首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
青岛市主干道沿线高层建筑的交通噪声研究   总被引:2,自引:1,他引:1  
采用A计权网络对青岛市东西快速路沿线高层建筑进行监测。利用Grapher软件,以Leq为监测值的基准值绘制连续线状图,分析城市主干道周边高层建筑上交通噪声的峰值点。根据道路中心线到高层建筑的距离信息,得出高层建筑交通噪声峰值点与道路中心线的连线与水平地面间的角度约为30°。  相似文献   

2.
为研究高架斜坡道路声场分布规律,根据城市快速路设计规范建立相应的斜坡道路模型,通过微观交通仿真软件结合噪声计算插件对其进行噪声动态模拟,获取三维空间的噪声值及道路垂直截面声场分布图,给出高架斜坡道路的声场分布规律。结果表明:高架斜坡道路上下坡两侧声场分布不对称,上坡一侧声影区界限划分较为明显,而下坡一侧声影区界限划分不明显;下坡侧接受点在高度4~20 m时,噪声值大于上坡侧对称点处的噪声值。  相似文献   

3.
为科学全面地开展城市道路交通噪声影响评估,更精确地服务道路交通噪声污染治理工作,选取南京市具有代表性的道路交通干线,采用手工监测和自动连续监测的方法,进行不同路段噪声污染程度及其随时间、空间变化规律的研究。结果表明,地面快速路段、高架路段以及衔接路段两侧噪声敏感建筑物受道路交通噪声影响较大,夜间均超标;相邻区域要达到2类声环境功能区昼间标准限值要求,需距离地面快速路慢车道约45 m,距离高架路段慢车道约92 m;要达到2类声环境功能区夜间标准限值要求,需距离地面快速路慢车道约175 m,距离高架路段慢车道约172 m;敏感建筑物所受噪声影响随楼层高度升高而增大,同时噪声影响情况与道路两侧建筑物密度、道路车辆行驶速度有关。建议严格道路及噪声敏感建筑物规划控制,采取阻断传声路径、受声建筑物强化保护等措施控制噪声影响。  相似文献   

4.
城市快速路是城市交通运输网的重要组成部分,其产生的交通噪声相当严重。评价城市快速路交通噪声对其两侧交通噪声敏感点的污染状况是目前面临的一个难题。文章以深圳市罗湖区罗沙路为例,对其周边的交通噪声敏感点进行现状调查,利用SoundPLAN软件模拟噪声污染状况,并对安装声屏障前后的降噪效果进行评价,为城市快速路交通噪声污染防治措施的制定提供基础数据和建议。  相似文献   

5.
广州市昼夜道路交通噪声的监测与分析   总被引:7,自引:1,他引:6  
对广州市的昼夜交通噪声污染现状进行了分区域分道路等级的实地监测,得到共53个监测点位白天和夜晚的等效声级及其统计声级,同时对每个监测点展开了交通流调查,并分析交通流特征对交通噪声的影响。监测结果表明, 白天快速路、主干路、次干路及支路的平均等效声级分别为74.2、72.2、67.8、65.1 dB,快速路及主干路沿线的交通噪声污染比次干路及支路的严重。夜晚所有测点的噪声值均超过55 dB,快速路、主干路、次干路及支路的平均等效声级分别为72.2、72.3、66.3、64.5 dB,广州市夜晚的交通噪声污染较为严重。  相似文献   

6.
高架复合道路交通噪声时空分布规律研究   总被引:2,自引:0,他引:2  
通过对杭州市典型高架复合道路交通噪声监测,研究高架复合道路交通噪声的时空分布规律。结果表明,噪声与车流量、车辆类型及车速密切相关;噪声随着与高架路距离的增大,地面各测点的噪声值呈递减趋势;高架复合道路平直段与下坡路段的噪声在临街建筑竖直立面的分布规律基本一致,但在不同高度的影响程度上存在一定差异。  相似文献   

7.
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   

8.
采取1/3倍距法布设测点,使用多通道噪声分析系统,对城市轨道交通噪声进行地面和轨面上的水平测试及垂向测试,取得其距离衰减规律、声级垂向分布等特性,新的测试点位布设方案取得了比传统测试方案更详细的测试结果。研究结果对于城市轨道交通噪声特性的研究及其控制方法的确定具有重要的学术意义和工程价值,同时对城市轨道交通噪声的测试方案进行了有益的探索。  相似文献   

9.
南京市快速道路交通噪声污染调查   总被引:2,自引:0,他引:2  
对南京市城西干道凤台路、虎踞北路双层高架道路交通噪声进行了测量.结果表明,城西干道两侧30m范围内夜间噪声严重超标.建议今后在建设城市快速道路时,地面路段两侧可种植绿化隔离带,高架路段设置隔声屏障;不具备条件的可为临街住户安装隔声门窗,以保护道路两侧的居住环境.  相似文献   

10.
北京市典型道路交通噪声排放特征   总被引:1,自引:1,他引:0  
采用北京市道路交通噪声自动监测系统2013—2017年采集的等效连续A声级数据,对城市快速路、城市主干线、城市次干线、城市支路的代表性站点噪声排放情况进行了统计分析,结果显示,北京市不同等级的道路噪声排放具备一定的特征,排放水平从大到小依次为城市快速路城市主干线城市支路和城市次干线,道路噪声随时间变化存在较为一致的周期性排放特征,24 h变化特征比较明显。个别道路排放特征存在特异性,如城市主干线道路的一个代表监测站点噪声监测值出现了逐年下降趋势,分析发现,北京市非首都功能疏解对其噪声值的下降有一定贡献。采取一定的规划和管理措施有助于减少道路交通噪声的排放。  相似文献   

11.
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   

12.
The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.  相似文献   

13.
A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.  相似文献   

14.
The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.  相似文献   

15.
The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.  相似文献   

16.
用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%~107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。  相似文献   

17.
Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes   总被引:6,自引:0,他引:6  
Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.  相似文献   

18.
We determined concentrations of selected trace elements inlivers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadianarctic during 1997 and 1998. Concentrations of totalmercury and organic mercury were generally low in the liversof these birds (less than 6 and 4 g g–1 dry wt,respectively). Selenium ranged between 11–47 g g–1 inlivers. Renal cadmium concentrations were among the highestever published for this species (range: 47–281 g g–1). The regressions of log-transformed concentrations ofthese trace elements in blood samples on those in liver orkidney were significant (all P-values < 0.05) andpositive. However, except for organic mercury (RM 2 = 0.83), the co-efficients of determination were low tomoderate (range of R 2: 0.26–0.52), suggesting poorto moderate predictive capability. Furthermore, therelationships between total mercury in blood and liverchanged between 1997 and 1998, suggesting that it would notbe possible to predict consistently, concentrations ofmercury in blood from those in liver based on samples takenin one year. Blood samples can be used to determineconcentrations of these trace elements in common eiders (andprobably other sea duck species as well). The use of bloodsamples is especially warranted when it is undesirable tokill the animal such as when working with rare or endangeredsea duck species or when the objective is to relate traceelement exposure to annual survival rates. However, thepredictive equations developed here should not be used topredict expected concentrations in one type of tissue fromthose in the other.  相似文献   

19.
Impact of Pollution Caused by Uranium Production on Soil Macrofauna   总被引:1,自引:0,他引:1  
Thirty years of mining and milling activities of the Priargunsky Mining-Chemical Production Company (South-Eastern Siberia, Russia) have resulted in an enrichment of uranium in adjacent steppe soils by a factor of up to 600. A number of attendant pollutants (thorium, arsenic and heavy metals) also have high concentrations in the soil. To estimate the effects of this pollution on soil-living macroinvertebrates, pitfall trapping and core sampling were applied. The element composition of four beetle species was analysed. Soil macroinvertebrates had 3–37 times lower abundance and biodiversity at the contaminated sites compared with the control. Ground beetle communities at the contaminated sites were reduced compared to the control site. The concentrations of uranium and arsenic in beetles collected at the contaminated sites were 2–41 and 2–26 times higher, respectively, than at the control site. There is strong evidence that the contamination caused by uranium production has severe negative biological effects on important groups of the soil food web.  相似文献   

20.
Water requirements to supply human needs lead water stakeholders to store more water during surplus periods to fulfil the demand during – not only – scarcity periods. At the reservoirs, mostly those in semi-arid regions, water level then fluctuates extremely between rises and downward during one single year. Besides of water management implications, changes on physical, chemical and biological dynamics of these drawdown and refilling are little known yet. This paper shows the results, throughout a year, on solids, nutrients (N and P), chlorophyll-a, and sedimentation changes on the dynamics, when the former policy was applied in a reservoir from the semi-arid Northwestern Mexico. Water level sinusoidal trend impinged changes on thermal stratification and mixing, modifying nutrient cycling and primary producer responses. According to nitrogen and phosphorus concentration as well as chlorophyll-a, reservoir was mesotrophic, becoming hypertrophic during drawdown. Nutrient concentrations were high (1.22 ± 0.70 and 0.14 ± 0.12 mg P l−1), increasing phosphorus and lowering N:P significantly throughout the study period, although no intensive agricultural, no urban development, neither industrial activities take place in the watershed. This suggests nutrient recycling complex mechanisms, including nutrient release from the sediment–water interface as the main nutrient pathway when shallowness, at the same time as mineralization, increases. Outflows controlled nitrogen and phosphorus availability on the ecosystem while organic matter depended on river inflows. As on other subtropical aquatic ecosystems, nitrogen limited primary productivity (Spearman correlation R = 0.75) but chlorophyll-a seasonal pattern showed an irregular trend, prompting other no-nutrient related limitants. Shallowness induced a homogeneous temporal pattern on water quality. This observed temporal variability was mainly explained statistically by changes on solids (mineral and organic), chlorophyll-a and flows (62.3%). Annual sedimentation rates of total solids ranged from 11.73 to 16.29 kg m−2 year−1 with organic matter comprising around 30%. N:P ratio on sedimentation rates were as high as could be expected in a resuspension dominated ecosystem, and spatially inverse related with N:P ratio on bottom sediments. Distance from river inlet into the reservoir reveals a marked spatial heterogeneity on solid and nitrogen sedimentation, showing the system dependence on river inflows and supporting resuspension as the main phosphorus pathway. Accretion rates (2.19 ± 0.40 cm year−1) were not related to hydrological variability but decreased with the distance to the river input. Total sediment accumulation (9,895 tons km−2 year−1) denotes siltation as other serious environmental problem in reservoirs but possibly not related with operational procedures.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号