Search Results (299)

Climate-induced drought and intensifying land-use pressures threaten ecosystem services and agricultural productivity, particularly in regions with distinctive soil and ecological characteristics. Alabama’s Black Belt, defined by its clay-rich soils and shaped by a legacy of plantation agriculture, uneven land tenure, and persistent socioeconomic disadvantage, is increasingly vulnerable to these interacting stressors. This study analyzes long-term (2000–2023) spatiotemporal patterns of Land Use Land Cover (LULC) change and vegetation response to drought to inform sustainable resource management. Multi-temporal Landsat imagery and National Land Cover Database (NLCD) products were used to quantify LULC dynamics. At the same time, vegetation condition and moisture stress were assessed using the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI). Drought conditions were evaluated using the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI), which incorporates temperature-driven evaporative demand. Results indicate substantial landscape change, including declines in deciduous forest (−17.78%) and pasture/hay (−13.17%), alongside increases in medium-intensity developed land (+20.25%) and evergreen forest (+10.62%). Declining NDVI and NDMI values indicate increasing vegetation stress, particularly during prolonged droughts. Vegetation response exhibited a weak relationship with SPI (R = 0.37) but a stronger association with SPEI (R = 0.59), underscoring the importance of accounting for atmospheric water demand. These findings highlight the growing vulnerability of Black Belt ecosystems to coupled climate and land-use pressures and provide insights to strengthen climate-resilient agricultural management. Full article

Liquefied petroleum gas (LPG) is a widely available alternative fuel, easily stored in liquid form, capable of displacing diesel fuel in compression-ignition engines. Bio-LPG extends this pathway because it is a renewable drop-in form of LPG; its distinguishing advantage is not a different in-cylinder combustion chemistry, but a lower life-cycle greenhouse-gas intensity that depends on feedstock and production route. This review, therefore, combines a systematic synthesis of CI-engine LPG combustion evidence with a Bio-LPG transition perspective. A PRISMA-guided search of major databases (2000–2025) yielded 47 studies with matched diesel baseline. Evidence was categorized by LPG utilization pathway, distinguishing between fumigation, gaseous port injection, and in-cylinder LPG direct injection (gaseous or liquid), alongside engine class, pilot fuel fraction, and key operating parameters (injection timing/quantity, intake conditioning, exhaust gas recirculation (EGR), and boost). Data were normalized as percentage deviations relative to diesel and synthesized across standardized load bins (25/50/75/100%). Among studies reporting nitrogen oxides (NO_x), 20 of 37 showed net reductions, while results in 12 studies were load-dependent; particulate matter (PM), smoke, and soot indicators decreased in 17 of 27 cases. While intake-path strategies generally reduced NO_x and smoke, they often increased CO and HC emissions at low loads. The limited emerging liquid-phase direct-injection evidence shows the closest diesel-like efficiency response, although the evidence base remains limited. Overall, the engine-level findings identify the most promising LPG/Bio-LPG deployment pathways, while the specific additional climate benefit of Bio-LPG lies in its lower well-to-wheel greenhouse-gas intensity. Full article

Methane emissions from end-use installations in residential natural gas systems remain poorly quantified, despite their importance to both safety and climate policies worldwide. While distribution networks and appliances have received research attention, interior piping between the meter and appliances represents a critical knowledge gap. To address this gap, a systematic survey of 473 residential systems in Saarlouis, Germany, was conducted using standardized pressure decay tests (DVGW G 600). Measurements were performed during the installation of gas regulators necessitated by a grid pressure increase from 23 mbar to 55 mbar above ambient. This provided a unique opportunity to assess whole-system leakage under controlled conditions without installation modifications. Leak rates were standardized to reference pressure and converted to methane emissions using measured gas composition, using a linear pressure scaling as a provisional approximation valid for the small pressure differences in the applied test conditions. A total of 411 (86.9%) installations showed no detectable leak rate (LDL: 0.2 $\mathrm{L}{\mathrm{h}}^{-1}$). However, seven systems (1.5%) exceeded 1 $\mathrm{L}{\mathrm{h}}^{-1}$, and one surpassed the unacceptable threshold of 5 $\mathrm{L}{\mathrm{h}}^{-1}$. Mean emissions across all systems were 0.067 [0.041, 0.098] $\mathrm{g}{\mathrm{h}}^{-1}$, with smaller installations showing higher volume-normalized rates. Critically, fewer than 1.48% of systems contributed more than 46% of total emissions, demonstrating a strongly skewed, heavy-tailed distribution. Scaled nationally using Monte Carlo methods accounting for sampling uncertainty and skewed distributions, residential interior piping contributes 12.30 [8.11, 18.55] $\mathrm{G}\mathrm{g}{\mathrm{year}}^{-1}$ to Germany’s methane emissions. These results emphasize the need to include residential leak rates in emission inventories and highlight the efficiency potential of targeted mitigation strategies focused on high-emitting installations under evolving EU methane regulations. Full article

Infrastructure drainage projects play a critical role in urban development but are increasingly exposed to environmental, operational, and climate-related risks that challenge their long-term sustainability. Despite this, decision-makers continue to lack risk-informed, structured methods to assess sustainability performance in an uncertain environment. In order to facilitate evidence-based decision-making and sustainable risk management, this study suggests a risk-informed sustainability index for infrastructure drainage projects. The study first points out a weakness in the methods currently used for sustainability assessments, specifically the lack of risk-sensitive, standardized frameworks designed for drainage infrastructure systems. Altogether, 28 sustainability indicators are identified, with 22 indicators retained after the application of fuzzy set theory criteria. The sustainability index is developed by normalizing, weighting, and combining these indicators using a multi-criteria decision analysis (MCDA) method. To show the usefulness and practicality of the suggested approach in assessing sustainability performance and pinpointing risk-critical improvement areas, it is used for a long-term infrastructure drainage project. In order to improve infrastructure resilience, the findings emphasize the significance of early integration of sustainability and risk considerations, stakeholder engagement, and ongoing performance monitoring. The suggested approach offers a flexible and transferable framework for risk-informed decision-making, assisting engineers, project managers, and policymakers in enhancing the resilience and sustainability of infrastructure drainage systems. Full article

This study develops and applies a Climate–Water–Health (CWH) Nexus Index to compare multi-dimensional risk trajectories across six African Least Developed Countries, namely, Chad, Democratic Republic of Congo, Lesotho, Madagascar, Niger, and Togo, each representing major climatic regions. Using decadal averages for 2000–2009 and 2010–2020, the study constructs three sub-indices—Climate Risk Index, Water Insecurity Index, and Health Burden Index—and then aggregates them into a composite CWH index. Indicators are harmonized via min–max normalization, and water and health measures are expressed per 100,000 population to ensure cross-country comparability under differing population sizes. The results of the study indicate substantial heterogeneity in both levels and drivers of nexus risk. The CWH risk decreased in most countries from the 2000s to the 2010s, while relative positions shifted as improvements occurred unevenly across dimensions. Sensitivity analysis with equal and dimension-focused weights confirms that core country groupings and extremes are robust to plausible weighting schemes. External consistency checks show a strong negative Pearson correlation between the standard CWH and the Human Development Index in both decades, indicating that higher human development is associated with lower Nexus risk. The proposed framework is transparent, scalable, and suitable for extension to broader African coverage and subnational mapping. Full article

Wetlands are vital ecosystems that regulate water, store carbon and support biodiversity, but they are highly vulnerable to climate variability and human pressures. In semi-arid South Africa, montane wetlands remain understudied despite their ecological and socioeconomic importance. The study analyzed 1996–2023 climate variability and vegetation response across the Waterberg Mountain Complex (WMC) using station temperature/precipitation, Rainfall Anomaly Index (RAI), 6-month wet-season Standardized Precipitation Index (SPI) and site-level Normalized Difference Vegetation Index (NDVI) for 11 wetlands. Maximum temperatures increased at all stations, led by Warmbath (0.009 °C/month). No statistically significant changes in minimum temperature were detected. Precipitation trajectories diverged, Mokopane exhibited a statistically significant wetting trend whereas Lephalale and Marken experienced progressive drying. ENSO-driven droughts (2002/2003, 2015/2016 and 2019/2020) intensified hydroclimatic stress and shortened wetland hydroperiods. NDVI trends revealed strong coupling with rainfall variability, with high-altitude wetlands demonstrating greater resilience, while lowland systems declined in greenness. These findings highlight topography as a determinant of wetland vulnerability, positioning upland wetlands as potential climate refugia. Site-specific adaptation and conservation strategies are essential to safeguard ecosystem services and biodiversity, contributing to global sustainability goals (SDGs 6, 13 and 15). Full article

Quaternary ammonium compounds (QACs) have dominated biocidal practice in cultural heritage conservation for decades, yet growing evidence of environmental persistence, aquatic ecotoxicity, and antimicrobial resistance induction has prompted the search for safer alternatives. Essential oils (EO) have emerged as promising bio-based biocides, though their environmental performance has rarely been quantified through rigorous life cycle approaches. This study presents a comparative Life Cycle Impact Assessment (LCIA) of EO-based and QAC-based biocidal formulations across representative conservation scenarios, following ISO 14040/14044 standards and the Environmental Footprint 3.1 methodology with USEtox^® 2.1 characterization factors. Three complementary functional units were employed: formulation-based, surface-based, and intervention-based. The results reveal a fundamental trade-off: EO-based systems exhibit 81% higher climate change impacts but 82–89% lower human toxicity and freshwater ecotoxicity impacts compared to QAC-based systems. Surface-normalized comparisons reduce the climate gap to 32%, while toxicity advantages remain robust across all sensitivity scenarios. Monte Carlo analysis confirms the robustness of toxicity findings (p > 99%), whereas climate comparisons remain scenario-dependent. These findings support context-dependent adoption of EO-based biocides in conservation practice and demonstrate that EO-related climate impacts are technically mitigable, while QAC toxicity is intrinsic to their molecular structure. Full article

Meteorological drought is a major natural hazard in semi-arid regions, where high climate variability and strong dependence on precipitation intensify pressure on water resources and socio-economic systems. This study examined the spatiotemporal characteristics of meteorological drought in the Wadi Sly basin (northwestern Algeria) over the period 1967–2022, using long-term monthly precipitation records from seven meteorological stations. The Standardized Precipitation Index (SPI) was calculated at multiple time scales (1-, 3-, 6-, 9-, and 12-month) to characterize drought onset, severity, persistence, and temporal variability. In addition, drought severity probability and frequency analyses were conducted to evaluate the likelihood and recurrence of different drought classes. The results indicate pronounced inter-annual and decadal variability in drought conditions, with severe and prolonged drought episodes occurring during the mid-1980s, early-to-mid-1990s, and late 2010s. During these periods, SPI values frequently fell below −2.0, signifying extreme drought conditions. Spatial analysis reveals strong basin-wide synchronicity of drought events, suggesting the influence of large-scale atmospheric drivers, although localized variations in drought intensity remain evident. Overall, near-normal conditions dominate the record (accounting for approximately 60–70% of observations), while moderately dry conditions occur more frequently than moderately wet conditions at several stations. Drought characteristics exhibit strong scale dependence, with short-term droughts prevailing at shorter SPI time scales, while longer time scales emphasize drought persistence and accumulation. Overall, the findings indicate an increasing prominence of long-duration drought conditions in recent decades, as evidenced by recurrent low SPI values at longer aggregation scales. Such conditions may pose heightened risks to groundwater recharge processes and long-term water resource availability. Despite the limitations inherent in precipitation-based indices, this study provides a robust statistical framework for drought characterization and contributes valuable insights for improved drought monitoring, early warning systems, and climate-resilient water resource management in semi-arid basins. Full article

Understanding the impact of climate change on tourism is vital for the economies that rely on it. The tourism sector in Croatia, a country with diverse climatic regions, but also diverse features of tourism, is particularly sensitive to changes in climate variables such as 2 m air temperature and precipitation totals. This study analyzes trends in these two key climate variables from 1961 to 2024 across five representative climatic regions: the-mountainous Lika region (Ličko-senjska County), the Kvarner region on the northern Adriatic coast (Primorsko-goranska County), the Zadar region on the central Adriatic coast (Zadarska Counties), and northern continental Croatia (Varaždinska and Međimurje Counties). Linear trends, 5-year moving averages, and comparisons between two standard climate periods (1961–1990 and 1991–2020) were conducted. Using these data, the monthly self-calibrated Palmer Drought Severity Index (sc-PDSI) and Standardized Precipitation Index (SPI) for seven-time scales were calculated for the period 1961–2024 to assess drought conditions and their implications for tourism across the selected destinations. Frequencies of dry, near normal and wet months, estimated by SPI for a nine-month time scale (SPI-9) and a monthly sc-PDSI, were compared for two subperiods, 1961–1992 and 1993–2024. Meteorological data were contextualized for tourism stakeholders, with a focus on adaptation measures. Semi-structured interviews were conducted with tourism professionals in the study regions, providing qualitative insights into observed changes in climate and tourist behavior, operational challenges, adaptation strategies, level of community engagement, and opportunities envisioned. Objective climatological data were compared with the subjective perceptions of tourism experts using the principle of mixed methods, which allows for triangulation. The climatological data indicated a continuous trend of increasing mean annual air temperatures, as well as anomalies of average precipitation amount. The interviews revealed signals of emerging climate shifts, such as changes in the seasonality of visitors, concerns about water scarcity and heat stress. These findings were interpreted in the context of potential threats and opportunities for the tourism sector, highlighting region-specific adaptation strategies. By combining objective climate data with insights from tourism professionals, this study provides a comprehensive assessment of climate change impacts on tourism and informs for resilient tourism development across Croatia’s diverse regions. This paper presents a methodological framework for developing adaptation recommendations that draw on both empirical climate data and the lived experiences of tourism work practitioners. Full article

Black locust (Robinia pseudoacacia L.) breeding is an important component of plantation forestry in Central and Eastern Europe; however, clone trials are still mainly evaluated using conventional field surveys, and the application of high-resolution red-edge satellite indices at the intraspecific level remains rarely applied. As a result, less information is available on the phenological status of black locust clones derived from red-edge satellite data. This study evaluates a clone trial established in Eastern Hungary on slightly acidic Arenosol soil, assessing the growth performance and seasonal spectral dynamics of newly bred black locust clones during their fifth growing season by integrating field measurements with PlanetScope-derived Normalized Difference Red-Edge Index (NDRE) time series. Clone NK2 exhibited the most vigorous growth, reaching a mean height of 11.1 ± 0.15 m and a diameter at breast height (DBH) of 11.21 ± 0.19 cm, which were 35.4% greater in height and 19.0% larger in DBH than those (8.2 ± 0.12 m height, and 9.42 ± 0.23 cm diameter) of the control (‘Üllői’ cultivar). Clone PL251 also exceeded the control by 25.6% in height and 19.2% in DBH. Spectral analysis (NDRE value ± standard error) revealed marked differences in phenological development: in the early stage (April 15), NK1 and PL040 had the highest NDRE values (0.472 ± 0.020 and 0.461 ± 0.019), whereas NK2 showed delayed leaf emergence (0.398 ± 0.019). By June 21, PL251 had reached an NDRE value of 0.692 ± 0.013, which was higher than that of the control (0.673 ± 0.016). In mid-July, NDRE peaked for NK2 and NK1 (0.732 ± 0.012 and 0.731 ± 0.013), with ‘Üllői’ showing consistently lower values across the season. In the final stage, NK2 maintained the highest NDRE values (October 22: 0.618 ± 0.015; November 9: 0.466 ± 0.021), indicating prolonged photosynthetic activity, while NK1 and ‘Üllői’ declined earlier (e.g., November 9: 0.354 ± 0.018 and 0.390 ± 0.027, respectively). These findings highlight NK2 and PL251 as superior candidates for high-yield, climate-resilient tree plantations because of their strong growth and extended physiological activity. Full article

Wetlands have been recognized as nature-based solutions to the climate crisis. This study evaluates the state of standardization in nationwide inland wetland survey datasets and analyzes terrestrial vertebrate patterns by integrating datasets with public environmental data. Species richness data for amphibians/reptiles (432 wetlands), birds (1183 wetlands), and mammals (72 wetlands) were compiled from 134 reports published between 2000 and 2021. Using generalized linear models (GLMs) and generalized additive models (GAMs), we assessed how 15 explanatory variables (climate, topography, wetland information, land use, and water quality) relate to species richness. Model families were chosen for each taxonomic group, and variables were selected using the Akaike information criterion (AIC) and ecological plausibility. Deviance explained was 55.5% for amphibians/reptiles, 60.1% for birds, and 52.4% for mammals. Wetland area and Normalized Difference Vegetation Index (NDVI) were positively associated with species richness across all groups. Despite the large volume of survey data, inconsistent reporting formats and limited metadata constrain longitudinal and time series analyses. Standardized protocols and metadata management are therefore needed to build a systematic national database that can support wetland ecological modeling and conservation policy. Full article

Accurately determining actual energy consumption is essential for guiding technological developments in the transport sector, assessing vehicle development outcomes, and designing effective energy and climate policies. Although laboratory driving cycles such as the WLTP provide standardized benchmarks, they do not reflect the complex interactions between human behavior, environmental conditions, and vehicle dynamics under real-world operating conditions. This article presents an integrated framework for assessing long-term, actual energy carrier consumption in four main vehicle categories: internal combustion engine vehicles (ICEVs), hybrid electric vehicles (HEVs), hydrogen fuel cell electric vehicles (H2EVs), and battery electric vehicles (BEVs). The entire discussion here is based on the results of data analysis from natural operation using the so-called vehicle energy footprint. This framework provides a method for determining the average energy carrier consumption for each group of vehicles with the specified drivetrains. This information formed the basis for assessing the total energy demand for the operation of the analyzed vehicle types in normal operation. The simulations show that among mid-range passenger vehicles, ICEVs are the most energy-intensive in normal operation, followed by H2EVs and HEVs, and BEVs are the least. This study highlights the methodological challenges and implications of accurately quantifying energy consumption. The presented method for assessing energy demand in vehicle operation can be useful for manufacturers, consumers, fleet operators, and policymakers, particularly in terms of energy efficiency, emission reduction, and public health protection. Full article

Droughts are recognized as one of the most devastating extreme climate events, leading to severe socioeconomic losses and ecological degradation globally under climate change. With global warming, the frequency and intensity of extreme droughts are increasing, posing critical challenges to water resource management. The Standardized Precipitation Conversion Index (SPCI) has demonstrated potential in drought monitoring; however, its applicability across diverse climatic zones and multiple temporal scales remains inadequately validated. This study addresses this gap by establishing a novel multi-scale inversion analysis using ERA5-based precipitable water vapor (PWV) and precipitation data. SPCI is selected for its advantage in eliminating climatic background biases through probability normalization, overcoming limitations of traditional indices such as the Standardized Precipitation Index (SPI) and Standardized Precipitation-Evapotranspiration Index (SPEI). We systematically evaluated the spatiotemporal evolution of Precipitation Efficiency (PE) and SPCI across four climatic zones in China. Results show that the first two principal components explain over 85% of the spatiotemporal variability of PE, with PC1 independently contributing from 82.05% to 83.80%. This high variance contribution underscores that the spatiotemporal patterns of PE are dominated by a few key climatic drivers, validating the robustness of the principal component analysis. SPCI exhibits strong correlation with SPI, exceeding 0.95 in the Tropical Monsoon Zone (TMZ) at scales of 1–6 months, indicating its utility for short-to-medium-term drought monitoring. Distinct zonal differentiation in PE patterns is revealed, such as the bimodal annual cycle in the Tropical-Subtropical Monsoon Composite Zone (TSMCZ). This study evaluates the performance of the SPCI against the widely used SPI and SPEI across four major climatic zones in China. It validates the SPCI’s applicability across China’s complex climates, providing a scientific basis for region-specific drought early warning and water resource optimization. Full article

River ecosystems play a crucial role in the global water cycle and regional ecological security, yet they face severe challenges under the dual pressures of human activities and climate change. To systematically assess the spatiotemporal characteristics and driving mechanisms of river ecological impacts, this study proposes a modular and transferable method, which is Quantitative Analysis of Spatiotemporal Variations in Ecological Water-Supplementation Benefits of Rivers Based on Remote Sensing (QASViewSBR). Taking the Yongding River (Beijing section) from 2016 to 2023 as a case study, this research integrates multi-source remote sensing and ground monitoring data to extract river water bodies using an improved Normalized Difference Water Index and Vertical–Horizontal polarization characteristics. The Seasonal and Trend decomposition using Loess (STL) method was employed for time-series trend decomposition, Pearson correlation analysis was applied to identify driving factors of area changes, and the Pelt algorithm was used to quantify the response range of riparian vegetation to changes of river water levels. An integrated analytical framework of “dynamic monitoring—time series analysis—driving factor identification—spatial heterogeneity assessment” was established, enabling standardized end-to-end analysis from data acquisition to evaluation. The results indicate that the river water area in the basin increased significantly after 2019, with enhanced seasonal fluctuations. Under the ecological water supplementation policy, the “human-initiated, natural-response” mechanism was clearly observed, and the ecological responses along both riverbanks exhibited significant spatial heterogeneity due to variations in surface features and topography. QASViewSBR exhibits good universality and transferability, providing methodological support for ecological restoration and management in different river basins. Full article

To address the issue of climate change caused by greenhouse gases, extensive research has been conducted on technologies for separating and capturing carbon dioxide. This study aimed to investigate the internal flow behavior and relative spatial distribution of CO₂-related features inside a vortex tube using the Schlieren method. Due to the presence of numerous components in a typical counter-flow vortex tube that may cause optical refraction along the measurement path, a simplified tube with a single nozzle was designed and manufactured for the experiments. The experiments consisted of CO₂ single-phase flow and air–CO₂ mixture flow tests. Images captured during the experiments were processed using Gaussian filtering and background correction to enhance the visibility of boundary layers and internal flow structures. Based on the pixel intensity values of the processed Schlieren images, relative intensity distributions associated with CO₂-related flow behavior inside the tube were estimated and visualized. The experimental results revealed that, in both CO₂ single-phase and air–CO₂ mixture flows, regions of relatively high Schlieren intensity consistently appeared at specific locations within the tube. These observations indicate that the internal flow structure and relative distribution patterns are sensitive to the local flow features near the nozzle region under the tested conditions. The temporal evolution of the normalized Schlieren pixel intensity and its standard deviation was quantitatively evaluated, in a relative sense, to characterize the development of vortex flow structures under different operating conditions. The proposed visualization and analysis framework provides a systematic qualitative approach, supported by relative quantitative indicators, for investigating vortex-induced flow behavior. This framework may serve as a foundation for future studies that integrate complementary diagnostics and numerical analyses to further explore the vortex-based gas separation mechanism. Full article