Search Results (44)

The Eastern Mediterranean region is experiencing accelerated climate warming, yet localized patterns remain poorly understood, particularly in areas with complex topography. This study examines long-term air temperature trends from 1992 to 2024 at two sites in Lebanon: Beirut Airport (urban–coastal) and Houch Al Oumaraa station in Zahlé (inland–valley). Using homogeneity testing, linear regression, and the Mann–Kendall trend test, we assess trends in minimum, maximum, and mean temperatures. The results show a strong and statistically significant warming trend in Beirut, with mean temperatures rising by +0.536 °C per decade and minimum temperatures showing the steepest increase (+0.575 °C/decade). In Zahlé, the warming trend is less pronounced, particularly for maximum temperatures (+0.369 °C/decade), while minimum temperatures increased by +0.528 °C/decade. Data from fixed stations and drone-based vertical profiling in Zahlé confirmed the presence of cold-air pooling and thermal inversions, which moderate air temperatures and may contribute to a subdued warming trend. The strongest inversion recorded in 2022 reached 6.7 °C between ground level and an altitude of 500 m. In contrast, the urban heat island (UHI) effect in Beirut and Zahlé appear to drive nighttime warming, particularly in summer and early autumn months. These findings highlight the roles of topography and urbanization in shaping local climate trends. Full article

The Arctic is the fastest-warming region on Earth, exhibiting a pronounced “amplifying effect”, which has triggered widespread permafrost thaw and increased the risk of surface deformation. In the Arctic coastal lowlands, permafrost is also affected by shoreline retreat. The impact of these dual stressors on surface deformation processes in the Arctic coastal lowlands remains poorly understood, particularly in terms of how permafrost thaw and shoreline retreat interact to influence surface stability. To address this gap, we employed PS-InSAR technology to monitor surface deformation from 2017 to 2021 at Tiksi Airport, the northernmost airport on the Siberian mainland, situated adjacent to the Laptev Sea. The results show that Tiksi Airport experiences localized significant surface subsidence, with deformation velocity ranging from −42 to 39 mm/yr. The near-coastal area of Tiksi Airport is strongly influenced by the ocean. Specifically, for extreme subsidence deformation (around –40 mm/yr), the surface subsidence velocity increases by 0.2 mm/yr for every 100 m closer to the coastline. Analysis of these deformation characteristics suggests that the primary causes of subsidence are land surface temperature (LST) warming and erosion by the Laptev Sea, which together lead to increased permafrost thaw. By revealing the combined effects of climate warming and coastal erosion on permafrost stability, this study contributes to enhancing the understanding of infrastructure safety and quality of life for residents in Arctic coastal subsidence areas. Full article

The goal of “double carbon” puts forward higher requirements for the control of transport carbon emissions, and the exploration of transport carbon emission modelling driven by big data is an important attempt to reduce carbon accurately. Based on the land Vehicle Miles Traveled data (VMT) and the sea Automatic Identification System (AIS) data, this study establishes a refined, high-resolution carbon emission measurement model that incorporates the use of motor vehicles and ships from a bottom-up approach and analyzes the spatial distribution characteristics of land and sea transport carbon emissions in Tianjin using geospatial analysis. The results of the study show that (1) the transportation carbon emissions in Tianjin mainly come from land road traffic, with small passenger cars contributing the most to the emissions; (2) high carbon emission zones are concentrated in economically developed, densely populated, and high road network density areas, such as the urban center Binhai New Area, and the marine functional zone of Tianjin; (3) carbon emission values are generally higher in the segments where ports, airports, and interchanges are connected. The transportation carbon emission measurement model developed in this study provides practical, replicable, and scalable insights for other coastal cities. Full article

Settlement issues at airports pose a significant threat to operational safety, particularly in coastal regions, where land reclamation introduces unique challenges. The complexities of marine foundations, the difficulties in investigating reclaimed land, and the heightened risks of excessive settlement require timely and accurate monitoring and prediction to effectively identify risks and minimize unnecessary maintenance costs. To address these challenges, this study introduces a dynamic prediction model based on grey system theory, enhanced by a variable-size sliding window mechanism that continuously integrates the latest monitoring data. Validation using datasets from Kansai International Airport and Xiamen Xiang’an International Airport demonstrates that the model improves prediction accuracy by over 20% compared to existing models. Additionally, an exponential forecasting mechanism for long-term settlement prediction is developed and verified with data from Pudong International Airport. The proposed model demonstrates robust predictive capabilities across both long-term and short-term forecasting scenarios. Full article

Per- and polyfluoroalkyl substances (PFAS) are increasingly detected in remote environments. This review aims to provide a comprehensive overview of the types and concentrations of PFAS found in the air, water, soil, sediments, ice, and precipitation across different remote environments globally. Most of the recent studies on PFAS remote occurrence have been conducted for the Arctic, the Antarctica, and the remote regions of China. Elevated perfluorooctane sulfonate (PFOS) in Meretta and Resolute Lakes reflects the impact of local sources like airports, while PFAS in lakes located in remote regions such as East Antarctica and the Canadian High Arctic suggest atmospheric deposition as a primary PFAS input. Long-chain PFAS (≥C7) accumulate in sediments, while short-chain PFAS remain in water, as shown in Hulun Lake. Oceanic PFAS are concentrated in surface waters, driven by atmospheric deposition, with PFOA and PFOS dominating across oceans due to current emissions and legacy contamination. Coastal areas display higher PFAS levels from local sources. Arctic sediment analysis highlights atmospheric deposition and ocean transport as significant PFAS contributors. PFAS in Antarctic coastal areas suggest local biological input, notably from penguins. The Tibetan Plateau and Arctic atmospheric data confirm long-range transport, with linear PFAS favoring gaseous states, while branched PFAS are more likely to associate with particulates. Climatic factors like the Indian monsoon and temperature fluctuations affect PFAS deposition. Short-chain PFAS are prevalent in snowpacks, serving as temporary reservoirs. Mountainous regions, such as the Tibetan Plateau, act as cold traps, accumulating PFAS from atmospheric precursors. Future studies should focus on identifying and quantifying primary sources of PFAS. Full article

This study aimed to characterize the temporal and spatial occurrence of microplastics on the beaches of the Caribbean coast of Limón, Costa Rica. The selected beaches comprise a stretch of 70 km, characterized by large environmental protection areas, agricultural and residential areas with low occupation density, urban areas, and port areas. Despite the great importance of the beaches for the country, studies related to solid waste pollution remain scarce on the Caribbean coast. The methodology consisted of conducting fieldwork in 2017 and 2019 to collect materials on five beaches and laboratory analyses for extraction using hypersaline solution and the quantification and characterization of microplastics based on type, size, and color. The results show that the beaches studied in the northwestern sector had the highest concentrations of microplastics, with emphasis on Cieneguita Beach and Airport Beach, with a predominance of pellets (56.7%) followed by fragments (21.8%). These beaches are inserted in a coastal stretch with a strong concentration of industrial, port, and airport activities. The lower occurrence of microplastics in the southeastern sector (Manzanillo and Gandoca) may be related to the greater number of preservation areas. With varying sizes, shapes, and colors, most microplastics had a worn appearance, which suggests reworking by coastal processes and subsequent deposition on the studied beaches. The impact of this type of pollution on the coast of Limón is notorious and shows the need for further research into the occurrence and distribution of microplastics on Caribbean beaches so that possible sources and damage to coastal ecosystems can be identified. Full article

Water-soluble inorganic ions (WSIIs) can increase the hygroscopicity of aerosols, which will transform aerosols into larger sizes and reduce visibility by enhancing light scattering. To explore the characteristics of WSII concentrations and their impacts on visibility in a coastal airport, in this study, PM_1.0 samples at two monitoring sites (including airport site and background site) were collect in spring and summer, and 12 species of ions were detected. In general, secondary water-soluble inorganic ions (SNA, including ${\mathrm{SO}}_4^{2-}$, ${\mathrm{NO}}_3^{-}$ and ${\mathrm{NH}}_4^{+}$) and ${\mathrm{Ca}}^{2+}$ were the dominant WSIIs in PM_1.0, contributing about 89% to 95% of the total measured ions. The continental contributions of ${\mathrm{SO}}_4^{2-}$, ${\mathrm{K}}^{+}$, and ${\mathrm{Ca}}^{2+}$ accounted for more than 60% during the whole period, while Na⁺ and ${\mathrm{Cl}}^{-}$ were mainly from marine sources. The source identification showed that airport emissions were a major source at the sampling site and significantly contributed to the levels of sulfate, nitrate, and ammonium. Agricultural activities were the dominant sources impacting visibility in spring, while airport emissions and secondary inorganic aerosols were the main components affecting visibility in summer. Therefore, improving atmospheric visibility in coastal airport areas should focus on reducing the precursors of secondary particulates and reducing biomass-burning activities. Full article

Tourism has emerged as a pivotal element of China’s economic development, particularly within its coastal cities. This paper presents a comprehensive analysis of China’s coastal city tourism economic development, focusing on 53 coastal cities. Through a meticulous combination of literature analysis and data crawling, a robust database is constructed, encompassing tourism resources and revenues. This study delineates the spatial–temporal evolution pattern of China’s coastal city tourism development and employs geo-detector methods to quantitatively analyze the impact factors driving this evolution. Key findings reveal distinct trends in the coastal tourism economy of China from 2009 to 2019, characterized by spatial stability, similar trends in adjacent spatial units, and localized spatial structures. Notably, factors such as actual foreign investment, the presence of star-rated guesthouses, tourism industry employment, airport activity, and import–export trade volume exert significant influence on the domestic tourism economy. Similarly, tourism employment, airport activity, availability of star-rated hotels, import–export trade, and utilization of foreign capital emerge as influential factors shaping inbound tourism. Policy recommendations emphasize the need for government intervention to optimize tourism development strategies for coastal cities. This entails balancing resource exploitation with environmental protection and enhancing the quality of tourism services, fostering sustainable growth and long-term prosperity. Full article

The increase in the quantity and variety of contaminants generated during routine airport infrastructure maintenance operations leads to a wider range of pollutants entering soil and surface waters through runoff, causing soil erosion and groundwater pollution. A significant developmental challenge is ensuring that airport infrastructure meets high-quality environmental management standards. It is crucial to have effective tools for monitoring and managing the volume and quality of stormwater produced within airports and nearby coastal areas. It is necessary to develop methodologies for determining a wide range of contaminants in airport stormwater samples and assessing their toxicity to improve the accuracy of environmental status assessments. This manuscript aims to showcase the latest advancements (2010–2024 update) in developing methodologies, including green analytical techniques, for detecting a wide range of pollutants in airport runoff waters and directly assessing the toxicity levels of airport stormwater effluent. An integrated chemical and ecotoxicological approach to assessing environmental pollution in airport areas can lead to precise environmental risk assessments and well-informed management decisions for sustainable airport operations. Furthermore, this critical review highlights the latest innovations in remediation techniques and various strategies to minimize airport waste. It shifts the paradigm of soil and water pollution management towards nature-based solutions, aligning with the sustainable development goals of the 2030 Agenda. Full article

Coastal areas are frequently impacted by anthropogenic pollution, due to intense human activity in these zones. Our study aimed to monitor the impacts of anthropogenic pollution in four Portuguese locations on the northwest coast, and to identify the most affected areas and/or seasons by applying a multi-biomarker approach. Water and specimens of Phorcus lineatus were collected on the rocky shore during low tide in four sites along the northwest Portuguese coast (1. Amorosa; 2. Cabo do Mundo; 3. Homem do Leme; 4. S. Félix da Marinha) with different anthropogenic pressures, including an industrial maritime shipyard; an oil refinery; an international airport; and an area with high human population density. The collection took place over two seasons: the summer of 2021 and the winter of 2022. Several biochemical biomarkers, including reactive oxygen species; protein carbonyl content; lipid peroxidation (LPO); carboxylesterase (CE); and antioxidant (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and neurotoxicity—acetylcholinesterase (AChE)) enzymes were measured. The results showed seasonal variation, with the ROS, LPO, CE, and GST activities depending particularly on the season, but the SOD and CAT activities being similar between summer and winter. CAT showed lower activity in Site 1 than in the other sites during both seasons (p < 0.05). The Integrated Biomarker Response (IBR) index showed that biomarker responses were higher in winter. The multivariate analysis confirmed the higher contribution of the factor season to the P. lineatus’ response to pollutants, compared to the spatial variation in the northwest Portuguese coast. Overall, this study shows that P. lineatus can be a suitable bioindicator species for environmental biomonitoring, and that the IBR index allows the identification of temporal contamination patterns. Full article

This study conducts a detailed 23-year analysis of Density Altitude (DA) at 34 major airports across China, utilizing Meteorological Aviation Routine Weather Report (METAR) datasets, and discovers significant regional DA variations due to the country’s diverse topography and climate. Central and eastern regions exhibit higher DA values because of lower atmospheric pressures at higher altitudes, while northeastern airports have lower DA values, attributed to colder temperatures and lower elevations. A crucial finding is the substantial impact of humidity on DA, particularly in the southern coastal regions, a factor often neglected in pilot training, highlighting the necessity to revise aviation education to include humidity’s impact on DA. The study advocates for a region-specific approach to Chinese aviation operations, tailored to local DA influences, and suggests strategic adjustments in flight planning and risk assessment to address these regional differences, enhancing aviation safety and efficiency. Full article

Airport pavements are prone to early defects during the construction phase, and their early performance during the construction phase is significantly affected by the external temperature field. This article takes the concrete pavement of Xiamen Xiang’an New Airport as an example and uses a three-dimensional (3D) humidity simulation program for cement concrete pavement to study the evolution behavior of the early stage humidity field of the pavement in a humid and hot climate environment. The results indicate that the evolution law of the humidity field of the concrete pavement slab was consistent with the environmental field, presenting a 24 h periodic variation. The environmental field had a significant impact on the humidity of the surface layer of the pavement slab, and the humidity decreased rapidly with time. There was a humidity gradient on both the horizontal plane and the cutting plane of the slab, the horizontal humidity was concentrated from the boundary into the middle of the slab, and the sectional humidity was concentrated from the top to the bottom of the slab. Environmental parameters, construction parameters, and material and structural parameters all influenced humidity through humidity exchange or by changing the saturated vapor pressure inside the slab. The humidity field was most sensitive to environmental humidity and maintenance methods, but less sensitive to material parameters and structural parameters. Through analysis, it is advisable to avoid hot seasons, choose periods of increased environmental humidity, adopt appropriate maintenance methods during construction to reduce humidity stress on the slab, and therefore decrease early stage deterioration and improve service life. Full article

Sewer Treatment Plants (STPs) are essential pieces of infrastructure given the growing scarcity of water sources due to the challenges of urbanization. The positioning of STPs is a complex multidimensional process that involves integrative decision-making approaches that consider multiple sustainability criteria to ensure their optimal placement. The Multi-Criteria Decision Method (MCDM) is a suite of approaches available to decision-makers when making systematic and scientifically informed decisions on siting wastewater treatment plants. Although MCDM methods have manifold applications in different geographic contexts, there is a paucity of studies employing MCDM models for the siting of STPs within the context of Oman. In this study, we assessed the locations of existing STPs and identified suitable locations for future STPs within the Muscat Governorate of Oman using a Multi-Criteria Decision-Making Analytic Hierarchy Process (MCDM-AHP) model in a Geographic Information System (GIS) environment. Eight factors were considered in the MCDM-AHP model: slope, elevation, proximity to built-up areas, airports, valleys, road networks, the sea, parks, and golf courses. Each factor was assigned priority weights based on its importance using the AHP method. Thematic maps were generated to categorize the potential sites into different suitability levels. The results showed that the coastal areas of A’Seeb and Bowsher were the most suitable locations for STPs, representing only 1.19% of the total study area. The novelty of this study stems from the perspective of an original application within the context of Oman, which has generated novel results and interpretations. This has significant implications for urban policy and planning with respect to better informing decision-makers with a systematic framework for efficient wastewater treatment. Full article

Cities are often hotspots for biological invasions, showing much higher percentages of alien species than non-urbanized settings. The reasons are multiple and are mostly related to two main factors: their heterogeneous, highly disturbed habitats and their many gateways that allow alien species introduction (e.g., airports, roads, train stations, or gardens). In addition to being a sink of biological invasions, cities can also be a source of the spread of alien species into surrounding landscapes, which adds further complexity to this issue. Herein, we are presenting the results of a five-year survey of the alien flora of Montjuïc, the largest urban hill in Barcelona (Spain). In just about 3.4 km², we recorded up to 247 alien plant taxa, a figure much higher than those of many other Mediterranean cities and which clearly points to the role of Montjuïc as a hotspot for alien plants. The comparison with the alien flora of its surrounding region (coastal Catalonia) suggests that the alien flora of Montjuïc would have become enriched through many immigration episodes from close geographic areas. The hill, however, would have also acted as a source of the spread of alien plants, and indeed, some species have not been detected yet beyond the confines of Montjuïc. This study aims to be a key tool to ensure early detection and also to develop appropriate management and/or eradication actions. Full article

Hong Kong International Airport (HKIA) is an important sea airdrome in China. The aim of this study is to evaluate the impacts of this reclamation on the water quality of the Northwestern Bay of Hong Kong (NWBHK). In all, 117 Landsat 5 TM and 44 Landsat 8 OLI images were preprocessed and matched with the marine water data of 18 in situ monitoring points, acquiring 458 and 119 sets of data, respectively. This study adopted BPNN Machine Learning methods to establish the retrieval algorithm. Based on the images, the construction of HKIA was divided into three stages: (1) the construction of the first and second runways from 1992 to 1995; (2) the construction of the Hong Kong Port from 2013 to 2016; and (3) the construction of the third runway from 2017 to 2020. The concentrations of suspended particulate matter, orthophosphate phosphorus, and dissolved inorganic nitrogen from 1986 to 2022 were retrieved. In this paper, it was found that (1) the construction activities led to an increase in SPM, PO₄P, and DIN concentrations in adjacent water bodies; (2) the impact of the Tuen Mun River on the NWBHK increased, while the impact of the Tung Chung River on the NWBHK decreased; and (3) the interception impact of HKIA on the transportation of the Pearl River water became stronger. Full article