Search Results (57)

Cities in climatic transition zones face coupled radiative and evaporative stresses, and their carbon emission mechanisms differ significantly from those in humid regions. Taking Xi’an, a typical megacity in the transition zone, as a case study, this research utilises a 500 m × 500 m grid to integrate multi-source data for carbon emission accounting. By applying spatial autocorrelation and the Multi-scale Geographically Weighted Regression (MGWR) model, this study examines the spatial heterogeneity of carbon emissions and the mechanisms through which urban planning influences them. The results indicate that carbon emissions in Xi’an exhibit a “core–periphery” agglomeration pattern, with commercial land use exhibiting the highest emission intensity. Carbon emissions and land surface temperature are spatially coupled, consistent with a hypothesised positive feedback loop of the “dry heat island” effect. Morphological factors exhibit spatial non-stationarity: floor area ratio is positively associated with emissions in the old city centre, whereas mutual shading among super-high-rise buildings in the High-Tech Zone coincides with a weaker effect. Building density shows a positive association only where ventilation is limited. Land use mix and blue–green spaces show non-linear negative associations with emissions, with higher marginal benefits in arid–hot environments. This study proposes carbon reduction strategies for the renewal of old urban areas, business cores, and new ecological districts, providing empirical evidence and decision-making references for low-carbon spatial planning in cities within the climatic transition zone. Full article

In hot, semi-arid zones, cities are experiencing longer and more intense warm spells. Although the literature offers strategies to mitigate this threat, studies verifying their feasibility are limited. In this study, we aim to ascertain the feasibility of reducing land surface temperature (LST) through greening. We combine LST analysis with a feasibility assessment of cooling measures and consider physical and ownership dimensions alongside environmental and social factors, with Ouagadougou (Burkina Faso) serving as a case study. The average LST during the hottest period (April–May) was calculated from ECOSTRESS and Landsat remotely sensed data, and multiple regression models were used to analyse the relationship between LST and land cover/land use across the city’s districts and sectors. Our assessment incorporates greening scenarios, SWOT analyses, and equity assessments, and our results indicate that barren land is the primary determinant of diurnal LST. Planting 0.45 million trees could reduce LST by up to 2.4 °C in peripheral sectors if large roads, utilities, and vacant lands are targeted. This may reduce disparities in tree cover between sectors but could widen the gap between districts. Recommendations include a more hierarchical street network, enhancing utility provision, and reducing barren land in the peripheral sectors. Full article

Rapid population growth is increasing housing demand and accelerating the expansion of the built environment in Egypt. However, practical and sustainable residential building decarbonization remains constrained by limited supplies of supplementary cementitious materials, limited structural timber resources, code restrictions on cement reduction, and cost sensitivity. This study evaluates two Egyptian multi-unit residential case studies—one affordable housing project and one middle-class housing project—to assess whether wall-system substitution can reduce both embodied and operational carbon under local material, code, and cost constraints. An integrated BIM-based digital twin workflow was used to link quantity takeoff, finite-element structural assessment, and whole-building energy simulation. An architectural BIM model was used for material quantification, wall-system definition, and energy-model inputs. A structural model was used to assess the effects of reducing wall density on reinforcement and concrete demand under gravity and seismic load combinations. Operational performance was assessed through cooling-focused energy simulations under hot-arid climatic conditions representative of Egypt’s new desert cities. Alternative wall systems were then evaluated through scenario- based material substitution and revised structural and energy assessments. The results show that reinforcement, concrete, and wall- core materials account for about 80% of total embodied carbon, while cooling accounts for about 72% of operational emissions. Non-structural cement uses, mainly mortars and finishes, account for 36% of total cement demand, ranging from 161 to 229 tons per building across the two case studies. Replacing conventional partition walls with lightweight, energy-efficient alternatives reduced embodied carbon by up to 35.2%, operational carbon by about 15.7% to 16.5%, and total life-cycle carbon by about 17.4% to 17.5% over a 60- year service life. The average savings per building corresponded to avoiding about 30 tons of steel, 165 m³ of ready-mix concrete, and 191 m³ of mortar, with net cost savings of about 3.15 million EGP per building. These results identify a practical pathway toward more sustainable, lower-carbon Egyptian residential buildings without increasing project cost. Full article

Urban heat stress is a growing challenge in hot semi-arid cities, where neighbourhood urban design influences microclimate and outdoor comfort. This study evaluates the effect of neighbourhood spatial layout in Erbil city, using ENVI-met simulations. Five neighbourhoods with varying layouts were modelled under standardized conditions, including uniform building height, surface characteristics, and meteorological forcing. Hourly outputs of air temperature, relative humidity, wind speed, surface temperature, mean radiant temperature, universal thermal climate index, and sky view factor were analyzed after excluding the spin-up period. Results indicate that, while all neighbourhoods exhibited similar diurnal timing of thermal extremes, a key distinctive finding is the identification of a neighbourhood that behaves differently across seasons. The Pavilion neighbourhood remained cooler during summer conditions, while maintaining warmer thermal conditions during winter. This dual seasonal behaviour contrasts with the other neighbourhoods, which generally exhibit a trade-off between reduced summer heat stress and winter cooling. The Pavilion neighbourhood is distinguished by the presence of integrated water lagoons, suggesting that the blue infrastructure, in combination with spatial openness and greenery, can moderate thermal extremes. Overall, the study highlights the importance of neighbourhood-scale spatial design in mitigating urban heat and provides evidence to support the development of sustainable neighbourhoods. 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

The rising demand for cooling in hot semi-arid cities like Jaipur is putting increasing pressure on energy infrastructure and urban resilience. This study investigates the potential of Jaali, a traditional perforated screen used in Indian architecture, as a passive strategy to reduce energy demand in a contemporary office building through data-driven optimisation and computational analysis. Using detailed energy simulations in DesignBuilder, this research explores how variations in orientation, cavity depth, perforation ratio and screen thickness affect cooling performance during the summer months through a systematic parametric study generating 84 simulation configurations. The model is based on a 12-storey office building designed according to local energy codes. The results show that the optimal configuration differs by orientation. On the south façade, the optimal combination is a 100 mm Jaali with 20% perforation and a 1.5 m cavity, which delivers the best performance. The west façade performs best with a thicker 150 mm screen, the same 20% perforation ratio, and a 1.0 m cavity depth. On the east façade, the strongest performance is achieved with a 150 mm Jaali, 50% perforation, and a 1.5 m cavity, with cooling demand reduction of up to 8.71%. These findings demonstrate that traditional design elements, when optimised for modern use, can offer measurable energy savings through predictive modelling frameworks. More importantly, their widespread adoption could support urban cooling strategies, reduce peak electricity loads and contribute to sustainable development across rapidly growing cities in hot climates. The comprehensive dataset generated provides a foundation for future AI-enhanced building energy optimisation applications. Full article

The Dammam Metropolitan Area (DMA) has been experiencing tremendous growth driven by increasing population and the oil industry. This has culminated in the development of the DMA, where the transportation system is reliant on automobiles, wide arterials, and a disjointed pedestrian environment. With the increasing progression of the Vision 2030 initiative, the Kingdom of Saudi Arabia (KSA) is focusing on livability and sustainable mobility. However, despite the massive efforts, the concepts of humanizing active mobility corridors remain insufficiently developed across Saudi cities. The paper will discuss the conceptual framework for developing the active mobility corridors of the DMA, an initiative of walkability, livability, and sustainable mobility with specific regard to the study region’s climatic and cultural environment. The methodology relies on qualitative desktop research supported by a structured and iterative literature synthesis using snowballing techniques. The resulting framework positions active mobility not merely as a transport function, but as a multidimensional system that promotes inclusion, comfort, and environmental resilience. Offering design and policy principles tailored to hot-arid Gulf contexts that contributes to national efforts to advance Quality of Life objectives under Vision 2030. Ultimately, this framework aims to contribute in human-centered mobility across the KSA and similar urban areas. Full article

Urban vegetation is widely promoted as a nature-based solution for mitigating outdoor thermal stress in hot-arid cities, but aggregated or static indicators obscure species-specific behavior, diurnal variability, and the linkage between outdoor comfort and building energy demand in courtyard environments. This study addresses these constraints by integrating outdoor thermal comfort mitigation and cooling energy performance using a reference-based, species-sensitive analytical methodology. The Vegetation Cooling Efficiency Index (VCEI) quantifies vegetation-induced reductions in Physiologically Equivalent Temperature (PET) relative to a non-vegetated reference scenario and is normalized by vegetation coverage. The PET–Energy Sensitivity Index (PESI) characterizes building cooling energy demand’s responsiveness to outdoor thermal comfort. A hybrid approach integrating calibrated field measurements, hourly microclimatic simulations, and dynamic building energy modeling is applied to a university courtyard in Aswan City, Egypt, reflecting extreme hot-arid conditions. The canopy features of Cassia leptophylla (CL), Cassia nodosa (CN), and Ficus nitida (FN) are assessed across varied vegetation coverage ratios. The results show that vegetation covering alone cannot predict thermal mitigation outcomes. PET reduction is influenced by species-specific canopy structure, with peak-hour reductions surpassing 40 °C in dense-canopy species and significantly lower ΔPET values across vegetation coverage levels. The nonlinear relationship between outdoor thermal mitigation and indoor cooling energy demand underscores the necessity for a comprehensive comfort-energy assessment. The proposed indices allow for comprehensive, reference-based vegetation strategy comparison and transferable performance measurements for climate-responsive courtyard and campus design in hot-arid environments. Full article

Contaminated environmental surfaces (fomites) act as pathogen reservoirs, yet surveillance data in arid megacities like Riyadh, Saudi Arabia—characterized by extreme heat and indoor climate control—remain limited. This study established a city-wide molecular baseline for surface contamination and evaluated meteorological influences. We conducted a stratified, longitudinal study (February 2023–May 2024), collecting 270 swabs from seven zones, including hospitals, airports, ATMs, and community hubs. Samples were pooled (N = 55) and screened using QIAstat-Dx multiplex PCR panels. Nineteen pools (34.5%) tested positive. Viral pathogens (SARS-CoV-2, Adenovirus, Rhinovirus) were detected in 10 pools (18.2%) and non-viral pathogens (bacteria/parasites) in 13 pools (23.6%), with 7.3% co-detections. Hospitals and airports emerged as primary hubs for respiratory viruses, while Cryptosporidium was the most frequent non-viral pathogen (n = 6), predominating on ATM interfaces. Binary logistic regression indicated that higher ambient temperature was significantly associated with detecting viral rather than non-viral pathogens among positive samples (OR = 1.728, p = 0.032). Despite outdoor aridity, public surfaces in Riyadh harbored diverse pathogens. The link between heat and viral detection suggests indoor microclimates drive persistence during hot seasons, necessitating targeted hygiene measures in high-risk nodes. Full article

Egypt generally experiences a hot and arid climate, with rainfall primarily confined to the northern coast during winter season. However, on 31 May 2025, Alexandria experienced an unusual late-spring convective storm that was associated with heavy rainfall, strong winds, intense lightning, and localized hail. This rare event caused temporary disruptions to urban life and underscored the growing vulnerability of coastal cities to short-duration, high-intensity precipitation events occurring outside the climatological rainy season. This study investigates the atmospheric mechanisms underlying this event through a comprehensive synoptic and dynamic analysis of pressure systems, wind fields, and temperature structures extending from the surface to the 200 hPa level. Particular emphasis is placed on the role of moisture convergence and upper-level dynamical forcing in triggering the rapid development of deep convection. Furthermore, the influence of anomalous large-scale circulation patterns on storm initiation and intensification is systematically examined. Improved understanding of these processes provides valuable insight into off-season convective activity over the southeastern Mediterranean and enhances forecasting capability, risk assessment, and early warning strategies for similar extreme events in the region. Furthermore, the influence of anomalous large-scale circulation patterns on storm initiation and intensification is quantitatively assessed to clarify their contribution to the event’s development. A deeper understanding of these processes offers critical insight into the mechanisms governing off-season convective activity over the southeastern Mediterranean and strengthens forecasting skill, risk assessment frameworks, and early warning systems for comparable extreme events in the region. Full article

Contemporary urbanisation in hot-arid cities presents coupled challenges related to sustainability, spatial efficiency, and climate resilience. This study applies Research by Design as a preliminary methodological approach to adapt the superblock typology for Riyadh’s Al-Raed neighbourhood, integrating GIS-based territorial diagnosis with Grasshopper parametric iterations. Sixteen geospatial layers, including land use, density, road hierarchy, transit access, service distribution, green cover, and climatic exposure, inform attractor-based scenario generation and a structured comparative evaluation framework assessing regulatory compliance, human scale, connectivity, and environmental and economic feasibility. The resulting loop-and-courtyard configuration reorganises local streets to strengthen first- and last-mile access, shaded pedestrian continuity, and microclimatic comfort, while supporting Saudi Vision 2030 programs, such as the Quality of Life Program, National Transport and Logistics Strategy, Riyadh Public Transport Program, and Saudi Green Initiative. Quantitative spatial indicators are interpreted alongside design-based morphological reasoning to inform spatial decisions, acknowledging climatic and cultural constraints. This study contributes a reproducible, policy-relevant digital workflow for neighborhood-scale urban transformation in Riyadh and comparable hot-arid contexts. As a preliminary Research by Design phase, it structures iterative scenarios and a structured comparative evaluation framework, providing a foundation for subsequent quantitative and empirical validation. Full article

Saudi Arabia’s ambition to improve quality of life is paving its way, and this study aligns with that vision, adopting an experimental approach to explore urban solutions to enhance outdoor thermal comfort for pedestrians in neighborhoods within Riyadh City, Saudi Arabia. Given the city’s hot and arid climate, outdoor spaces are often subject to extreme thermal conditions that reduce the quality of life for residents. To address this issue, the study utilizes Ladybug in Grasshopper, a tool designed for modeling the microclimate and assessing the impact of urban design strategies on outdoor thermal comfort. A base model representing the current urban fabric of selected neighborhoods is developed, and then multiple alternatives of urban morphology (sidewalk, setbacks, fence, and vegetation) are evaluated for their effectiveness in mitigating heat stress and improving outdoor thermal conditions. The findings from this study provide valuable insights into how urban planning and design interventions can be tailored to the unique climatic challenges of Riyadh, with potential applications for enhancing the sustainability, livability, and overall quality of life of the city’s neighborhoods. Full article

Inner courtyards have been traditionally used as passive strategy in vernacular buildings in desert climates. This paper presents a study conducted to investigate indoor and outdoor thermal comfort of two vernacular buildings in the hot arid climate of Upper Egypt and proposes an improved solution for courtyards to achieve sustainable development of current vernacular houses and apply the same in the arid climate zone of Egypt. The thermal comfort of vernacular building spaces was evaluated based on using field measurements during the hot season and improvement for courtyards based on ENVI-met V5.6.1 simulation model using three scenarios. Two vernacular buildings (Hassan Fathy and Nubian house) were selected to represent the traditional buildings south of Egypt. The study found that using adobe bricks with high thermal mass in vernacular buildings maintained lower indoor temperature with a range of 2.7 °C to 6.7 °C compared to outdoor temperature; this is considered effective thermal insulation. Meanwhile under extreme hot conditions, courtyard temperature inside the vernacular house was 0.3 K higher than the outdoor. This is not sufficient to maintain indoor thermal comfort without integrating passive solutions inside courtyards. In addition, applying the hybrid solution with big dense trees in the courtyards achieved a significant reduction in PET ranging from 4.2 °C and 5.7 °C; shading the widest area of courtyards and allowing for family activities. The study provided techniques and methodology for the middle courtyard of vernacular buildings, demonstrating how improvement achieves thermal comfort and sustainable development required in the 21st century in Upper Egypt, and can be applied to other vernacular houses in different desert cities in southern Egypt. Full article

Amid long-term human consumption of surface resources and the intensifying climate crisis, underground space has increasingly attracted attention as a viable alternative for habitation, survival, and urban resilience. Historical and contemporary examples—from the Derinkuyu Underground City in Cappadocia, Turkey, to Iran’s “Shavadan” cooling system, as well as subterranean dwellings in hot arid regions such as the Berbers’ homes in Tunisia and miners’ settlements in Coober Pedy, Australia, and underground complexes in cold regions like Harbin, Sapporo, and Helsinki—demonstrate the significant advantages of underground spaces in thermal regulation, protection from extreme weather, and efficient resource utilization. With climate change driving increasingly frequent and severe extreme weather events, including tornadoes, typhoons, and prolonged droughts, surface buildings face growing vulnerability, further emphasizing the potential of underground space for sustainable urban development. In parallel, advances in science and technology, particularly in space exploration, have accumulated extensive practical knowledge, creating pathways to extend terrestrial construction experience into extraterrestrial environments. The Moon, despite its strategic significance and potential resource value, presents an extremely hostile surface environment characterized by microgravity, near-vacuum conditions, extreme diurnal temperature variations of several hundred degrees, and very low thermal conductivity, all of which render conventional surface habitation challenging and prohibitively costly. Consequently, contemporary research has gradually shifted focus from lunar surface facilities toward the development and utilization of lunar underground spaces, which could provide enhanced environmental stability and habitation potential. This paper reviews the historical development and current research on lunar underground space utilization, proposes five guiding principles for its progressive exploration and construction, and presents a phased “1.0–4.0 era” framework for systematic development. Additionally, based on an adaptive design theoretical framework, spatial, environmental, and climatic strategies are proposed to guide future lunar habitation and ensure sustainable extraterrestrial development, providing a comprehensive reference for long-term planning and construction of lunar underground habitats. Full article

The Surface Cool Island (SCI) refers to localized reductions in land surface temperature (LST) produced by features that enhance evapotranspiration, shading, and energy flux regulation. In arid urban areas, vegetated parks play a key role in mitigating heat through these mechanisms. This study evaluates how park vegetation structure and spatial configuration influence SCI intensity (ΔTmax) and extent (Lmax) using multi-seasonal, day–night satellite observations in Mexicali, Mexico. A total of 435 parks were analyzed using Landsat 8/9 TIRS (30 m) for LST and Sentinel-2 MSI (10 m) for vegetation mapping via NDVI thresholding and supervised random forest (RF) classification. On average, parks lowered daytime LST by 0.81 °C (max: 6.41 °C), with a mean Lmax of 120 m; nighttime cooling was weaker (avg. ΔTmax: 0.37 °C; Lmax: 48 m). RF-derived metrics explained SCI variability more effectively (R² up to 0.64 for ΔTmax; 0.48 for Lmax) than NDVI-based metrics (R² < 0.35), highlighting the value of object-based land cover classification in capturing vegetation structure. This remote sensing framework offers a scalable method for assessing urban cooling performance and supports climate-adaptive green space design in hot-arid cities. Full article