Search Results (110)

Urban surface temperatures are increasing because of climate change and rapid urbanisation, contributing to the urban heat island (UHI) effect and significantly influencing local climates. Satellite-derived land surface temperature (LST) plays a vital role in analysing urban thermal patterns. However, current satellite thermal infrared (TIR) sensors have a low spatial resolution, making it difficult to accurately capture the complex thermal variations within urban areas. This limitation affects the assessments of UHI effects and hinders effective mitigation strategies. We proposed a hybrid model named “geospatial machine learning” (GeoML) to address these challenges, combining random forest and kriging downscaling techniques. This method utilises high spatial resolution data from Sentinel-2 to enhance the LST derived from Landsat 8/9 data. Tested in Perth, Australia, GeoML generated an enhanced LST with good agreement with ground-based measurements, with a Pearson’s correlation coefficient of 0.85, a root mean square error (RMSE) of 2.7 °C, and a mean absolute error (MAE) of less than 2.2 °C. Validation with LST derived from another TIR sensor also provided promising outputs. The results were compared with the high-resolution urban thermal sharpener (HUTS) downscaling methods, which GeoML outperformed, demonstrating its effectiveness as a valuable tool for urban thermal studies involving high-resolution LST data. Full article

Ground-source heat pumps (GSHPs), despite their high efficiencies, are still not as cost-effective as air-source heat pumps, especially in urban environments, due to the necessity of drilling/excavation. Integrating GSHPs into existing geo-structures, such as underground tunnels, can play a vital role in reducing the overall costs of GSHP systems and promoting their use in cities. Tunnels can be realized through artificial ground freezing (AGF) by using probes for circulating the freezing fluid, which are left in the ground once the tunnel is completed. The novelty of the present work lies in the proposal of a sustainable reuse of AGF probes as ground heat exchangers (GHEs). The idea of converting AGF probes is both sustainable and cost-effective for GSHPs, as it can reduce installation costs by eliminating the drilling/excavation process. A test was performed for the first time in the Piazza Municipio metro station in Naples, Southern Italy, where several AGF probes, initially used for the construction of two tunnels, have then been converted into GHEs. The probes have been connected to a testing device called the energy box. The experiments included testing the heat transfer in the recovered AGF probes through cooling and heating operations. This work presents a numerical simulation of a test that has been validated against experimental results. Full article

The Mongolian Plateau, a critical area for global climate change response, faces increasing vulnerability from climate change and human activities impacting its arid ecosystems. This study integrates GeoDetector and machine learning to predict vegetation Carbon Use Efficiency (CUE) dynamics. It utilizes multi-source remote sensing data (MODIS, ERA5-Land) from 2000 to 2020 and incorporates four Shared Socioeconomic Pathways (SSPs) from CMIP6. The results indicate the following: (1) significant spatial variation exists, with high-value CUE areas (≥0.7) in the northwest due to favorable climatic conditions, while low-value areas (<0.6) in the east are affected by decreasing precipitation and overgrazing; (2) CUE increased at an annual rate of 1.03%, with a 43% acceleration after the 2005 climate shift, highlighting the synergistic effects of ecological engineering; (3) our findings reveal that the interaction of evapotranspiration and temperature dominates CUE spatial differentiation, with the random forest model accurately predicting CUE dynamics (root mean square error (RMSE) = 0.0819); (4) scenario simulations show the SSP3-7.0 pathway will peak CUE at 0.6103 by 2050, while the SSP5-8.5 scenario will significantly reduce spatial heterogeneity. The study recommends enhancing water–heat regulation in the northwest and implementing vegetation restoration strategies in the east, alongside establishing a CUE warning system. This research offers valuable insights for improving carbon sequestration and climate resilience in arid ecosystems, with significant implications for carbon management under high-emission scenarios. Full article

In Europe and elsewhere in the world, current ambitious decarbonization targets push towards a gradual decommissioning of all fossil-fuel-based dispatchable electrical generation and, at the same time, foster a gradual increase in the penetration of Renewable Energy Sources (RES). Moreover, considerations tied to decarbonization as well as to the security of supply, following recent geo-political events, call for a gradual replacement of gas appliances with electricity-based ones. As RES generation is characterized by a variable generation pattern and as the electric carrier is characterized by scarce intrinsic flexibility, and since storage capabilities through electrochemical batteries, as well as demand-side flexibility contributions, remain rather limited, it is quite natural to think of other energy carriers as possible service providers for the electricity system. Gas and heat networks and, in the future, hydrogen networks could provide storage services for the electricity system. This could allow increasing the amount of RES penetration to be managed safely by the electric system without incurring blackouts and avoiding non-economically motivated grid reinforcements to prevent the curtailment of RES generation peaks. What is explained above calls for a new approach, both in electricity network dispatch simulations and in grid-planning studies, which extends the simulation domain to other carriers (i.e., gas, heat, hydrogen) so that a global optimal solution is found. This simulation branch, called multi-energy or multi-carrier, has been gaining momentum in recent years. The present paper aims at describing the most important approaches to static ME modeling by comparing the pros and cons of all of them with a holistic approach. The style of this paper is that of a tutorial aimed at providing some guidance and a few bibliographic references to those who are interested in approaching this theme in the next years. Full article

The decrease in grain plantation areas poses a growing concern for global food security. China, with its large population, increasingly diversified food demands, and relatively small cultivated lands, has suffered deeply from this phenomenon (non-grain production, NGP) in recent years. Since 2020, the central government of China has claimed to deal with this problem by attracting agriculturalists and organizations involved in grain plantation. In this context, understanding the global NGP of the national situation is vital for policy making. Remote sensing is regarded as the most effective and accurate method for this purpose, but existing studies have mainly focused on algorithms operating at the local scale or exploring grain-producing capability from the perspective of agricultural space. As such, the characterization of NGP on a national scale remains deficient. In this study, we tried to bridge the gap through spatio-analysis with a newly published nationwide crop pattern and land use geo-datasets; the quantitative, spatial, and structural features, as well as the utilization of NGP cropland in the year 2019, were observed. The results showed that about 60% of the cropland was used for non-grain plantation. About 15% of the NGP parcels were cultivated with grains at least three times in the past 4 years, and of these 60% and 40% were parcels with double- or single-season plantation, respectively, which could result in a 16–22% increase in the grain-sown area compared with 2019. Forest and grassland were the dominant non-cropping categories which NGP cropland transferred into, indicating more time and economic cost for regaining grains. NGP parcels also presented spatio-heterogeneity regarding cropping intensity and transformation. Parcels with double-season plantation mostly emerged in northern, central, and southern provinces, while those with single-season plantation were always located in northeastern and western provinces. The parcels that were transferred into forest or grassland mainly appeared in southern and Inner Mongolia, respectively, while the parcels in northern and central areas mostly continued cropping. According to these results, we propose remediation policies focusing on raising the cropping intensity of cultivated land in central and northern provinces due to their advantages of water, heat, terrain, and land use change features. Future work is warranted based on this study’s deficiencies and uncertainties. As a forerunner, this study provides a holistic observation of the NGP phenomenon in mainland China on a national scale, and the findings can inform improvements in land use policies concerning grain production and food security in China. Full article

This article focuses on modern methods of documentation and visualization for a historic object. Digital photogrammetry and terrestrial laser scanning (TLS), which are essential tools for documenting cultural heritage in view of their rapid development in recent years, were used, compared, and analyzed. Furthermore, the use of available 3D computer graphics technologies for visualization is described and an optimal procedure for converting the object into VR and AR is proposed and implemented. The technologies presented in this article were tested within the context of a project on the reconstruction of the shrine of the Prophet Nahum in the city of Alqosh in northern Iraq, taking the shrine as a case study. Funded by ARCH Int. and provided by GemaArt Int., the restoration project started in 2018 and was completed in 2021. The ongoing documentation was prepared by the CTU and it used the materials for research purposes. Accurate documentation using photogrammetry, drones, and TLS was key to the restoration. Leica BLK360, Faro Focus S150, and GeoSlam laser scanners were used, as well as photogrammetric methods. In particular, the documentation process involved the creation of 3D textured models from the photogrammetry, which were compared to the TLS data to ensure accuracy. These models were necessary to track changes during the reconstruction phases and to calculate the volumes of rubble removed and materials added. Our data analysis revealed significant differences between the construction logs and the analysis of the accurate 3D models; the results showed an underestimation of the displaced material statements by 13.4% for removed material and 4.6% for added material. The use of heat maps and volumetric analyses helped to identify areas of significant change that guided the reconstruction and documented significant changes to the building for the investor. These findings are important for use in the construction industry with respect to historic sites as well as for further research focused on visualization using VR (virtual reality) and AR (augmented reality). The conversion of existing 3D models into VR and AR is rapidly evolving and significant progress was made during this project. The Unreal Engine (UE) game engine was used. Despite the significantly improved performance of the new UE 5 version, the data for conversion to VR and AR needs to be decimated to reduce the amount—in our case, this was by up to 90%. The quality appearance of the objects is then ensured by textures. An important outcome of this part of the research was the debugged workflow developed to optimize the 3D models for VR, which was essential for creating a virtual museum that shows the restoration process. Full article

Urban expansion encroaches on green spaces and weakens ecosystem services, potentially leading to a trade-off between ecological conditions and socio-economic growth. Effectively coordinating the two elements is essential for achieving sustainable development goals at the urban scale. However, few studies have measured urban–ecological linkage in terms of trade-off. In this study, we propose a framework by linking the degraded ecological conditions and urban land use efficiency from a return on investment perspective. Taking a rapidly expanding city as a case study, we comprehensively quantified urban–ecological conditions in four aspects: urban heat island, flood regulating service, habitat quality, and carbon sequestration. These conditions were assessed on 1 km² grids, along with urban land use efficiency at the same spatial scale. We employed the slack-based measure model to evaluate trade-off efficiency and applied the geo-detector method to identify its driving factors. Our findings reveal that while urban–ecological conditions in Zhengzhou’s periphery degraded over the past two decades, the inner city showed improvement in urban heat island and carbon sequestration. Trade-off efficiency exhibited an overall upward trend during 2000–2020, despite initial declines in some inner city areas. Interaction detection demonstrates significant synergistic effects between pairs of drivers, such as the Normalized Difference Vegetation Index and building height, and the number of patches of green spaces and the patch cohesion index of built-up land, with q-values of 0.298 and 0.137, respectively. In light of the spatiotemporal trend of trade-off efficiency and its drivers, we propose adaptive management strategies. The framework could serve as guidance to assist decision-makers and urban planners in monitoring urban–ecological conditions in the context of urban expansion. Full article

The deformation characteristics of soil after thermal desorption are crucial for the evaluation of engineering properties, but the evolution mechanism is currently unclear. This study focuses on the thermal desorption of contaminated soil, conducting Geo-dynamic Systems consolidation-rebound tests to reveal the evolution mechanism of consolidation–rebound deformation and pore pressure characteristics, and exploring the evolution mechanism through pore structure, particle size distribution, and Cation Exchange Capacity tests. Results show that the consolidation characteristics of uncontaminated soil increase and then decrease with heating temperature, with 400 °C as a turning point. In contrast, the consolidation deformation of contaminated soil continues to decrease. The vertical deformation of the soil in the pre/early consolidation stage is greater before 400 °C, while after 400 °C, the deformation continues to increase with consolidation pressure, and higher heating temperatures enhance the soil’s rebound deformation ability. Pore water pressure changes in two stages, with temperature ranges of 100–300 °C and 300–600 °C, and with increasing heating temperature, the characteristics of pore pressure change from clay to sand. Mechanism tests reveal that inter-aggregate pores affect initial deformation, while intra-aggregate pores affect later deformation, both showing a positive correlation. Aggregate decomposition increases initial deformation capacity at 100–400 °C while melting body fragmentation increases later deformation capacity at 500–600 °C. CEC decreases with increasing heating temperature, reducing inter-particle resistance and increasing soil deformation capacity. Particle size distribution and Cation Exchange Capacity impact consolidation–rebound pore pressure. Full article

The importance of mitigating energy intensity in the building sector is widely recognized by most stakeholders, and different strategies are proposed for minimizing fossil fuel dependency. This paper presents a complex study assessing the possibility of integrating an air-source heat pump (ASHP) into the retrofitting process of a typical Romanian residential building. Mathematical simulations were conducted to estimate the energy reduction potential of a complex renewable-energy-based HVAC system. The results showed that a more than 50% increase in energy efficiency could be obtained by using the right insulation materials, and the building’s fossil fuel dependency could be curbed by 75% by integrating the proposed renewable energy systems. Full article

In the context of sustainable urban development, elucidating urban heat island (UHI) dynamics in arid regions is crucial. By thoroughly examining the characteristics of UHI variations and potential driving factors, cities can implement effective strategies to reduce their impacts on the environment and public health. However, the driving factors of a UHI in arid regions remain unclear. This study analyzed seasonal and diurnal variations in a surface UHI (SUHI) and the potential driving factors using Pearson’s correlation analysis and an Optimal Parameters-Based Geographic Detector (OPGD) model in 22 cities in Xinjiang, northwest China. The findings reveal that the average annual surface urban heat island intensity (SUHII) values in Xinjiang’s cities were 1.37 ± 0.86 °C, with the SUHII being most pronounced in summer (2.44 °C), followed by winter (2.15 °C), spring (0.47 °C), and autumn (0.40 °C). Moreover, the annual mean SUHII was stronger at nighttime (1.90 °C) compared to during the daytime (0.84 °C), with variations observed across seasons. The seasonal disparity of SUHII in Xinjiang was more significant during the daytime (3.91 °C) compared to nighttime (0.39 °C), with daytime and nighttime SUHIIs decreasing from summer to winter. The study also highlights that the city size, elevation, vegetation cover, urban form, and socio-economic factors (GDP and population density) emerged as key drivers, with the GDP exerting the strongest influence on SUHIIs in cities across Xinjiang. To mitigate the UHI effects, measures like urban environment enhancement by improving surface conditions, blue–green space development, landscape optimization, and economic strategy adjustments are recommended. Full article

There is growing international interest in assessing population exposure to radiofrequency electromagnetic fields, especially those generated by mobile-phone base stations. The work presented here is an experimental study in which we assess exposure to radiofrequency electromagnetic fields in a university environment, where there is a site with mobile-phone antennas and where a large number of people live on a daily basis. The data were collected with a personal exposure meter in two samplings, one walking at ground level and the other using an aerial vehicle at a height higher than the buildings. The geo-referenced electric-field data were subjected to a process in which a theoretical model was adjusted to the experimental variograms, and heat maps were obtained using kriging interpolation. The research carried out is of great relevance, since it provides detailed measurements of the electromagnetic radiation levels both at ground level and at significant heights, using innovative methodologies such as the use of drones. Furthermore, the results obtained allow for contextualizing the exposures in relation to international safety limits, highlighting the importance of rigorous monitoring in everyday environments. Full article

In this study, we analysed lithospheric, atmospheric, and top-side ionospheric magnetic field data six months before the three earthquake doublets occurred in the last ten years around the Arabian tectonic plate. They occurred in 2014, close to Dehloran (Iran), in 2018, offshore Kilmia (Yemen) and in 2022, close to Bandar-e Lengeh (Iran). For all the cases, we considered the equivalent event in terms of total released energy and mean epicentral coordinates. The lithosphere was investigated by calculating the cumulative Benioff strain with the USGS earthquake catalogue. Several atmospheric parameters (aerosol, SO₂, CO, surface air temperature, surface latent heat flux humidity, and dimethyl sulphide) have been monitored using the homogeneous data from the MERRA-2 climatological archive. We used the three-satellite Swarm constellation for magnetic data, analysing the residuals after removing a geomagnetic model. The analysis of the three geo-layers depicted an interesting chain of lithosphere, atmosphere, and ionosphere anomalies, suggesting a geophysical coupling before the Dehloran (Iran) 2014 earthquake. In addition, we identified interesting seismic accelerations that preceded the last 20 days, the Kilmia (Yemen) 2018 and Bandar-e Lengeh (Iran) 2022 earthquake doublets. Other possible interactions between the geolayers have been observed, and this underlines the importance of a multiparametric approach to properly understand a geophysical complex topic as the preparation phase of an earthquake. Full article

Urban Heat Islands are a major environmental and public health concern, causing temperature increase in urban areas. This study used satellite imagery and machine learning to analyze the spatial and temporal patterns of land surface temperature distribution in the Metropolitan Area of Merida (MAM), Mexico, from 2001 to 2021. The results show that land surface temperature has increased in the MAM over the study period, while the urban footprint has expanded. The study also found a high correlation ($r>$ 0.8) between changes in land surface temperature and land cover classes (urbanization/deforestation). If the current urbanization trend continues, the difference between the land surface temperature of the MAM and its surroundings is expected to reach 3.12 °C ± 1.11 °C by the year 2030. Hence, the findings of this study suggest that the Urban Heat Island effect is a growing problem in the MAM and highlight the importance of satellite imagery and machine learning for monitoring and developing mitigation strategies. Full article

Soil pollution mainly results from particulate matter falling from the atmosphere; for example, PM10 and PM2.5 originate from anthropogenic sources. Krakow is both an industrial and touristic city. The aim of this research was to establish the sources and find the main drivers of trace metal (TM) soil contamination in the recreational city park in Krakow. This study was performed on forest soils and glades located near built-up areas and 100 m above built-up areas. The contents of lead, cadmium, zinc, chromium, organic carbon, total nitrogen, available nutrients, dehydrogenases, urease, and invertase activities in the soils were determined. Geo-accumulation, pollution load, Nemerov pollution indices, and potential ecological risk were calculated. Our results indicated low emissions (house heating and traffic) as the main sources of pollution. TM pollution was higher in the soils of built-up areas than in soils located 100 m above built-up areas, and forest soils were more polluted with TMs than glade soils. Activities undertaken as part of the sustainable development of the city should aim to reduce low emissions. Full article

The objective of this article is to examine potential techniques for suppressing solar heat flow on the optical antenna of a laser communication sensor. Firstly, the characteristics of the geosynchronous Earth orbit’s (GEO) space radiation environment are analysed, and a combined passive and active thermal control solution is proposed. Secondly, the temperature distribution of the lasercom sensor under extreme operating conditions is simulated utilising IDEAS-TMG (6.8 NX Series) software, which employs Monte Carlo and radiative heat transfer numerical calculation methods. Finally, a strategy for avoiding direct sunlight around midnight is proposed. The simulation results demonstrated that the thermal control solution and solar avoidance strategy proposed in this paper achieved long-term fine-stable control of the temperature field of the optical antenna, which met the thermal permissible communication hours per daily orbit cycle in excess of 14 h per day. Full article