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1.
为研究春运期间北京市PM2.5和气态污染物的污染特征,根据35个空气监测子站周边环境类型的不同将北京市划分为城区、郊区、对照区和交通密集区.结合春运期间的人为活动,比较分析各类污染物在各区域的日均浓度变化特征;将PM2.5日均浓度与SO2、NO2、CO、O3日均浓度及北京市的日均温度、相对湿度、风级进行相关性分析.结果显示,春运期间北京市PM2.5污染最严重,超过《环境空气质量标准》二级标准的天数占45%;PM2.5日均浓度变化趋势与春运客流量变化具有较好的一致性;各区域PM2.5、SO2、NO2和CO的日均浓度均符合交通密集区城区郊区对照区的分布,而O3的情况为对照区郊区城区交通密集区;各区域PM2.5浓度分别与该区域SO2、NO2、CO浓度呈正相关,与O3浓度呈负相关;各区域PM2.5浓度与温度未见相关性,与相对湿度呈正相关,与风级呈负相关.本文的研究结果表明,交通运输、烟花燃放和气象因子对春运期间PM2.5的污染特征影响较大.  相似文献   

2.
利用乌鲁木齐2014年3月1日至2015年2月28日PM2.5、PM10、SO2、CO、NO2、O3浓度的日平均数据,结合相应气象要素资料,分析了大气污染物浓度的逐日变化、季节变化特征.建立了基于气体污染物的PM2.5浓度预测模型,探讨了污染物浓度与气象要素的相关性.结果表明:(1)整个1年期间PM2.5、PM10、SO2、NO2、O3年平均浓度分别为67.9、159.3、24.9、56.1、31.5μg·m-3,CO为1.4 mg·m-3.(2)各污染物浓度频率分布不一.期间SO2的污染并未超标,NO2超标率为15.3%,说明"煤改气"能源结构的调整对SO2浓度的降低起到了积极作用,但是由于机动车保有量的增加,使得机动车排放的NO2浓度超过了燃煤.(3)PM2.5与PM10、SO2、CO、NO2、O3具有很强的相关性,尤其与SO2、CO、NO2更为明显,说明机动车尾气和化石燃料的燃烧是乌鲁木齐市PM2.5的重要来源,此外,建立了基于气体污染物的PM2.5浓度预测模型为:CPM2.5=0.21376CPM10+0.42422CSO2+41.66384CCO-0.24325CNO2+0.12466CO3-24.15316.(4)PM2.5、SO2和CO均与气温和水汽压存在较大的负线性相关关系,与O3呈显著的正相关关系.相对湿度与O3浓度的相关性最高为-0.62,与CO有一定的正相关关系,与其他污染物的相关性不大.风速对大气污染的影响较小.日照时数对污染物也有一定影响.  相似文献   

3.
郑煜  邓兰 《生态环境》2014,(12):1953-1957
以往对PM2.5的研究多集中在气象因子或单一空气污染物对PM2.5质量浓度变化的影响,未考虑多种空气污染物对PM2.5质量浓度的协同作用。通过哈尔滨市环保局发布的2014年1月份(共31 d)市区内主要空气污染物SO2、NO2、PM10、CO、O3、PM2.5的质量浓度数据,运用相关性分析、PLS1和通径分析方法,研究哈尔滨市区内主要空气污染物对PM2.5质量浓度变化的直接影响、通过其他空气污染物的间接影响及污染物之间的协同作用。结果表明,SO2、NO2、PM10、CO 与 PM2.5质量浓度显著性相关,O3与 PM2.5质量浓度相关性不显著,SO2、NO2、PM10、CO 之间存在严重的复相关性。依据相关性分析结果,建立了SO2、NO2、PM10、CO对PM2.5质量浓度的PSL1模型,模型的拟合优度r2为0.852,模型拟合良好。对所建立的模型进行通径分析,结果显示,SO2、NO2、PM10、CO对PM2.5质量浓度变化的直接作用分别为0.005、-0.142、-0.140、1.191,CO对PM2.5质量浓度变化的直接影响作用最大。SO2、NO2、PM10通过CO对PM2.5质量浓度变化的间接作用分别为0.706、1.011、1.118均大于它们对PM2.5质量浓度变化的直接作用。SO2、NO2、PM10、CO对PM2.5质量浓度变化的总决定系数为85.9%。CO是主要空气污染物中影响PM2.5质量浓度变化的主要因素,降低冬季煤炭供暖期CO的排放量,有利于提高空气环境质量,降低对人体的健康危害。  相似文献   

4.
以往对PM2.5的研究多集中在气象因子或单一空气污染物对PM2.5质量浓度变化的影响,未考虑多种空气污染物对PM2.5质量浓度的协同作用。通过哈尔滨市环保局发布的2014年1月份(共31 d)市区内主要空气污染物SO2、NO2、PM10、CO、O3、PM2.5的质量浓度数据,运用相关性分析、PLS1和通径分析方法,研究哈尔滨市区内主要空气污染物对PM2.5质量浓度变化的直接影响、通过其他空气污染物的间接影响及污染物之间的协同作用。结果表明,SO2、NO2、PM10、CO与PM2.5质量浓度显著性相关,O3与PM2.5质量浓度相关性不显著,SO2、NO2、PM10、CO之间存在严重的复相关性。依据相关性分析结果,建立了SO2、NO2、PM10、CO对PM2.5质量浓度的PSL1模型,模型的拟合优度r2为0.852,模型拟合良好。对所建立的模型进行通径分析,结果显示,SO2、NO2、PM10、CO对PM2.5质量浓度变化的直接作用分别为0.005、-0.142、-0.140、1.191,CO对PM2.5质量浓度变化的直接影响作用最大。SO2、NO2、PM10通过CO对PM2.5质量浓度变化的间接作用分别为0.706、1.011、1.118均大于它们对PM2.5质量浓度变化的直接作用。SO2、NO2、PM10、CO对PM2.5质量浓度变化的总决定系数为85.9%。CO是主要空气污染物中影响PM2.5质量浓度变化的主要因素,降低冬季煤炭供暖期CO的排放量,有利于提高空气环境质量,降低对人体的健康危害。  相似文献   

5.
北京大气中SO2、NOx、CO和O3体积分数变化分析   总被引:6,自引:0,他引:6  
为了探讨北京市大气污染物的污染水平和变化特征,2004年8月—2005年7月对北京大气中SO2、NOx、O3和CO体积分数进行了连续观测,并对比分析不同季节的变化特征。结果表明,SO2体积分数呈双峰曲线日变化,在08:00和23:00出现峰值。SO2采暖季日振幅明显高于非采暖季日振幅,采暖季SO2体积分数要比非采暖季高出3倍以上。NOx、CO体积分数在早晨07:00和傍晚20:00左右出现峰值,NOx体积分数最大值可达130×10-9,而CO体积分数最大值可达3300×10-9。NO有明显的日变化和季节变化,而NO2白天夜晚都维持在同一水平,且季节变化也不大。O3体积分数夏季远远高于冬季,日变化均呈单峰型分布,午后14:00—15:00出现峰值。  相似文献   

6.
上甸子区域本底站大气痕量活性气体的变化规律   总被引:7,自引:0,他引:7  
利用TE公司C系列气体监测仪,于2005年1月1日-12月31日,在北京上甸子区域大气本底站连续观测SO2,CO,NO-NO2-NOx和O3的浓度.分析了晴天、雨天、霾天和沙尘天气条件下,不同气体的变化特征及影响因素.结果表明:(1)痕量活性气体在不同天气条件下具有不同的浓度及日变化特征,晴天和雨天日变化最小,而霾天日变化最大;(2)风向和风速是影响上甸子气体浓度变化的重要因素,同时,夏季降水对SO2和NOx的去除作用较为明显;(3)上甸子O3白天最大值与夜间最小值的比值低于4,远低于城区,不利于光化学污染的形成.  相似文献   

7.
利用嘉兴2012年10月—2013年9月污染气体和PM2.5的连续观测资料,结合HYSPLIT_4轨迹模式计算得到的观测期间嘉兴不同季节的主导气团,分析了嘉兴市大气污染物的变化特征及不同季节下不同气团类型对该地污染物的影响.结果表明,嘉兴市CO、SO2、NO2和PM2.5日变化为双峰型分布,峰值位于07∶00—09∶00和16∶00—18∶00;O3呈单峰分布,峰值位于14∶00,这与人为活动和大气边界层变化密切相关.大气污染物具有显著的季节变化特征,SO2、CO和PM2.5冬季高(43.5,950.3,79.8μg·m-3),夏季低(21.5、522.4、38.0μg·m-3);NO2在春季最高(49.9μg·m-3),夏季最低(30.4μg·m-3);O3夏季最高(88.9μg·m-3),冬季最低(17.2μg·m-3).影响嘉兴的主导气团的来源和路径存在显著季节变化,不同气团对大气污染物的分布影响较大,局地气团下SO2的浓度显著降低;大陆气团下污染物浓度普遍偏高,SO2、CO、NO2和PM2.5分别是海洋性气团的1.6—3.0、1.5—1.6、1.6—2.0和1.5—2.3倍;海洋性气团下污染物浓度普遍较低;混合性气团对应的污染物水平介于海洋性气团和大陆气团之间.  相似文献   

8.
西安冬、夏季PM2.5中水溶性无机离子的变化特征   总被引:3,自引:0,他引:3  
为探讨西安市冬、夏季水溶性无机离子的季节和空间变化特征,2010年1月和7月分别在西安城区4个站点及上风区高陵(GL)和下风区黑河(HH)连续采集2周的PM2.5样品,使用离子色谱仪分析样品中水溶性无机离子成分.结果表明,PM2.5质量浓度冬季明显高于夏季,空间变化表现为:城区站点浓度均值(172.6μg.m-3)>上风区点GL(98.9μg.m-3)>下风区点HH(81.0μg.m-3).水溶性无机离子浓度总和占PM2.5质量浓度的41.8%,其中SO24-、NO3-和NH4+是水溶性离子的主要成分,分别占总离子质量浓度的35.1%、22.6%和12.2%.Na+、Ca2+和Mg2+在冬、夏季浓度相差不大,而SO24-、NO3-、NH4+以及K+、Cl-等均明显表现为冬季浓度高于夏季.SO24-、NO3-和NH4+在冬、夏季空间变化均表现为城区站点>GL>HH,这3种离子夏季在大气中的主要存在方式为NH4HSO4和NH4NO3,而冬季主要以(NH4)2SO4、NH4NO3和NH4Cl形式存在.NO3-/SO24-的比值为0.64,表明西安市固定源仍是主要污染贡献源,但是移动源所占比例较之前研究有所上升,应采取一定措施控制机动车数量并加强排放监控.  相似文献   

9.
了解北京市城区和郊区大气细颗粒物中的四种水溶性阴离子F-、Cl-、SO42-、NO3-的浓度水平,并分析影响其水平高低的因素。使用聚四氟乙烯滤膜分别采集北京市城区和郊区大气中的PM2.5,用纯水提取后采用离子色谱法测定水溶性阴离子质量浓度。采样期间北京市大气PM2.5、F-、Cl-、SO42-和NO3-质量浓度几何均数分别为55.36、0.02、0.46、6.72和1.09μg·m-3,四种水溶性阴离子质量浓度总和占PM2.5质量浓度的19.14%;同一季节(春季)郊区监测点大气PM2.5、SO42-和NO3-质量浓度显著高于城区监测点;城区大气PM2.5与四种水溶性阴离子质量浓度秋季高于春季,但差异无统计学意义;大气PM2.5与Cl-、SO42-和NO3-质量浓度均高度相关。Cl-、SO42-、NO3-是北京市大气PM2.5的重要组成成分。  相似文献   

10.
了解北京市城区和郊区大气细颗粒物中的四种水溶性阴离子F-、Cl-、SO42-、NO3-的浓度水平,并分析影响其水平高低的因素。使用聚四氟乙烯滤膜分别采集北京市城区和郊区大气中的PM2.5,用纯水提取后采用离子色谱法测定水溶性阴离子质量浓度。采样期间北京市大气PM2.5、F-、Cl-、SO42-和NO3-质量浓度几何均数分别为55.36、0.02、0.46、6.72和1.09μg·m-3,四种水溶性阴离子质量浓度总和占PM2.5质量浓度的19.14%;同一季节(春季)郊区监测点大气PM2.5、SO42-和NO3-质量浓度显著高于城区监测点;城区大气PM2.5与四种水溶性阴离子质量浓度秋季高于春季,但差异无统计学意义;大气PM2.5与Cl-、SO42-和NO3-质量浓度均高度相关。Cl-、SO42-、NO3-是北京市大气PM2.5的重要组成成分。  相似文献   

11.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

12.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

13.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

14.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

15.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

16.
An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.  相似文献   

17.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

18.
How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.  相似文献   

19.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

20.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  相似文献   

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