based on climate zones, vegetation types, and urban configurations. Findings suggest that while greenery significantly improves urban thermal comfort, further research is needed to standardize assessment methods and optimize implementation strategies. This review contributes to the growing body of knowledge on nature-based solutions and provides insights for policymakers, urban designers, and researchers aiming to integrate greenery into sustainable urban planning. Full article

Urban heat islands (UHIs) have intensified in rapidly urbanizing regions like New York, exacerbating thermal discomfort, public health risks, and energy consumption. While previous research has highlighted various environmental and socioeconomic contributors, most existing studies lack interpretable, fine-scale models capable of quantifying the effects of specific drivers—limiting their utility for targeted planning. To address this challenge, we develop an interpretable machine learning framework using Random Forest and XGBOOST to predict land surface temperature across 1800+ census tracts in the New York metropolitan area, incorporating vegetation indices, water proximity, urban morphology, and socioeconomic factors. Both models performed strongly (mean R² ≈ 0.90), with vegetation coverage and water proximity emerging as the most influential cooling factors, while built form features played supporting roles. Socioeconomic vulnerability indicators showed weak correlations with temperature, suggesting a relatively equitable thermal landscape. Optimization simulations further revealed that increasing vegetation to a threshold level could lower average surface temperatures by up to 6.38 °C, with additional but smaller gains achievable through adjustments to water access and urban form. These findings provide evidence-based guidance for climate-adaptive urban design and green infrastructure planning. More broadly, the study illustrates the potential of explainable machine learning to support data-driven environmental interventions in complex urban systems. Full article

Against the global backdrop of urbanization and sustainable development, urban parks—key public spaces for carbon sequestration, heat island mitigation, and public health promotion—have made their service performance a critical metric for evaluating urban human settlement quality. However, traditional evaluations relying on static questionnaires and aggregate indicators often fail to capture the spatiotemporal dynamics of park usage and complex supply–demand relationships. To address this gap, this study developed a three-dimensional dynamic evaluation model (“Vitality Level, Demand Matching, Service Supply”) for 59 urban parks in Gongshu District, Hangzhou, integrating multi-source data (mobile phone signaling, POIs, park vectors, demographic statistics). The model includes nine indicators (e.g., Temporal Activity Difference, Vitality Stability Index) with weights determined via the entropy weight method. Empirical results show: (1) Gongshu’s park service performance presents a “core-periphery” spatial disparity, with high-performance parks concentrated in central areas (e.g., West Lake Culture Square) due to convenient transportation and diverse functions; (2) Performance levels vary significantly between weekdays and weekends, with higher stability on weekdays and more pronounced supply–demand mismatches on weekends; (3) Time-series cross-validation and Monte Carlo simulations confirmed the model’s robustness. This framework shifts park research from “static quantitative description” to “dynamic performance diagnosis,” providing a scientific basis for refined planning and efficient management of parks in high-density cities. Full article