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中国机场周围区域飞机噪声监测一直采用计权等效连续感觉噪声级L_(WECPN)为评价量,标准修订后拟采用昼夜等效声级L_(dn)为评价量,监测方法也相应更改。该文通过理论推导及宁波栎社机场噪声现场监测数据,系统比较了2种机场周围区域飞机噪声监测方法,并分析了监测结果的差异及影响因素。结果表明:L_(WECPN)与L_(dn)在相差10 dB的基础上,差值受到单次飞机噪声值和傍晚飞行次数2个因素影响。单次飞机噪声监测量L_(EPN)和L_(AE)在飞机匀速直线经过时差值约为3.75 dB,实际上受到飞行航迹、飞机运动状态、噪声传播环境、突发噪声干扰等因素影响,此次监测的187次飞机L_(EPN)和L_(AE)的差值范围为2.1~5.5 dB。傍晚飞行次数引起的监测结果差值范围为0~4.8 dB。 相似文献
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机场周围飞机噪声测量的影响因素分析 总被引:1,自引:1,他引:0
简要回顾了机场周围飞机噪声的测量方法、评价指标;针对测量过程中存在的问题,从测量周期、飞行架次分布、机型的代表性、环境背景噪声等几个方面考察了对测量数据的影响,对机场周围飞机噪声测量的影响因素进行了分析;论证了缩短测量周期的可行性,当每天的飞行架次在200架左右时,以3 d取代7 d的做法较为可行;对于飞机噪声测量过程中存在的问题,提出了个人看法和建议。 相似文献
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铁路专用线验收噪声监测方法探讨 总被引:1,自引:0,他引:1
铁路专用线与国铁线路相比,具有流量低、分布不均的特点,《声环境质量标准》(GB3096—2008)中交通干线两侧的铁路不包括铁路专用线,铁路专用线两侧的噪声敏感点应该执行相应功能区噪声标准,与铁路边界的距离无关,以火车通过时最大噪声值与背景值比较,评价对其噪声敏感点的影响。本文通过实测数据对铁路专用线噪声监测方法提出看... 相似文献
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科学识别和获取特高压换流站内主要噪声源特性,在此基础上对换流站噪声影响进行分析预测,用于换流站噪声评价、设计和防护。在复杂声场环境条件下,通过现场录波、噪声与振动同步测试等方法,结合噪声理论知识,识别出换流变压器的优势谱点为400 Hz,该点占整个频谱噪声贡献值90%以上,同时识别出交流滤波器场电抗器特征频率点与电抗器所滤除的谐波频率相一致,且换流变压器和交流滤波器场电抗器的声压与振动优势频点具有较强的相关性。根据噪声源特性,对其计算模型进行相应的改进,可提高换流站噪声预测结果的准确性。 相似文献
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简述了机场噪声监控系统,分析了机场噪声监控系统在噪声管理上的作用,指出了国内机场噪声监控系统存在的问题,机场噪声管理水平落后,相关法律规范不够完善,机场噪声监控系统的应用处于探索阶段,机场噪声监控设备的软件功能有待加强。提出,应加快噪声监控系统相关的技术标准体系建设,对国内相关企业加强资金投入,扶持自主技术的研发,推行试点研究,示范项目学习,注重自主研发,推进公众参与度,提升服务功能。 相似文献
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通过龙门山区域的德阳市6个县市农用地土壤中镉的采样监测,分析了该区域镉的分布特征及区域分异原因,并对其环境生态风险进行了评价。结果表明,德阳市农用地土壤中镉含量总体水平为0.11~4.68 mg/kg,呈现西北到东南逐渐降低的分布特征;西北部绵竹和什邡市农用地土壤中镉出现超标的范围较广,2个城市约62.5%的监测点土壤中镉出现超标,且绵竹市农用地土壤中镉超标程度和生态风险程度最重,绵竹地区约25%的监测点土壤中镉出现了轻中度超标;监测区域土壤中镉出现较重生态风险点共有4个,均出现在绵竹;但较高含量的镉在该区域并非大范围连片存在;区域农用地土壤中镉异常的来源主要为龙门山中段的地质背景和部分以矿石为原料企业的综合影响。 相似文献
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Kalikhman I 《Environmental monitoring and assessment》2005,110(1-3):203-215
A mathematical model was used to compare the effects of a regular (one-pass) or interleaved (two-pass) acoustic survey on
the adequacy of reconstructing patchy distribution fields. The model simulates fish or plankton patches of different shapes
and spatial orientations, and a set of parallel or zigzag transects forming a regular or interleaved acoustic survey. The
efficiency of a survey is determined by the adequacy of a reconstructed field to that originally generated, which is evaluated
by calculating their correlations. Regarding the immovable fields, the efficiency of a regular or interleaved acoustic survey
was tested with the following two alternative assumptions: (1) the entire survey was completed; (2) the survey was interrupted
for some reason at the moment when one transect remained non-accomplished. In the former case, the efficiencies of both acoustic
surveys were nearly the same; in the latter case, the efficiency of an interleaved survey was superior to that of a regular
one. With respect to movable fields, the efficiency of the completed interleaved surveys was even higher than that of the
regular ones. Thus, the results obtained allow us to conclude that an interleaved survey is expedient in cases where there
is no preference regarding the position of a vessel for further work. 相似文献
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Topsoil and Housedust Metal Concentrations in the Vicinity of a Lead Battery Manufacturing Plant 总被引:2,自引:0,他引:2
John S. Rieuwerts Margaret Farago Vladimir Bencko 《Environmental monitoring and assessment》1999,59(1):1-13
The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g>
-1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees. 相似文献
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The process of a bioindication of genotoxic effects of complex mixtures on the environment using higher plants is very appropriate and effective. We present the results of an in situ indication of the genotoxic effects of polluted environment near Žilina city. For a more complex monitoring we used: the Tradescantia micronucleus (Trad-MCN) assay, the Tradescantia microspore test and an evaluation of the abortivity of the pollen grains of native plant species. We found significant differences in the frequency of the micronuclei when using the Trad-MCN test in local of Dubeň. The Tradescantia pollen abortivity test showed significant differences in the frequency of the abortive pollen grains between the exposed groups and the control group. By using native plant species in the pollen abortivity test we found significant differences in both of the two locations for the four following species during two consecutive years: Artemisia vulgaris, Melilotus albus, Trifolium pratense, Typha latifolia. 相似文献
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重庆市菜地土壤和蔬菜中Hg、Pb的污染特征及相关性分析 总被引:6,自引:0,他引:6
通过对重庆市菜地土壤和蔬菜 Hg、Pb的含量分析 ,发现土壤 Hg含量远远大于背景值 ,并且土壤 Hg的含量与菜地周围的环境密切相关 ;土壤 Pb的含量同背景值相差不大。Hg、Pb在土壤和蔬菜中的污染特征表现为主城区 >近郊区 >远郊区 ;并且不同蔬菜品种中 Hg、Pb的含量差异较大 ,在不同蔬菜种类表现为叶菜类 >果菜类 >根菜类。相关性分析表明同一菜地土壤和蔬菜中 Hg、Pb含量无相关性 ;不同菜地土壤和蔬菜 Hg、Pb含量不具有相关性。 相似文献
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The concept of a sampling scale triplet of spacing, extent and support is used to define the spatial dimensions of a monitoring network or a field study. The spacing is the average distance between samples, the extent is the size of the domain sampled and the support is the averaging area of one sample. The aim of this paper is to examine what is the bias and the random error (uncertainty) introduced by the sampling scale triplet into estimates of the mean, the spatial variance and the integral scale of a variable in a landscape. The integral scale is a measure of the average distance over which a variable is correlated in space. A large number of two dimensional random fields are generated from which hypothetical samples, conforming to a certain sampling scale triplet, are drawn which in turn are used to estimate the sample mean, spatial variance and integral scale. The results indicate that the biases can be up to two orders of magnitude. The bias of the integral scale is positively related to the magnitude of any of the components of the scale triplet while the bias of the spatial variance is different for different components of the scale triplet. All sampling scale effects are relative to the underlying correlation length of the variable of interest which is closely related to the integral scale. The integral scale can hence be used for sampling design and data interpretation. Suggestions are given on how to adjust a monitoring network to the scales of the variables of interest and how to interpret sampling scale effects in environmental data. 相似文献
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Environment Canada and the Québec Department of the Environment, partners in the St Lawrence Vision 2000 Action Plan, set out to prepare a compendium of knowledge of the flora and fauna of the St Lawrence and to identify potential conservation sites. The resulting Portrait is an Internet site that presents the current knowledge base of the river's ecological and biological diversity (http://lavoieverte.qc.ec.gc.ca/faune/biodiv/index.html). The Portrait provides information on over 5,000 species of flora and fauna. On the website, you will find a detailed ecological analysis of the richness, rarity and vulnerability of several broad groups of plant and animal species. Furthermore, you will find a list of species for each of the 700 survey units and a distribution map for 2,500 species recorded along the St Lawrence., in atlas form, along with a detailed conservation plan. The plan encompasses the most unique and heterogeneous landscapes of the St Lawrence, some of which have no protection at present. The Portrait provides an overview of the sites that are currently protected by public agencies and private-sector organisations and identifies new sites of interest for conserving biodiversity and protecting species at risk. This paper exposes the content of this extensive compendium on the biodiversity of the St. Lawrence. For conciseness, it presents some of the analyses conducted on birds to illustrate a few of the analytical approaches that were used. Then, the information on species richness and concentration areas for priority species of vascular plants, breeding birds and herpetofauna will serve to identify the terrestrial sites of significance for biodiversity. Finally, a similar approach having been applied to the aquatic environnement, we will conclude with a conservation plan that identifies the terrestrial and aquatic ecosystems, and the geographic sites where the most important elements of St. Lawrence biodiversity are concentrated. Our analysis of the biodiversity of the most thoroughly studied taxa of the St. Lawrence clearly shows the importance of wetlands, particularly those located at the mouths of rivers or within archipelagos or delta complexes, such as the groups of islands and channels found at both ends of the Montréal Archipelago. These aquatic landscapes are sites of intense biological production, combining in a small geographical area spawning, nursery and feeding grounds for a large number of fish species and breeding, rearing and foraging areas for aquatic birds. Variable flooding conditions, associated with seasonal flooding or daily tidal fluctuations, create a complex mosaic of wetland and aquatic habitats. Although wetlands occupy only a small area in comparison with terrestrial habitats, they support a large number of rare plant and animal species in relation to their size. At present, 10% of the vascular flora and 27% of the herpetofauna of the St. Lawrence are at risk. In the case of reptiles and amphibians, the situation is especially worrisome because nearly all of the most threatened species live in a narrow band along the river corridor. Not only is this the sector that is under the greatest pressure from human development, very little public land remains here, making it difficult to create protected areas. Increased participation by non-governmental organisations and individuals, through private stewardship arrangements, is an essential precondition for completing the network of conservation areas in this part of the St. Lawrence. Along the estuary and the Gulf, habitat integrity has not been affected as much by the expansion of Québec's human population. This is a vast territory, and sites have been identified with a view to making up for the deficiencies in the present network of protected sites in terms of representing biodiversity. 相似文献