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1.
Sci Rep ; 14(1): 20605, 2024 09 04.
Article de Anglais | MEDLINE | ID: mdl-39232057

RÉSUMÉ

For the recently legalized US hemp industry (Cannabis sativa), cross-pollination between neighboring fields has become a significant challenge, leading to contaminated seeds, reduced oil yields, and in some cases, mandated crop destruction. As a step towards assessing hemp cross-pollination risk, this study characterizes the seasonal and spatial patterns in windborne hemp pollen dispersal spanning the conterminous United States (CONUS). By leveraging meteorological data obtained through mesoscale model simulations, we have driven Lagrangian Stochastic models to simulate wind-borne hemp pollen dispersion across CONUS on a county-by-county basis for five months from July to November, encompassing the potential flowering season for industrial hemp. Our findings reveal that pollen deposition rates escalate from summer to autumn due to the reduction in convective activity during daytime and the increase in wind shear at night as the season progresses. We find diurnal variations in pollen dispersion: nighttime conditions favor deposition in proximity to the source, while daytime conditions facilitate broader dispersal albeit with reduced deposition rates. These shifting weather patterns give rise to specific regions of CONUS more vulnerable to hemp cross-pollination.


Sujet(s)
Cannabis , Pollen , Saisons , Vent , États-Unis , Pollinisation
2.
PLoS One ; 19(9): e0308449, 2024.
Article de Anglais | MEDLINE | ID: mdl-39236026

RÉSUMÉ

The impact of the topological formation of wind farms upon the lightning induced overvoltages injected into the grid was not covered earlier in literature. However, this topic is highly important to be investigated to allow the usage of the most reliable topology against lightning strikes. For such reason, the paper investigates this point with consideration of most damaging cases as lightning strikes to multi-blades. The testing used ATP software for four main topologies, radial, single-sided ring SSR, double sided ring and star topology. The features defining the similarities in response and the variance range between these topologies were recorded and analyzed. The multi-blade strikes gave an expected increase of 15% to 100% in the injected overvoltage to the grid for all topologies. The star topology showed the most reliable performance by allowing the least injected overvoltage to the grid. The percentage of reduction in the magnitude of the injected overvoltages reached 50.78%, 66.07% and 89.04% for SSR, DSR and star topology respectively with respect to radial topology. Recommendation was provided for design engineers to consider star topology during design phase in terms of more reliable lightning protection.


Sujet(s)
Vent , Éclairs , Logiciel , Modèles théoriques , Centrales énergétiques
3.
Water Environ Res ; 96(9): e11127, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39254095

RÉSUMÉ

Thermal stratification can cause various water quality issues in large water bodies. To address this, a new wind-powered artificial mixing system is designed and experimentally tested for various Savonius rotor combinations (three-stage and four-stage rotors). These turbines directly utilize wind energy to draw air into the water column for aeration, bypassing the need for electrical conversion. The rotor performances were tested in terms of power and torque coefficients. Additionally, these rotors were tested for artificial mixing efficiencies in a specially designed water tank that can mimic thermal stratification typically observed in an actual water supply reservoir. Among the rotors, the three-stage rotor with a 60° phase shift was found to exhibit superior power and torque coefficients, achieving a power efficiency value of 0.14. As for the mixing efficiency, the four-stage rotor with a 45° phase shift excelled in mixing efficiency, reaching 95%. PRACTITIONER POINTS: A new wind-powered artificial mixing system is designed and tested for various Savonius rotor combinations. While keeping the total rotor height constant, the three-stage Savonius rotor class shows superior performance against the four-stage Savonius rotor class in terms of power and torque efficiency. Apart from the rotor performance results, the four-stage Savonius rotors show greater artificial mixing efficiency than the three-stage Savonius rotors. Single-pump/diffuser artificial destratification system exhibits better mixing efficiency than multiple-pump/diffuser systems.


Sujet(s)
Lacs , Vent , Température , Alimentation en eau , Air
4.
Environ Monit Assess ; 196(10): 890, 2024 Sep 04.
Article de Anglais | MEDLINE | ID: mdl-39230831

RÉSUMÉ

One of the primary causes of urban atmospheric particulate matter, which is harmful to human health in addition to affecting air quality and atmospheric visibility, is road dust. This study used online monitoring equipment to examine the characteristics of road dust emissions, the effects of temperature, humidity, and wind speed on road dust, as well as the correlation between road and high-space particulate matter concentrations. A section of a real road in Jinhua City, South China, was chosen for the study. The findings demonstrate that the concentration of road dust particles has a very clear bimodal single-valley distribution throughout the day, peaking between 8:00 and 11:00 and 19:00 and 21:00 and troughing between 14:00 and 16:00. Throughout the year, there is a noticeable seasonal change in the concentration of road dust particles, with the highest concentration in the winter and the lowest in the summer. Simultaneously, it has been discovered that temperature and wind speed have the most effects on particle concentration. The concentration of road dust particles reduces with increasing temperature and wind speed. The particle concentrations of road particles and those from urban environmental monitoring stations have a strong correlation, although the trend in the former is not entirely consistent, and the changes in the former occur approximately 1 h after the changes in the latter.


Sujet(s)
Polluants atmosphériques , Pollution de l'air , Villes , Poussière , Surveillance de l'environnement , Matière particulaire , Emissions des véhicules , Chine , Poussière/analyse , Polluants atmosphériques/analyse , Matière particulaire/analyse , Pollution de l'air/statistiques et données numériques , Emissions des véhicules/analyse , Saisons , Vent , Température
5.
Ying Yong Sheng Tai Xue Bao ; 35(7): 1815-1824, 2024 Jul 18.
Article de Anglais | MEDLINE | ID: mdl-39233410

RÉSUMÉ

Exploring the physical fractions of organic carbon and influencing mechanisms in grassland, forest, and farmland soils in wind erosion area can provide scientific basis for carbon sequestration, land utilization, wind prevention measure making, and fertility restoration of sloping farmland in the region. We examined the differentiation of aggregate organic carbon and density fractionation organic carbon in 0-15 cm soil layer across grassland, forest, and sloping farmland with 350 m long and 5° slope gradient in the wind erosion area of Meilisi District, Qiqihar, Heilongjiang, as well as the sloping farmland in the downhill section, middle section, and uphill section with every 100 m apart from the bottom to the top. The results showed that soil aggregates >2 mm were all destroyed across grassland, forest, and farmland soils, while the percentage of aggregates <0.053 mm was significantly higher than that of other sizes. The percentage of various soil aggregates, organic carbon content from density fractionations, and the proportion of organic carbon in the heavy fraction aggregates in farmland were significantly lower than that in grassland and forest soils. Soil aggregates in the uphill section of farmland were completely destroyed, and organic carbon content in various size aggregates and density fractionations gradually decreased with increasing slope. The proportion of organic carbon in the heavy fraction aggregates decreased, but that in light fraction aggregates increased gradually. Soil organic carbon and available potassium were key factors affecting aggregate stability, aggregate organic carbon content, and organic carbon content in density fractionations, while the loss of organic carbon in aggregate led to a decrease in aggregate stability. In summary, compared with grassland and forest soils, the stability of soil aggregates, the aggregate organic carbon content, the organic carbon content in density fractionations, and the proportion of organic carbon in heavy fraction aggregates in farmland all decreased in the wind erosion area of Northeast China. With the increases of slope, the aggregate organic carbon content, the organic carbon content in density fractionations, and the proportion of organic carbon in the heavy fraction aggregates in sloping farmland all decreased. Planting trees, conserving and expanding grassland area, and increasing the application of organic materials in sloping farmland in wind erosion area are effective approaches to stabilize and increase carbon storage, improve soil structure, and enhance soil quality.


Sujet(s)
Carbone , Composés chimiques organiques , Sol , Vent , Chine , Carbone/analyse , Carbone/composition chimique , Sol/composition chimique , Composés chimiques organiques/analyse , Produits agricoles/croissance et développement , Prairie , Érosion du sol , Forêts , Arbres/croissance et développement , Poaceae/croissance et développement , Conservation des ressources naturelles , Écosystème
6.
Ying Yong Sheng Tai Xue Bao ; 35(7): 1877-1886, 2024 Jul 18.
Article de Anglais | MEDLINE | ID: mdl-39233417

RÉSUMÉ

Investigating the wind speed flow field and aerodynamic characteristics of shelterbelts with different structural features is of significant importance for the rational arrangement of shelterbelts and the mitigation of wind-blown sand disasters. Considering five cross-sectional shapes of shelterbelts (rectangle, windward right-angle triangle, leeward right-angle triangle, isosceles triangle, and parabolic) and four layout forms (single shelterbelt, L-shaped network, U-shaped network, and rectangular network), we conducted computational fluid dynamics (CFD) simulations using the large eddy simulation (LES) turbulence model to understand mean wind speed flow field and turbulence structure of shelterbelts with different structural features, and investigated the effects of shelterbelt cross-sectional shapes and layout forms on windbreak indicators, such as protection distance and area. We considered tree canopies as porous media and conducted simulation with the 'Tsujimatsu' shelterbelt in Japan with a total height (H) of 7 m, canopy height of 5.8 m, and a canopy base width of 2 m. The results showed that the average relative errors of mean wind speed and turbulent kinetic energy at different heights obtained by numerical simulations and field measurement were small, being 5.5% and 12%, respectively, indicating that the porous medium canopy model successfully reproduced the mean wind speed and turbulent kinetic energy in the leeward area of the shelterbelt. The rectangular cross-section shelterbelt, with the largest canopy volume, significantly obstructed airflow. The mean wind speed and turbulent kinetic energy showed a notable reduction in the leeward area near the shelterbelt, especially in the upper region (z≥0.5H, where z denoted the height), showing the largest protection range. The parabolic cross-section shelterbelt ranked second in terms of protection range, followed by shelterbelts with windward right-angle, leeward right-angle, and isosceles triangular cross-sections. In the downstream area where horizontal distance x≥10H, the mean wind speed and turbulent kinetic energy of shelterbelts with different cross-sectional shapes tended to be the same. Comparing the flow field structures of single shelterbelts and L-shaped, U-shaped, and rectangular networks, it revealed that the more shelterbelts oriented perpendicular to the incoming wind speed, the more pronounced the wind speed attenuation behind the canopy, a longer distance would be required for airflow to recover to the incoming wind speed. In contrast, the wind protection effect of shelterbelts paralleled to the wind direction was extremely limited, making the U-shaped and rectangular networks more effective in wind protection than single shelterbelts and L-shaped networks. The findings would provide references for the structural configuration and optimal layout of shelterbelt systems.


Sujet(s)
Simulation numérique , Forêts , Vent , Modèles théoriques , Conservation des ressources naturelles , Pinus/croissance et développement , Écosystème , Arbres/croissance et développement , Chine
7.
J Exp Biol ; 227(15)2024 Aug 01.
Article de Anglais | MEDLINE | ID: mdl-39111742

RÉSUMÉ

Wind-hovering birds exhibit remarkable steadiness in flight, achieved through the morphing of their wings and tail. We analysed the kinematics of two nankeen kestrels (Falco cenchroides) engaged in steady wind-hovering flights in a smooth flow wind tunnel. Motion-tracking cameras were used to capture the movements of the birds as they maintained their position. The motion of the birds' head and body, and the morphing motions of their wings and tail were tracked and analysed using correlation methods. The results revealed that wing sweep, representing the flexion/extension movement of the wing, played a significant role in wing motion. Additionally, correlations between different independent degrees of freedom (DoF), including wing and tail coupling, were observed. These kinematic couplings indicate balancing of forces and moments necessary for steady wind hovering. Variation in flight behaviour between the two birds highlighted the redundancy of DoF and the versatility of wing morphing in achieving control. This study provides insights into fixed-wing craft flight control from the avian world and may inspire novel flight control strategies for future fixed-wing aircraft.


Sujet(s)
Falconiformes , Vol animal , Queue , Ailes d'animaux , Animaux , Vol animal/physiologie , Ailes d'animaux/physiologie , Ailes d'animaux/anatomie et histologie , Phénomènes biomécaniques , Queue/physiologie , Queue/anatomie et histologie , Falconiformes/physiologie , Falconiformes/anatomie et histologie , Vent
8.
Mar Pollut Bull ; 206: 116802, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39096868

RÉSUMÉ

Based on a search of publications in the scientific literature as well as international reports available online, I draw up a list of 25 documents which include cross-references to the terms offshore wind farms (OFW), and non-indigenous species (NIS). This review shows that no relationship has yet been clearly established between the implementation of OFWs and the colonization of NIS on turbine foundations and scour protections. Evidence for such an effect needs to be documented and confirmed in the future.


Sujet(s)
Espèce introduite , Invertébrés , Vent , Animaux , Conservation des ressources naturelles , Biodiversité
10.
PLoS One ; 19(8): e0305873, 2024.
Article de Anglais | MEDLINE | ID: mdl-39213336

RÉSUMÉ

The unique Tropical cyclone (TC) Fantala appeared in the central Indian Ocean (12.4°S, 73.5°E) at 00Z on April 11 in 2016 and moved northwestward along the northeast of Madagascar at 18 Z on April 15. Then, two incomprehensible turnbacks formed a unique TC track. The dynamic mechanisms of the three turnbacks were first studied based on remote sensing and multisource reanalysis data. The results reveal that the wind field with upper divergence and lower convergence promotes the development of Fantala. The anticyclone high pressure on the middle level atmosphere is an important factor for TC turnbacks. On 15 April, the TC made the first turnback to turn northwest due to the southward anticyclone weakened to moving northwest. On 18 April, the TC made the second turnback along the anticyclone edge due to the northern high-pressure and southern low-pressure trough. On 22 April, the TC made the third turnback because the anticyclonic high press center broke into two small independent anticyclonic centers in the southwest and northeast, which created a barrier band and pushed the northern TC to move to the northwest. Meanwhile, the vertical wind shear (VWS) also provides favorable conditions for TC turnbacks. On April 18, the middle atmosphere of the TC was affected by strong easterly shear and weak southerly shear, and the second turnback was completed. On April 22, the middle level environment was affected by strong westerly shear and weak north shear, and the third turnback was completed. Additionally, heat transport from the ocean to the atmosphere provides favorable conditions for TC development. On April 18, The maximum mean latent heat flux over northeastern Madagascar was 112.94 W/m2, Tropical Cyclone Heat Potential was 39.05 kJ/cm2, and the maximum wind speed at the center of the TC was 155 kts. On April 22, The heat transfer from the equator increased by 18.08 W/m2 compared with the latent heat on 21 April, the Tropical Cyclone Heat Potential was 33.30 kJ/cm2, the maximum wind speed in the TC center was 90 kts, the high PV centerspread down from 850 mb to 900 mb. This study deepens the understanding of track forecasting during the development of a TC.


Sujet(s)
Tempêtes cycloniques , Vent , Madagascar , Océan Indien , Atmosphère
11.
Environ Sci Pollut Res Int ; 31(39): 51774-51789, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-39122971

RÉSUMÉ

In recent years, the concentrations of ozone and the pollution days with ozone as the primary pollutant have been increasing year by year. The sources of regional ozone mainly depend on local photochemical formation and transboundary transport. The latter is influenced by different weather circulations. How to effectively reduce the inter-regional emission to control ozone pollution under different atmospheric circulation is rarely reported. In this study, we classify the atmospheric circulation of ozone pollution days from 2014 to 2019 over Central China based on the Lamb-Jenkinson method and the global analysis data of the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA5) operation. The effectiveness of emission control to alleviate ozone pollution under different atmospheric circulation is simulated by the WRF-Chem model. Among the 26 types of circulation patterns, 9 types of pollution days account for 79.5% of the total pollution days and further classified into 5 types. The local types (A and C type) are characterized by low surface wind speed and stable weather conditions over Central China due to a high-pressure system or a southwest vortex low-pressure system, blocking the diffusion of pollutants. Sensitivity simulations of A-type show that this heavy pollution process is mainly contributed by local emission sources. Removing the anthropogenic emission of pollutants over Central China would reduce the ozone concentration by 39.1%. The other three circulation patterns show pollution of transport characteristics affected by easterly, northerly, or southerly winds (N-EC, EC, S-EC-type). Under the EC-type, removing anthropogenic pollutants of East China would reduce the ozone concentration by 22.7% in Central China.


Sujet(s)
Polluants atmosphériques , Surveillance de l'environnement , Ozone , Polluants atmosphériques/analyse , Chine , Pollution de l'air/prévention et contrôle , Temps (météorologie) , Vent
12.
Waste Manag ; 187: 179-187, 2024 Oct 01.
Article de Anglais | MEDLINE | ID: mdl-39038429

RÉSUMÉ

The recycling of end-of-life wind turbine blades has become a global environmental challenge driven by the rapid growth of wind power. Pyrolysis is a promising method for recovering glass fibers from these discarded blades, but traditional pyrolysis is often operated at high temperatures, which degrades the mechanical properties of recovered fibers. To address this issue, a swelling-assisted pyrolysis method was proposed to recover high-quality glass fibers from end-of-life wind turbine blades at low temperatures. The results confirmed that the decomposition of the resin matrix within the blade was significantly promoted at low temperatures in the swelling-assisted pyrolysis process, achieving a resin decomposition ratio of 76.8 % at 350 °C. This improvement was attributed to enhanced heat transfer and co-pyrolysis with acetic acid. Swelling could physically disrupt the cross-linked structure of the blade, creating a more porous and layered structure, thereby enhancing heat transfer during the pyrolysis process. Simultaneously, the co-pyrolysis with acetic acid could generate hydrogen radicals, which promoted the cracking of macromolecular oligomers into lighter products or gaseous alkanes. Consequently, the formation of pyrolysis char within the solid pyrolysis product was reduced, shortening the oxidation duration to 30 min. In comparison to traditional pyrolysis, the swelling-assisted pyrolysis process effectively suppressed the diffusion of surface defects over the recovered fibers, leading to promising improvements in their flexibility, elasticity, and mechanical properties, with tensile strength notably increased by 27.5 %. These findings provided valuable insights into recovering high-quality glass fibers from end-of-life wind turbine blades.


Sujet(s)
Verre , Pyrolyse , Recyclage , Verre/composition chimique , Recyclage/méthodes , Vent , Température élevée , Centrales énergétiques
13.
An Acad Bras Cienc ; 96(suppl 2): e20230752, 2024.
Article de Anglais | MEDLINE | ID: mdl-39046074

RÉSUMÉ

This study presents geophysical data from two passive seismic measurements conducted at two different sites in Antarctica. We analyzed the signals mainly in the frequency domain through the multitaper method to extract some spectral characteristics of the signals that would have been out of reach through the usual FFT approach. The power spectral density of the signals carries information about the processes that generated them, allowing its correlation with their source origin and type, either natural or anthropogenic. We deal with three different source types: calving, wind, and anthropogenic origins. The former is closely related to glacier dynamics, being modulated by the prevailing atmospheric processes. At both locations the wind noise is prevalent, complicating the analysis of other events like calving. We have used data classification, estimation of the source azimuth, and seismic apparent velocity to demonstrate the viability of using geophysical methods to study glacier elastic parameters and dynamics. Moreover, the calving rate can yield a wider and more independent understanding of glacier hydrodynamics and may help to estimate the future response of the polar areas to a changing environment.


Sujet(s)
Couche de glace , Régions antarctiques , Vent , Surveillance de l'environnement/méthodes
14.
PLoS One ; 19(7): e0305758, 2024.
Article de Anglais | MEDLINE | ID: mdl-39052553

RÉSUMÉ

Wind erosion resulting from soil degradation is a significant problem in Iran's Baluchistan region. This study evaluated the accuracy of remote sensing models in assessing degradation severity through field studies. Sentinel-2 Multispectral Imager's (MSI) Level-1C satellite data was used to map Rutak's degradation severity in Saravan. The relationship between surface albedo and spectral indices (NDVI, SAVI, MSAVI, BSI, TGSI) was assessed. Linear regression establishes correlations between the albedo and each index, producing a degradation severity map categorized into five classes based on albedo and spectral indices. Accuracy was tested with 100 ground control points and field observations. The Mann-Whitney U-Test compares remote sensing models with field data. Results showed no significant difference (P > 0.05) between NDVI, SAVI, and MSAVI models with field data, while BSI and TGSI models exhibited significant differences (P ≤ 0.001). The best model, BSI-NDVI, achieves a regression coefficient of 0.86. This study demonstrates the advantage of remote sensing technology for mapping and monitoring degraded areas, providing valuable insights into land degradation assessment in Baluchistan. By accurately identifying severity levels, informed interventions can be implemented to mitigate wind erosion and combat soil degradation in the region.


Sujet(s)
Technologie de télédétection , Iran , Technologie de télédétection/méthodes , Surveillance de l'environnement/méthodes , Sol/composition chimique , Imagerie satellitaire/méthodes , Érosion du sol , Vent , Conservation des ressources naturelles/méthodes
15.
PLoS One ; 19(7): e0307641, 2024.
Article de Anglais | MEDLINE | ID: mdl-39052597

RÉSUMÉ

Investments in renewable energy sources are increasing in several countries, especially in wind energy, as a response to global climate change caused by the burning of fossil fuels for electricity generation. Thus, it is important to evaluate the Regional Climate Models that simulate wind speed and wind power density in promising areas for this type of energy generation with the least uncertainty in recent past, which is essential for the implementation of wind farms. Therefore, this research aims to calculate the wind power density from Regional Climate Models in areas at Northeast of Brazil from 1986 to 2005. Initially, the ECMWF-ERA5 reanalysis data was validated against observed data obtained from Xavier. The results were satisfactory, showing a strong correlation in areas of Ceará and Rio Grande do Norte (except during the SON season), and some differences in relation to the wind intensity registered by observed data, particularly during the JJA season. Then, the Regional Climate Models RegCM4.7, RCA4 and Remo2009 were validated against the ECMWF-ERA5 reanalysis data, with all models successfully representing the wind speed pattern, especially from December to May. Four specific areas in Northeast of Brazil were selected for further study. In these areas, the RCMs simulations were evaluated to identify the RCM with the best statistical indices and consequently the lowest associated uncertainty for each area. The selected RCMs were: RegCM4.7_HadGEM2 (northern coastal of Ceará and northern coastal of Rio Grande do Norte) and RCA4_Miroc (Borborema and Central Bahia). Finally, the wind power density was calculated from the selected RCM for each area. The northern regions of Rio Grande do Norte and Ceará exhibited the highest wind power density.


Sujet(s)
Vent , Brésil , Modèles climatiques , Énergie renouvelable , Changement climatique , Saisons
16.
J Environ Manage ; 366: 121735, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38972189

RÉSUMÉ

By 2050, approximately 43 million tons of wind-turbine blade (WTB) waste materials will have accumulated, emphasizing the critical importance of effective waste management strategies for WTBs at the end of their life cycle to ensure sustainability. Comparing current WTB waste management methods, reuse emerges as a highly-sustainable method that can also serve as a sustainable solution to environmental challenges, including global warming and natural resource depletion associated with civil engineering activities. This paper presents a comprehensive review of sustainable solutions for reusing WTB waste materials in civil engineering applications. Repurposing WTB waste materials as structural elements in housing, urban furniture, recreational facilities, and slow-traffic infrastructure can be a viable option. WTB waste can also be utilized in powder, fiber, and aggregate forms as an eco-friendly material for construction and pavement (e.g., mortar, concrete, asphalt) to replace cement and natural resource aggregates while meeting necessary strength and performance standards. Through a detailed analysis of reusing WTB waste materials, economic and environmental challenges are also discussed. According to the findings, the properties of mortar, concrete, and asphalt can be affected by the type, shape, and content of fibers, polymers, and impurities present in the blades, as well as the cutting direction. Furthermore, while reuse is considered a sustainable end-of-life (EoL) option for WTB waste management from both economic and environmental perspectives, further research is required to fully understand the environmental consequences of this method.


Sujet(s)
Matériaux de construction , Gestion des déchets , Gestion des déchets/méthodes , Vent , Recyclage , Conservation des ressources naturelles
17.
J Environ Manage ; 366: 121587, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38981272

RÉSUMÉ

Nutrient loads in lakes are spatially heterogeneous, but current spatial analysis method are mainly zonal, making them subjective and uncertain. This study proposes a high-resolution model for assessing spatial differences in nutrient loads based on the lattice Boltzmann method. The model was applied to Dongping Lake in China. Firstly, the contribution rates of four influencing factors, including water transfer, inflow, wind, and internal load, were calculated at different locations in the lake. Then, their proportionate contributions during different intervals to the whole lake area were calculated. Finally, the cumulative load could be calculated for any location within the lake. The validation showed that the model simulated hydrodynamics and water quality well, with relative errors between the simulated and measured water quality data smaller than 0.45. Wind increased the nutrient loads in most parts of the lake. The loads tended to accumulate in the east central area where high-frequency circulation patterns were present. Overall, the proposed water quality model based on the lattice Boltzmann method was able to simulate seven indexes. Therefore, this model represents a useful tool for thoroughly assessing nutrient load distributions in large shallow lakes and could help refine lake restoration management.


Sujet(s)
Lacs , Qualité de l'eau , Chine , Nutriments/analyse , Modèles théoriques , Surveillance de l'environnement/méthodes , Hydrodynamique , Vent
18.
J Environ Manage ; 366: 121659, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38991344

RÉSUMÉ

Mountain forests play an essential role in protecting people and infrastructure from natural hazards. However, forests are currently experiencing an increasing rate of natural disturbances (including windthrows, bark beetle outbreaks and forest fires) that may jeopardize their capacity to provide this ecosystem service in the future. Here, we mapped the risk to forests' protective service across the European Alps by integrating the risk components of hazard (in this case, the probability of a disturbance occurring), exposure (the proportion of forests that protect people or infrastructure), and vulnerability (the probability that the forests lose their protective structure after a disturbance). We combined satellite-based data on forest disturbances from 1986 to 2020 with data on key forest structural characteristics (cover and height) from spaceborne lidar (GEDI), and used ensemble models to predict disturbance probabilities and post-disturbance forest structure based on topographic and climatic predictors. Wind and bark beetles are dominant natural disturbance agents in the Alps, with a mean annual probability of occurrence of 0.05%, while forest fires were less likely (mean annual probability <0.01%), except in the south-western Alps. After a disturbance, over 40% of forests maintained their protective structure, highlighting the important role of residual living or dead trees. Within 30 years after wind and bark beetle disturbance, 61% of forests were likely to either maintain or recover their protective structure. Vulnerability to fires was higher, with 51% of forest still lacking sufficient protective structure 30 years after fire. Fire vulnerability was especially pronounced at dry sites, which also had a high fire hazard. Combining hazard and vulnerability with the exposure of protective forests we identified 186 Alpine municipalities with a high risk to protective forests due to wind and bark beetles, and 117 with a high fire risk. Mapping the disturbance risk to ecosystem services can help identify priority areas for increasing preparedness and managing forests towards lower susceptibility under an intensifying disturbance regime.


Sujet(s)
Conservation des ressources naturelles , Forêts , Écosystème , Animaux , Incendies , Europe , Arbres , Vent
19.
Sci Total Environ ; 949: 174868, 2024 Nov 01.
Article de Anglais | MEDLINE | ID: mdl-39034006

RÉSUMÉ

Passive Acoustic Monitoring (PAM), which involves using autonomous record units for studying wildlife behaviour and distribution, often requires handling big acoustic datasets collected over extended periods. While these data offer invaluable insights about wildlife, their analysis can present challenges in dealing with geophonic sources. A major issue in the process of detection of target sounds is represented by wind-induced noise. This can lead to false positive detections, i.e., energy peaks due to wind gusts misclassified as biological sounds, or false negative, i.e., the wind noise masks the presence of biological sounds. Acoustic data dominated by wind noise makes the analysis of vocal activity unreliable, thus compromising the detection of target sounds and, subsequently, the interpretation of the results. Our work introduces a straightforward approach for detecting recordings affected by windy events using a pre-trained convolutional neural network. This process facilitates identifying wind-compromised data. We consider this dataset pre-processing crucial for ensuring the reliable use of PAM data. We implemented this preprocessing by leveraging YAMNet, a deep learning model for sound classification tasks. We evaluated YAMNet as-is ability to detect wind-induced noise and tested its performance in a Transfer Learning scenario by using our annotated data from the Stony Point Penguin Colony in South Africa. While the classification of YAMNet as-is achieved a precision of 0.71, and recall of 0.66, those metrics strongly improved after the training on our annotated dataset, reaching a precision of 0.91, and recall of 0.92, corresponding to a relative increment of >28 %. Our study demonstrates the promising application of YAMNet in the bioacoustics and ecoacoustics fields, addressing the need for wind-noise-free acoustic data. We released an open-access code that, combined with the efficiency and peak performance of YAMNet, can be used on standard laptops for a broad user base.


Sujet(s)
Surveillance de l'environnement , , Vent , Surveillance de l'environnement/méthodes , Acoustique , République d'Afrique du Sud , Bruit , Animaux
20.
Environ Geochem Health ; 46(8): 269, 2024 Jul 02.
Article de Anglais | MEDLINE | ID: mdl-38954139

RÉSUMÉ

In the confined space of the underground coal mine, which is dominated by transportation lanes, explosion-proof diesel-powered trackless rubber-wheeled vehicles are becoming the main transportation equipment, and the exhaust gas produced by them is hazardous to the health of workers and pollutes the underground environment. In this experiment, a similar test platform is built to study the effects of wind speed, vehicle speed, and different wind directions on the diffusion characteristics of exhaust gas. In this paper, CO and SO2 are mainly studied. The results show that the diffusion of CO and SO2 gas is similar and the maximum SO2 concentration only accounts for 11.4% of the CO concentration. Exhaust gas is better diluted by increasing the wind speed and vehicle speed, respectively. Downwind is affected by the reverse wind flow and diffuses to the driver's position, which is easy to cause occupational diseases. When the wind is a headwind, the exhaust gases spread upwards and make a circumvention movement, gathering at the top. When the wind speed and vehicle speed are both 0.6 m/s, the CO concentration corresponds to the change trend of the Lorentz function when the wind is downwind and the CO concentration corresponds to the change trend of the BiDoseResp function when the wind is headwind. The study of exhaust gas diffusion characteristics is of great significance for the subsequent purification of the air in the restricted mine space and the protection of the workers' occupational health.


Sujet(s)
Industrie minière charbon , Espaces restreints , Emissions des véhicules , Vent , Emissions des véhicules/analyse , Dioxyde de soufre/analyse , Monoxyde de carbone/analyse , Diffusion , Surveillance de l'environnement/méthodes , Polluants atmosphériques/analyse , Polluants atmosphériques d'origine professionnelle/analyse , Exposition professionnelle/analyse
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