spatial and temporal distribution

时空分布
  • 文章类型: English Abstract
    评价京津冀地区大气臭氧(O3)的时空分布特征,利用土地利用回归(LUR)模型和随机森林(RF)模型对2015年至2020年环境O3浓度进行了模拟。同时,所有原因,心血管,还估计了呼吸死亡率以及归因于O3的经济损失。结果表明,环境O3浓度呈波动上升趋势,死亡率,以及2015年至2020年BTH地区O3暴露造成的经济损失。O3浓度高,变化大的地区集中在中部和西南地区,而北部地区的浓度较低,变化程度很小。死亡率的空间分布也与O3浓度的空间分布一致。从2015年到2020年,BTH地区13个城市的全因死亡率和心血管死亡率的经济损失增加,而BTH地区4个城市的呼吸死亡率经济损失下降。结果表明,O3控制的优先区域不均匀。具体来说,北京,天津,衡水,邢台是BTH地区控制O3污染的重要地区。应根据这些目标地区的特点采取不同的控制措施,以降低O3浓度,减少与O3接触相关的健康影响和经济损失。
    To evaluate the spatial and temporal distribution characteristics of ambient ozone (O3) in the Beijing-Tianjin-Hebei (BTH) Region, the land use regression (LUR) model and random forest (RF) model were used to simulate the ambient O3 concentration from 2015 to 2020. Meanwhile, all-cause, cardiovascular, and respiratory mortalities as well as economic losses attributed to O3 were also estimated. The results showed that upward trends with fluctuation were observed for ambient O3 concentration, mortalities, and economic losses attributable to O3 exposure in the BTH Region from 2015 to 2020. The areas with high O3 concentration and great changes were concentrated in the central and southwestern regions, whereas the concentration in the northern region was low, and the change degree was small. The spatial distribution of the mortalities was also consistent with the spatial distribution of O3 concentration. From 2015 to 2020, the economic losses regarding all-cause mortality and cardiovascular mortality increased in 13 cities of the BTH Region, whereas the economic losses of respiratory mortality decreased in 4 cities in the BTH Region. The results indicated that the priority areas for O3 control were not uniform. Specifically, Beijing, Tianjin, Hengshui, and Xingtai were vital areas for O3 pollution control in the BTH Region. Differentiated control measures should be adopted based on the characteristics of these target areas to decline O3 concentration and reduce health impacts and economic losses associated with O3 exposure.
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  • 文章类型: English Abstract
    Under the background of climate change, extreme wind events occur frequently in Northeast China, and the soil erosion caused by these extreme wind events has attracted progressively more attention from scholars. We used the methods of linear analysis, Sen+Mann-Kendal trend analysis, and Kriging interpolation to analyze the spatial and temporal characteristics of extreme wind in Northeast China from 2005 to 2020, and used the RWEQ wind erosion estimation model to calculate the annual soil wind erosion of typical wind erosion sites and wind erosion under extreme wind conditions. The results showed that the extreme wind frequency in Northeast China presented a significant upward trend from 2005 to 2020, with an increase of 2.9 times·a-1. The annual average extreme wind frequency in Northeast China ranged from 1 to 49 times·a-1, and the high frequency areas were distributed in the northwest of Xilin Gol, the west of the Hulunbuir Plateau, and the northeast of Changbai Mountain. The average contribution rate of extreme wind to soil wind erosion in four typical sites (Xilinhot, New Barhu Right Banner, Nenjiang, and Tongyu) was 31%.
    气候变化背景下东北地区极端大风事件频发,由极端风蚀事件造成的水土流失逐渐引起了相关学者的广泛关注。本研究使用线性分析、Sen+Mann-Kendal趋势分析、Kriging插值法对2005—2020年东北地区极端大风时空特征进行分析,并使用RWEQ风蚀估算模型计算典型风蚀站点的全年土壤风蚀量和极端大风条件下的风蚀量。结果表明: 2005—2020年间,东北地区极端大风频次呈显著上升趋势,上升幅度为2.9次·a-1。东北地区极端大风频次的年均值在1~49次·a-1,频次高值区分布在锡林郭勒西北部、呼伦贝尔高原西部及长白山东北部等地。4个典型风蚀点(锡林浩特、新巴尔虎右旗、嫩江、通榆)极端大风对土壤风蚀量的平均贡献率为31%。.
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  • 文章类型: English Abstract
    以位于黄河中下游的某城区黄河水为研究对象,调查了可培养细菌总数、典型耐药菌(阿莫西林耐药菌和磺胺甲恶唑耐药菌)及其对应的典型耐药基因[β-内酰胺耐药基因(blaCTX-M)和氨基磺胺耐药基因(sulI和Ⅱ)的季节和沿途分布。结果表明,黄河流域可培养菌总数、β-内酰胺耐药菌和磺胺类耐药菌受温度和人类活动影响显著。其属的组成和数量具有明显的时空分布特征,其中芽孢杆菌属和假单胞菌属的组成和数量占优势。抗性基因的丰度随温度的降低而降低。β-内酰胺抗性基因在总基因中的比例高于磺胺基因,磺胺是磺胺基因中的显性基因。相关分析表明,Ⅰ类整合子在促进抗性基因的传播中起着重要作用。本研究深入了解了黄河水质抗性污染现状,为黄河流域中下游抗性基因的风险评估提供了理论支持。
    The Yellow River water of an urban area located in the middle and lower reaches of the Yellow River was taken as the research object, in which the seasonal and along-range distribution of total culturable bacteria, typical antibiotic resistant bacteria (amoxicillin resistant bacteria and sulfamethoxazole-resistant bacteria), and their corresponding typical resistance genes [β-lactam resistance gene (blaCTX-M) and sulfamamide resistance genes (sulI and sulⅡ), as well as intⅠ1 were investigated. The results showed that the total culturable bacteria, β-lactam-resistant bacteria and sulfonamide-resistant bacteria in the Yellow River Basin were significantly affected by temperature and human activities. The composition and quantity of their genera had obvious spatiotemporal distribution characteristics, in which Bacillus and Pseudomonas were dominant in the composition and number of bacteria. The abundance of resistance genes decreased with the decrease in temperature. The proportion of β-lactam resistance genes in the total genes was higher than that of sulfanilamide genes, and sulI was the dominant gene in sulfanilamide genes. Correlation analysis showed that class Ⅰ integron played an important role in accelerating the spread of resistance genes. This study offers insight into the status quo of water resistance pollution in the Yellow River and provides theoretical support for the risk assessment of resistance genes in the middle and lower reaches of the Yellow River Basin.
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  • 文章类型: English Abstract
    The concentrations, spatial-temporal distribution, and influencing factors of 16 polycyclic aromatic hydrocarbons (PAHs) in the sediments of Poyang Lake were studied, and a quantitative source analysis of PAHs in different areas of the lake was conducted. PAHs were widespread within the sediments. The concentrations of ∑16PAHs in the surface sediments of all sites ranged from 203 to 2 318 μg·kg-1. The concentrations of PAHs in the surface sediments of the lake body were higher than those in the surface sediments of the inlet rivers. The ratio of PAHs in Poyang Lake was 4 rings > 5 rings > 6 rings > 3 rings > 2 rings; the composition of 4-ring PAHs was dominant, and its content accounted for 86.11% of ∑16PAHs. The 2- and 3-ring and some 4-ring PAHs, including Flua and Pyr, were more susceptible to SOM, and the 4 through 6-ring PAHs were more susceptible to ORP and heavy metals and other environmental factors. Spatially, the higher concentration of ∑16PAHs occurred in the area of the lake adjacent to Duchang County and Poyang County, where the terrain was relatively closed, and the water exchange with the surrounding area was less than that in other sections, which was not conducive to the migration, transformation, and degradation of pollutants. In the temporal distribution, the changes in PAHs concentration level and the development of GDP in Jiangxi Province showed high consistency, and the influence of economic development and human activities might have been the main reason for the increasing PAHs concentration level. The main sources of PAHs in surface sediments of Poyang Lake included petroleum pollution and oil and coal and biomass combustion sources, and there were some spatial differences in PAHs sources in different regions. This study can provide a reference for PAHs pollution in surface sediments of Poyang Lake, which is important for the ecological environmental protection and management of Poyang Lake.
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  • 文章类型: English Abstract
    为了解长寿湖水污染现状及环境风险,重金属的浓度(Cr,Cu,Zn,As,Cd,在不同季节收集和分析了水中的Pb)。这项研究调查了时空变化,分布特征,污染水平,长寿湖重金属的健康风险。结果表明,6种重金属均低于《地表水环境质量标准》(GB3838-2002)Ⅰ类标准,但是近年来出现了增长趋势,与铜,As,Pb呈显著增加(P<0.05)。这些重金属的时空分布不同。暂时,夏季地表水中Cr和Cd浓度较高,As和Zn在春季较高,铅和铜在秋季和冬季较高。空间上,Cr的浓度,As,Cu,Zn,铅在水库的南部出口显示出更高的浓度,龙溪河西北部进水口,水库的中央部分,而Cd在北部停滞区较高。长寿湖水体重金属总体水平较低,Cr和Cu受到轻微污染,而其他重金属被确定为具有微不足道的污染水平。饮用水是地表水体致癌和非致癌重金属的主要暴露途径。水体中Cr和As的健康风险值很高,范围分别为6.2×10-10至3.0×10-4和5.1×10-8至3.9×10-5。儿童和成人对总健康风险的相应贡献率很高,Cr占87.18%和87.20%,分别,而As占12.73%和12.71%,分别。因此,至关重要的是优先考虑与Cr和Cu相关的环境风险,以及长寿湖与Cr和As相关的健康风险这些发现为长寿湖的水污染控制和环境质量改善提供了科学依据,合理开发利用水资源。
    To understand the water pollution status and environmental risks of Changshou Lake, the concentrations of heavy metals (Cr, Cu, Zn, As, Cd, and Pb) in the water were collected and analyzed during different seasons. The study investigated temporal and spatial variations, distribution characteristics, pollution levels, and health risks associated with heavy metals in Changshou Lake. The results showed that all six heavy metals were below than the Class Ⅰ standard of the Surface Water Environmental Quality Standard (GB 3838-2002), but recent years have witnessed an increasing trend, with Cu, As, and Pb showing a significant increase (P<0.05). The temporal and spatial distributions of these heavy metals were different. Temporally, Cr and Cd concentrations in surface water were higher in summer, As and Zn were higher in spring, and Pb and Cu were higher in autumn and winter. Spatially, the concentrations of Cr, As, Cu, Zn, and Pb showed higher concentrations in the southern outlet of the reservoir, the northwestern Longxi River inlet, and the central part of the reservoir, whereas Cd was higher in the northern stagnant area. The overall levels of heavy metals in the water body of Changshou Lake were low, with Cr and Cu slightly polluted, while other heavy metals were identified as having an insignificant pollution level. Drinking water was the primary exposure pathway to carcinogenic and non-carcinogenic heavy metals in surface water bodies. The health risk values of Cr and As in water bodies were high, ranging from 6.2×10-10 to 3.0×10-4 and 5.1×10-8 to 3.9×10-5, respectively. The corresponding contribution rates for children and adults to the total health risk were high, with Cr accounting for 87.18% and 87.20%, respectively, while As accounted for 12.73% and 12.71%, respectively. Therefore, it is crucial to prioritize environmental risks associated with Cr and Cu, as well as the health risks associated with Cr and As in Changshou Lake These findings provide a scientific foundation for water pollution control and environmental quality improvement in Changshou Lake, and rational development and utilization of water resources.
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  • 文章类型: Journal Article
    生活污水是人类社会不可忽视的主要碳源之一。在碳峰值和碳中和(双碳)目标的背景下,持续的城市化给城市排水系统带来了沉重的压力。然而,排水系统复杂的主客观条件限制了现场监测,测量,和排水系统的分析,成为研究排水系统碳排放的一大障碍。在本文中,3389个物联网(IoT)传感器终端用于构建城市生活污水甲烷(CH4)碳排放的现场监测物联网,以中国重庆市的21个主要地区为研究区。结合菲克的扩散定律,这种现场监测物联网基于测量的浓度推导了甲烷碳排放的测量模型,解决了复杂井下环境中甲烷气体长期稳定监测测量的问题。利用GIS时空分析方法分析排水系统中化粪池碳排放的时空演变规律,它成功地揭示了不同季节排水系统甲烷碳排放的时空分布,以及排水系统的甲烷碳排放与阳光直射纬度之间的关系。应用DTW方法,它量化了排水系统中甲烷监测的稳定性,并评估了采样频率(SF)和设备终端数量(NDT)对甲烷监测稳定性的影响。因此,物联网基础上构建城市生活污水碳排放智能管理系统,整合了甲烷监测,化粪池排水系统的测量和分析。
    Domestic wastewater is one of the major carbon sources that cannot be ignored by human society. Against the background of carbon peaking & carbon neutrality (Double Carbon) goals, the continuous urbanization has put heavy pressure on urban drainage systems. Nevertheless, the complex subjective and objective conditions of drainage systems restrict the field monitoring, measurement, and analysis of drainage systems, which has become a great obstacle to the study of carbon emissions from drainage system. In this paper, 3389 sensor terminals of Internet of Things (IoT) are used to build a field monitoring IoT for urban domestic wastewater methane (CH4) carbon emission, with 21 main districts of Chongqing Municipality in China as the study area. Incorporating Fick\'s law of diffusion, this field monitoring IoT derives a measurement model for methane carbon emissions based on measured concentrations, and solves the problems of long-term and stable monitoring and measurement of methane gas in complex underground environment. With GIS spatio-temporal analysis used to analyze the spatial and temporal evolution patterns of carbon emissions from septic tanks in drainage systems, it successfully reveals the spatial and temporal distribution of methane carbon emissions from drainage systems in different seasons, as well as the relationship between methane carbon emissions from drainage systems and the latitude of direct sunlight. Applying the DTW method, it quantifies the stability of methane monitoring in drainage systems and evaluates the effects of Sampling Frequency (SF) and Number of Devices Terminal (NDT) on the stability of methane monitoring. Consequently, an intelligent management system for carbon emissions from urban domestic wastewater is constructed on the base of IoT, which integrates methane monitoring, measurement and analysis in septic tanks of drainage systems.
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  • 文章类型: Journal Article
    考虑到大气污染物的时空效应,使用地理和时间加权回归和地理智能随机森林(GTWR-GeoiRF)模型和Sentinel-5P卫星遥感数据,结合气象,排放清单,现场观察,人口,高程,和其他数据,估计了2020年3月至2021年2月中国近地面的高精度臭氧浓度及其时空分布。在此基础上,污染状况,近地表臭氧浓度,并对人群暴露风险进行分析。研究结果表明,GTWR-GeoiRF模型的估计结果具有较高的精度,与非混合模型相比,估计结果的精度更高。降尺度方法在一定程度上增强了估计结果,同时解决了某些数据中空间分辨率有限的问题。我国近地表臭氧浓度空间分布具有明显的区域性和季节性特征。东部地区的臭氧浓度最高,东北地区最低,冬季低点高于夏季高点。臭氧人群暴露风险存在显著差异,中国东部地区暴露风险最高,人群暴露风险大多在0.8到5之间。
    Considering the spatial and temporal effects of atmospheric pollutants, using the geographically and temporally weighted regression and geo-intelligent random forest (GTWR-GeoiRF) model and Sentinel-5P satellite remote sensing data, combined with meteorological, emission inventory, site observation, population, elevation, and other data, the high-precision ozone concentration and its spatiotemporal distribution near the ground in China from March 2020 to February 2021 were estimated. On this basis, the pollution status, near-surface ozone concentration, and population exposure risk were analyzed. The findings demonstrate that the estimation outcomes of the GTWR-GeoiRF model have high precision, and the precision of the estimation results is higher compared with that of the non-hybrid model. The downscaling method enhances estimation results to some extent while addressing the issue of limited spatial resolution in some data. China\'s near-surface ozone concentration distribution in space shows obvious regional and seasonal characteristics. The eastern region has the highest ozone concentrations and the lowest in the northeastern region, and the wintertime low is higher than the summertime high. There are significant differences in ozone population exposure risks, with the highest exposure risks being found in China\'s eastern region, with population exposure risks mostly ranging from 0.8 to 5.
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  • 文章类型: Journal Article
    植物-传粉者的相互作用在生态和经济上都很重要,and,因此,他们的预测是生态学家的重要理论和应用目标。尽管有各种分析方法可用,我们预测植物-传粉者相互作用的能力仍然有限。不同植物-传粉者相互作用模型的预测能力取决于用于概念化和量化物种属性的特定定义(例如,形态性状),采样效应(例如,检测概率),以及数据分辨率和可用性。植物-传粉媒介相互作用研究的进展需要有关控制相互作用的机制和物种属性的概念和方法上的进步,以及改进的建模方法来预测相互作用。当前预测植物与传粉媒介相互作用的方法为改进提供了充足的机会,并为基础和应用研究开辟了新的视野。
    Plant-pollinator interactions are ecologically and economically important, and, as a result, their prediction is a crucial theoretical and applied goal for ecologists. Although various analytical methods are available, we still have a limited ability to predict plant-pollinator interactions. The predictive ability of different plant-pollinator interaction models depends on the specific definitions used to conceptualize and quantify species attributes (e.g., morphological traits), sampling effects (e.g., detection probabilities), and data resolution and availability. Progress in the study of plant-pollinator interactions requires conceptual and methodological advances concerning the mechanisms and species attributes governing interactions as well as improved modeling approaches to predict interactions. Current methods to predict plant-pollinator interactions present ample opportunities for improvement and spark new horizons for basic and applied research.
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  • 文章类型: Journal Article
    本研究旨在使用先进的机器学习分类技术了解Derawan岛珊瑚礁栖息地在过去20年(2003年,2011年和2021年)的动态变化。动机源于对准确的迫切需要,详细的环境监测,以告知保护策略,特别是在珊瑚礁等生态敏感地区。我们采用了非参数机器学习算法,包括随机森林(RF),支持向量机(SVM)和分类和回归树(CART),评估珊瑚栖息地的时空变化。我们的分析利用了来自Landsat9,Landsat7,Sentinel-2和多光谱航空照片的高分辨率数据。RF算法被证明是最准确的,Landsat9的准确度为71.43%,Sentinel-2的准确度为73.68%,多光谱航空照片的准确度为78.28%。我们的发现表明,分类精度受到地理分辨率以及野外和卫星/航空图像数据质量的显着影响。二十年来,从2003年到2011年,珊瑚礁面积显着减少,减少到16公顷,其次是面积略有增加,但在2011年至2021年间密度更异质。该研究强调了珊瑚礁栖息地的动态性质以及机器学习在环境监测中的功效。获得的见解强调了先进的分析方法在指导保护工作和了解生态变化方面的重要性。
    This study aims to understand the dynamic changes in the coral reef habitats of Derawan Island over two decades (2003, 2011, and 2021) using advanced machine learning classification techniques. The motivation stems from the urgent need for accurate, detailed environmental monitoring to inform conservation strategies, particularly in ecologically sensitive areas like coral reefs. We employed non-parametric machine learning algorithms, including Random Forest (RF), Support Vector Machine (SVM), and Classification and Regression Tree (CART), to assess spatial and temporal changes in coral habitats. Our analysis utilized high-resolution data from Landsat 9, Landsat 7, Sentinel-2, and Multispectral Aerial Photos. The RF algorithm proved to be the most accurate, achieving an accuracy of 71.43% with Landsat 9, 73.68% with Sentinel-2, and 78.28% with Multispectral Aerial Photos. Our findings indicate that the classification accuracy is significantly influenced by the geographic resolution and the quality of the field and satellite/aerial image data. Over the two decades, there was a notable decrease in the coral reef area from 2003 to 2011, with a reduction to 16 hectares, followed by a slight increase in area but with more heterogeneous densities between 2011 and 2021. The study underscores the dynamic nature of coral reef habitats and the efficacy of machine learning in environmental monitoring. The insights gained highlight the importance of advanced analytical methods in guiding conservation efforts and understanding ecological changes over time.
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  • 文章类型: Journal Article
    Wolbachia和立克次体是细菌内共生体,可以在节肢动物宿主中引起许多生殖异常。我们筛选并建立了烟粉虱中Wolbachia和立克次体的共感染,并比较了卵中Wolbachia和立克次体的时空分布(产卵后3-120小时),若虫,通过qPCR定量和荧光原位杂交(FISH)和成虫烟粉虱。结果表明,3-120h龄鸡蛋中Wolbachia和立克次体的滴度呈“w”型波动,而Wolbachia和立克次体的滴度有一个“下降-上升-上升”的变化过程。立克次体和Wolbachia若虫的滴度以及AsiaII1B.tabaci的成年生命阶段通常随着粉虱的发展而增加。然而,Wolbachia和立克次体在卵中的位置从卵茎变为卵基,然后从鸡蛋底部到鸡蛋后部,最后回到鸡蛋的中间。这些结果将为烟草不同生命阶段中Wolbachia和立克次体的数量和定位提供基本信息。这些发现有助于理解共生细菌的垂直传播动力学。
    Wolbachia and Rickettsia are bacterial endosymbionts that can induce a number of reproductive abnormalities in their arthropod hosts. We screened and established the co-infection of Wolbachia and Rickettsia in Bemisia tabaci and compared the spatial and temporal distribution of Wolbachia and Rickettsia in eggs (3-120 h after spawning), nymphs, and adults of B. tabaci by qPCR quantification and fluorescent in situ hybridization (FISH). The results show that the titer of Wolbachia and Rickettsia in the 3-120 h old eggs showed a \"w\" patterned fluctuation, while the titers of Wolbachia and Rickettsia had a \"descending-ascending descending-ascending\" change process. The titers of Rickettsia and Wolbachia nymphal and the adult life stages of Asia II1 B. tabaci generally increased with the development of whiteflies. However, the location of Wolbachia and Rickettsia in the egg changed from egg stalk to egg base, and then from egg base to egg posterior, and finally back to the middle of the egg. These results will provide basic information on the quantity and localization of Wolbachia and Rickettsia within different life stages of B. tabaci. These findings help to understand the dynamics of the vertical transmission of symbiotic bacteria.
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