Search Results (2,218)

The formation, development, and spatial distribution of CUHIs are influenced by urban spatial heterogeneity, yet the scale and seasonal dependencies of the effects of urban morphology modulation on CUHIs have not been fully explored, needing further study. Based on multi-source data for the Yangtze-Huaihe River Valley (YHRV), this study employs the XGBoost model to systematically investigate the effects of two-dimensional (2D)/three-dimensional (3D) urban morphological indicators on CUHIs and their inherent scale–seasonal dependencies. Results show significant provincial heterogeneity in YHRV’s CUHIs: Shanghai exhibits the highest CUHI intensity (CUHII) across all seasons, with a peak of 1.55 °C in winter, followed by Zhejiang and Jiangsu. Seasonally, winter CUHII averages 0.6–0.8 °C (the highest), followed by autumn, while spring and summer have lower values. The effect of the modulation of urban morphology on CUHIs exhibits distinct spatiotemporal dependence: in winter and autumn, CUHII is mainly dominated by the percentage of landscape (PLAND) and largest patch index (LPI) at the 4 km buffer scale (correlation coefficients r = 0.475 and 0.406 for winter); in spring and summer, the 2 km buffer scale shows a more balanced regulatory role of multiple urban morphological indicators. Notably, 2D indicators of urban morphology are consistently more influential in regulating CUHIs than 3D indicators. The Hefei station case effectively validates the model’s sensitivity to changes in urban morphology. This study provides a quantitative basis for season–scale collaborative regulation of urban thermal environments in the YHRV. Future research will integrate climatic factors into XGBoost via screening, reconstruction, and interaction quantification to enhance its predictability for transient heat island processes. Full article

The Western Reef Heron (Egretta gularis) has a wide geographic distribution, ranging from the coasts of West Africa to Southwest Asia, including the Arabian Peninsula. Despite this extensive range, detailed information on its incubation behavior remains scarce. To address this gap, we investigated the 24 h incubation behavior of Western Reef Herons on Al-Fanateer Island, Eastern Saudi Arabia, during early summer—a period characterized by pronounced diurnal fluctuations in ambient temperature. Using trail cameras and temperature loggers, we found that adults maintained nearly continuous attendance at the nest throughout the day, with incubation coverage exceeding 97% across all two-hour intervals. A slight reduction in nest attendance was observed during nighttime (lowest at 86.8% between 20:00–21:59). Incubating adults exhibited behavioral plasticity in response to ambient temperature: a sitting posture was predominant during cooler periods, while a shading posture was more frequent during peak heat. Incubating adults also adjusted their orientation with the solar angle, actively avoiding southern and western exposures during the hottest parts of the day. Despite substantial variation in ambient temperature, the temperature beneath the clutch ranged from 29.4 to 37.8 °C, which may indicate effective thermoregulation. These findings suggest that a combination of near-continuous nest attendance, posture adjustment, and solar orientation avoidance allows Western Reef Herons to mitigate thermal stress and maintain optimal conditions for embryo and chick development. We recommend long-term monitoring of incubation behavior in this species to further evaluate its adaptability to environmental changes, particularly those driven by climate variability. Full article

In the context of ongoing global warming and urbanization, the need for reliable temperature monitoring in urban areas is increasing. Such monitoring serves multiple purposes, including assessing urban heat island (UHI) intensity, evaluating climate adaptation strategies, and supporting heat warning systems. This study utilizes high-resolution urban climate simulations with PALM-4U for calm, clear-sky summer weather conditions and an idealized model domain. The domain represents a dense midrise urban district in Dresden Neustadt, eastern Germany. Areas with air temperatures representative of the pedestrian level within the urban development are determined using a methodology based on a 24-hour temporal moving representativity range defined by the temperature’s spatial median value and standard deviation. The method is extended by an evaluation of different temperature sensor heights, addressing practical considerations such as vandalism prevention and space availability. The results highlight the feasibility of representative pedestrian-level air temperature monitoring in densely built-up urban areas, particularly at elevated sensor heights between 2.5 and 6.5 m. It is found that higher sensor heights increase the area suitable for representative pedestrian-level temperature monitoring by up to about 50%. The sensitivity of the results to variations in wind speed and building height is also examined, demonstrating the robustness of the proposed method in clear, calm summer weather conditions. Full article

Wind fields on tropical islands are among the most complex systems in atmospheric science, simultaneously influenced by large-scale monsoons, tropical cyclones, local sea-land circulation, and island topography. These interactions result in extremely complex responses to climate change, posing significant challenges for detailed assessment. This study examines how multi-scale processes have shaped the long-term evolution of the near-surface wind speed over Hainan, China’s largest tropical island. We developed a new high-resolution (5 km, hourly) regional climate reanalysis spanning 1961–2022, based on the WRF model and ERA5 data. Our analysis reveals three key findings: First, the long-term trend of wind speed over Hainan exhibits significant spatial heterogeneity, characterized by “coastal stilling and inland strengthening.” Wind speeds in coastal areas have decreased by −0.03 to −0.09 m/s per decade, while those in the mountainous interior have paradoxically increased by up to +0.06 m/s per decade. This pattern arises from the interaction between the weakening East Asian Winter Monsoon and the island’s complex terrain. Second, the frequency of extreme wind events has undergone seasonal reorganization: days with strong winds linked to the winter monsoon have significantly decreased (−0.214 days per decade), whereas days linked to warm-season tropical cyclones have increased (+0.097 days per decade), indicating asynchronous evolution of climate extremes. Third, the risk from 100-year extreme wind events is undergoing geographical redistribution, shifting from the coast to the mountainous interior (with an increase of 0.4–0.7 m/s in inland areas), posing a direct challenge to existing engineering design standards. Taken together, these findings demonstrate that local topography can significantly influence large-scale climate change signals, underscoring the critical role of high-resolution modeling in understanding the climate response of such complex systems. Full article

In response to the urban heat island challenge, various mitigation measures have been explored, with water spray systems emerging as a cost-effective and efficient solution for urban outdoor cooling. However, the influential factors of a water spray system on cooling efficiency have not been fully understood, thus hindering the application of the water spray system. This study delves into the following two questions: (1) what is the cooling performance of a water mist spray in a hot and humid urban climate? (2) What are the effects of different influencing factors? To answer these two questions, the computational fluid dynamics (CFD) simulations are used to modelthe cooling process of water mist spray inside an ideal two-dimensional street canyon with an aspect ratio of 1. A sound validation for the water spray cooling was conducted prior to the following CFD simulations. Results show that for given values of the water flow rate (i.e., 9.0 L/min) and the spray nozzle height (i.e., 3 m), a maximum temperature reduction of about 4.6 °C can be achieved at pedestrian height. Raising the installation height is more effective in maintaining the cooling zone proportion than decreasing the water flow rate. The clockwise recirculation inside the street canyon disappears with the upward airflow weakened when the spray nozzle is installed in the middle of the street canyon. Full article

Rapid urban growth leads to an extension of artificial surfaces and inefficient energy management, an increase in urban heat islands, and local climate change. This has increased the need for green infrastructure and urban trees are playing an important role. It is important to ensure that tree groups can withstand climate warming and disturbances. This study investigated the physiological parameters of Tilia tomentosa ‘Seleste’ trees situated in a medium-sized Hungarian city, examining their relationship with microclimatic differences observed on opposing sides of a street. Instruments placed on 10 trees recorded air temperature and humidity, revealing a significant difference in total insolation, which resulted in higher maximum daily temperatures on the sunny side. These microclimatic variations were found to significantly affect physiological attributes, particularly pigment content. Trees on the sunny side exhibited a higher relative water content and a higher ratio of chlorophyll a/b, indicative of light acclimatisation. Trees on the sunny side exhibited a higher relative water content and a higher ratio of chlorophyll a/b, indicating an acclimatisation to light. Furthermore, a positive correlation was observed between pigment content, total insolation, and growing degree days. The findings demonstrate how fine-scale microclimate differences influence tree physiology, providing crucial physiological indicators that inform the capacity of urban trees to provide vital ecosystem services, such as local climate regulation. This emphasises the importance of climate-conscious urban planning, as even small-scale climate change can have a broader impact. Full article

Peanut cultivation currently plays a minor role in Portuguese agriculture, despite the country’s favorable soil and climatic conditions. In the Azores archipelago, where agriculture is a key economic activity, peanut production has recently sparked interest among rural producers. Weeds pose a major threat to crop development, particularly for short-cycle species like peanuts. This study aimed to determine the period prior to weed interference (PPI) in peanut crops under two row spacings (40 cm and 60 cm) on São Miguel Island, Azores. Eight treatments were established—0–15, 0–30, 0–45, 0–60, 0–75, 0–90 days after emergence (DAE), full-season coexistence, and a weed-free control—to represent increasing periods of weed competition. A randomized block design with four replicates was used for each spacing. The weed community included eight species, with Cyperus spp., Digitaria spp., Amaranthus blitum, and Portulaca oleracea being the most prevalent. Weed interference throughout the entire cycle led to yield losses exceeding 81% and 86% at 40 cm and 60 cm row spacings, respectively. The PPI was defined at a 5% yield reduction threshold, which is a commonly accepted benchmark in weed science to determine the beginning of the critical period of weed interference. Full article

Islands and island communities are often perceived as homogenous in mainstream discourse. While many islands share characteristics, such as smallness or isolation, these are experienced differently across and within island contexts and intersect with spatial, socio-cultural, political, and economic landscapes. The concept of islandness is developed to both understand shared island characteristics and their differences across places, communities, and situations. This makes islandness highly relevant to discussions of green transitions as it highlights the need to examine the diverse, intersecting, and local realities that might interfere with green citizenship. However, analytical approaches to islandness are limited, with few spatial, scalable, and transferable frameworks available. This paper argues that spatial microsimulation offers a productive way to engage with islandness using the case of climate change and environmental attitudes across Iceland. We present the SimIceland model, developed within the EU-funded project PHOENIX: The Rise of Citizens’ Voices for a Greener Europe. The model is developed to better understand how Iceland’s citizens’ feel about climate change by taking socio-cultural, environmental, and different geographical administrative regions into account. Through a simple example of an analytical demonstration, we show how this model can support a deeper understanding of islandness in the specific context of climate attitudes in Iceland. Furthermore, we discuss how the model can contribute to public participation initiatives. The model and data are open access, and we conclude by inviting further developments and the use of spatial microsimulation to explore islandness, green citizenship, and participatory approaches to sustainability in island contexts. Full article

The negative consequences of climate change—such as heatwaves, storms, and floods—together with emerging threats including war, radiation, and pandemics, are increasingly affecting human health, ecosystems, economic stability, and the overall living environment. Consequently, enhancing preparedness has become a key task in shaping the spatial structure of cities. However, despite the growing negative impact and increasing frequency of climate change consequences, along with the prevailing risk of other threats, Lithuania is still not adequately prepared. The article examines the urban environment of Lithuanian cities and its local climatic assessment, aiming to develop proposals to enhance the sustainability and resilience of this environment in addressing the negative consequences of these threats. Three main climatic regions of the country were selected for the research, represented by cities: Klaipėda, Kaunas, and Vilnius. Urban and local climatic research was carried out in the selected cities to assess their spatial structure and environment and identify for microclimatic research the unified morphostructure types commonly used in the country. Accordingly, to selected morphotypes, correlations of the relationship between development density, building height, and the area of impervious surfaces with air and surface temperatures were carried. The most favourable microclimatic conditions were identified in morphotypes characterised by lower development density, more abundant green spaces, and a more open development pattern. Such characteristics of urban morphostructures, considering additional factors of land use such as land saving and the efficient functioning of the city, form the basis for developing the spatial structure of sustainable urban residential areas. Full article

Green roofs are effective passive strategies for enhancing building energy efficiency and indoor thermal comfort, particularly in response to climate change. This study presents an experimental and numerical assessment of an ultra-lightweight, soil-free green roof system for Mediterranean climates. In situ thermal monitoring was carried out on two identical test rooms in Rome (Italy), comparing the green roof to a traditional tiled roof under winter conditions. Results revealed a 45% reduction in thermal transmittance. These data were used to calibrate a dynamic TRNSYS 18 model and then applied to annual simulations of energy demand and indoor comfort across different roof configurations, including expanded polystyrene-insulated reference roofs. The model was calibrated in accordance with ASHRAE Guideline 14, achieving an MBE within ±10% and a CV(RMSE) within ±30% for hourly data, ensuring the simulation’s reliability. The green roof reduced cooling energy demand by up to 58.5% and heating demand by 11.6% relative to the uninsulated reference case. Compared to insulated roofs, it maintained similar winter performance while achieving summer operative temperature reductions up to 0.99 °C and PPD decreases up to 2.94%. By combining field measurements with calibrated simulations, this work provides evidence of the green roof’s effectiveness as a passive retrofit solution for Mediterranean buildings. Full article

The betel palm is a critical economic crop on Hainan Island. Accurate and timely maps of betel palms are fundamental for the industry’s management and ecological environment evaluation. To date, mapping the spatial distribution of betel palms across a large regional scale remains a significant challenge. In this study, we propose an integrated framework that combines knowledge-based and machine learning approaches to produce a map of betel palms at 10 m spatial resolution based on Sentinel-1/2 data and Google Earth Engine (GEE) for 2023 on Hainan Island, which accounts for 95% of betel nut acreage in China. The forest map was initially delineated based on signature information and the Green Normalized Difference Vegetation Index (GNDVI) acquired from Sentinel-1 and Sentinel-2 data, respectively. Subsequently, patches of betel palms were extracted from the forest map using a random forest classifier and feature selection method via logistic regression (LR). The resultant 10 m betel palm map achieved user’s, producer’s, and overall accuracy of 86.89%, 88.81%, and 97.51%, respectively. According to the betel palm map in 2023, the total planted area was 189,805 hectares (ha), exhibiting high consistency with statistical data (R² = 0.74). The spatial distribution was primarily concentrated in eastern Hainan, reflecting favorable climatic and topographic conditions. The results demonstrate the significant potential of Sentinel-1/2 data for identifying betel palms in complex tropical regions characterized by diverse land cover types, fragmented cultivated land, and frequent cloud and rain interference. This study provides a reference framework for mapping tropical crops, and the findings are crucial for tropical agricultural management and optimization. Full article

The increasing frequency of extreme weather events presents serious challenges to both regional and global economies. This study focuses on quantifying the economic losses caused by three major types of extreme climate events (heatwaves, droughts, and heavy rain) in Hainan Island from 2001 to 2020. Moreover, a comprehensive dataset of related economic losses was developed. To support the analysis, we constructed an Extreme Climate Economic Loss Model (ECELM). Drought and heavy rain losses were estimated using a loss intensity index based on precipitation and typhoon landfall wind speeds. Heatwave-related losses were assessed through a threshold-based optimization approach. The results show that both heatwaves and heavy rain have exhibited increasing impacts from 2001 to 2020. Although heatwaves were the most frequent extreme event in more than half of the years, heavy rain caused the highest cumulative losses, reaching CNY 75 billion. Spatial analysis indicates that the southeastern coastal areas were the most severely affected. These findings provide valuable quantitative evidence for designing targeted regional climate adaptation strategies. Full article

This study applies the Integrated Modification Methodology (IMM) to assess how morphology-driven, nature-based solutions reduce urban heat island (UHI) effects and flooding in Rio de Janeiro’s Cidade Nova. Multi-scale GIS diagnostics identify green continuity and vertical permeability as critical weaknesses. Simulations (Ladybug/Dragonfly) and hydrological modelling (rational method) quantify the intervention’s impact, including greening, material retrofits, and drainage upgrades. Results show a 38% increase in albedo, a 13% reduction in volumetric heat capacity, and a 30% drop in thermal conductivity. These changes reduce the peak UHI by 0.2 °C hourly, narrowing the urban–rural temperature gap to 3.5 °C (summer) and 4.3 °C (winter). Hydrologically, impervious cover decreases from 22% to 15%, permeable surfaces rise from 9% to 29%, and peak runoff volume drops by 27% (16,062 to 11,753 m³/h), mitigating flood risks. Green space expands from 7.8% to 21%, improving connectivity by 50% and improving park access. These findings demonstrate that IMM-guided interventions effectively enhance thermal and hydrological resilience in dense tropical cities, aligning with climate adaptation and the Sustainable Development Goals. Full article

Urbanization is a dominant force reshaping human settlements, driving socio-economic development while also causing significant environmental challenges. With over 56% of the world’s population now residing in urban areas—a figure expected to rise to two-thirds by 2050—land use changes are accelerating rapidly. The conversion of natural landscapes into impervious surfaces such as concrete and asphalt intensifies the Urban Heat Island (UHI) effect, raises urban temperatures, and strains local ecosystems. This study investigates land use and landscape changes in Ceredigion County, UK, utilizing remote sensing and GIS techniques to analyze urbanization impacts over two decades (2003–2023). Results indicate significant urban expansion of approximately 122 km², predominantly at the expense of agricultural and forested areas, leading to vegetation loss and changes in water availability. County-wide mean land surface temperature (LST) increased from 21.4 °C in 2003 to 23.65 °C in 2023, with urban areas recording higher values around 27.1 °C, reflecting a strong UHI effect. Spectral indices (NDVI, NDWI, NDBI, and NDBaI) reveal that urban sprawl adversely affects vegetation health, water resources, and land surfaces. The Urban Thermal Field Variance Index (UTFVI) further highlights areas experiencing thermal discomfort. Additionally, machine learning models, including Linear Regression and Random Forest, were employed to forecast future LST trends, projecting urban LST values to potentially reach approximately 27.4 °C by 2030. These findings underscore the urgent need for sustainable urban planning, reforestation, and climate adaptation strategies to mitigate the environmental impacts of rapid urban growth and ensure the resilience of both human and ecological systems. Full article

Urban areas face significant challenges from heat islands, stormwater, and air pollution, yet green roof adoption is hindered by feasibility and economic uncertainties. This study proposes an integrated framework to optimize green roof strategies for urban sustainability. We combine deep learning for rooftop suitability screening, comprehensive ecosystem service valuation, life-cycle cost–benefit analysis under varying policy scenarios, and ENVI-met microclimate simulations across Local Climate Zones (LCZ). Using Dalian’s core urban districts as a case study, our findings reveal that all three green roof types (extensive, semi-intensive, and intensive) are economically viable when policy incentives and ecological values are fully internalized. Under the ideal scenario, intensive roofs yielded the highest long-term returns with a payback period of 4 years, while semi-intensive roofs achieved the greatest cost-effectiveness (BCR = 4.57) and the shortest payback period of 3 years; extensive roofs also reached break-even within 4 years. In contrast, under the realistic market-only scenario, only intensive roofs approached break-even with an extended payback period of 23 years, whereas extensive and semi-intensive systems remained unprofitable. Cooling performance varies by LCZ and roof type, emphasizing the critical role of urban morphology. This transferable framework provides robust data-driven decision support for green infrastructure planning and targeted policymaking in high-density urban environments. Full article