英国CRTN道路交通噪声预测模型在中国的适用性研究

基于道路交通噪声990 h监测数据,对英国CRTN模型中源强计算模型在中国的适用性进行了验证。试验结果表明,理论计算与实测结果之间平均仅相差0.57 dB（A）,CRTN源强预测模型在中国可以可靠地预测道路交通噪声。     

Seasonal change and correlation with environmental parameters for 2-MIB in Feng-Shen Reservoir, Taiwan

Two common drinking water earthy/musty odorants, 2-methyl-isoborneol (2-MIB) and trans-1,10-dimethyl-trans-9-decalol (geosmin), were monitored and analyzed for their correlation with environmental conditions in Feng-Shen Reservoir (FSR), Taiwan. Long-term monitoring results, from December 2000 to July 2003, indicated that 2-MIB was present in the reservoir at concentrations between 10 and 200 ng L(-1), and those of geosmin were always smaller than 10 ng L(-1). The 2-MIB concentrations followed a trend of higher concentrations during the warm seasons. After being analyzed with 10 water quality and three meteorological parameters, 2-MIB concentration was found to correlate with corresponding air and water temperatures. An analysis of air temperature history versus 2-MIB concentration in FSR suggested that 2-MIB concentration was best correlated with the mean of average daily temperature from 1 to 9 days before sampling, with R (2) = 0.90. This correlation was further employed to predict the 2-MIB concentration observed during another sampling period in FSR. A similar degree of fit was observed between predictions and experimental data, suggesting the potential applicability of the approach. In addition to the effect of temperature, heavy rainfalls that occurred before the sampling time may also reduce the 2-MIB concentration in the reservoir. A short-term continuous monitoring of the odorants for 32 h showed that both geosmin and 2-MIB concentrations in the reservoir remained almost constant, with only about a 10% difference during the sampling period. This may suggest that the odorants were uniformly distributed in the water near the sampling location in the reservoir.     

Evaluation of Traffic Noise Pollution in Amman, Jordan

The City of Amman, Jordan, has been subjected to persistent increase in road traffic due to overall increase in prosperity, fast development and expansion of economy, travel and tourism. This study investigates traffic noise pollution in Amman. Road traffic noise index L ₁₀(1 h) was measured at 28 locations that cover most of the City of Amman. Noise measurements were carried out at these 28 locations two times a day for a period of one hour during the early morning and early evening rush hours, in the presence and absence of a barrier. The Calculation of Road Traffic Noise (CRTN) prediction model was employed to predict noise levels at the locations chosen for the study. Data required for the model include traffic volume, speed, percentage of heavy vehicles, road surface, gradient, obstructions, distance, noise path, intervening ground, effect of shielding, and angle of view. The results of the investigation showed that the minimum and the maximum noise levels are 46 dB(A) and 81 dB(A) during day-time and 58 dB(A) and 71 dB(A) during night-time. The measured noise level exceeded the 62 dB(A) acceptable limit at most of the locations. The CTRN prediction model was successful in predicting noise levels at most of the locations chosen for this investigation, with more accurate predictions for night-time measurements.     

Attitudinal response towards road traffic noise in the industrial town of Asansol, India

The major objective of the investigation was to evaluate the road traffic noise and its likely impacts on the local community of Asansol city (West Bengal, India) by monitoring and modeling. The attitudinal response of local population due to existing vehicular noise is presented in the paper. Noise and Attitudinal Survey was conducted at 25 locations. A total of 869 individuals were surveyed. The relationship between traffic noise levels and annoyance was studied using correlation, linear and multiple linear regressions analysis. The average L(dn) value was 73.28 +/- 8.51 dB(A) (55.1-87.3); The Traffic Noise Index (TNI) was 80.62 +/- 15.88 dB(A) (49.4-115.8). The mean value of percent of population Highly Annoyed (%HA) due to road traffic noise was 26.50 +/- 3.37 (19.44-33.2), whereas the mean dissatisfaction score (MDS) was 2.96 +/- 0.90 (1.04-4.45). Annoyance modeling was also performed based on field data. It can be said that Noise values gives desirable annoyance predicting values in comparison to vehicular data.     

乌鲁木齐—成都 114／113次 旅客列车噪声监测分析

对乌鲁木齐至成都旅客列车车厢内的噪声监测表明,一般情况下车厢内噪声等效A声级不超过铁道部部颁标准要求(TB1932-87).在车厢机械陈旧、路况复杂、隧道、狭谷等情况下,车厢乘务室内噪声等效A声级可达74.9～84.6dB(A),最高超标9.6dB(A),全程超标2.2dB(A).     

噪声背景值修正问题研究

为了解和掌握环境背景噪声对边界噪声监测结果的影响情况，本文就此作了相应的探讨。结果显示：当测量值与背景值的差值超过10dB（A）时，可以忽略背景值对测量结果的影响；当测量值与背景值的差值为3～10dB（A）时，应分段考虑背景值的修正；当测量值与背景值的差值小于3dB（A）时，应重新选择时间进行测定。     

Determination of roadside noise reduction effectiveness of Pinus sylvestris L. and Populus nigra L. in Erzurum, Turkey

This study was carried out to determine the noise-reduction effectiveness of the Pinus sylvestris L. and Populus nigra L. trees along the E-80 State highway in Erzurum-Turkey. Noise values were taken at three measurement points; open (without trees and taken as control), the urban forests of pure P. sylvestris L. and P. nigra L. areas, and at four different distances; 0 (near the noise source), 25, 50 and 75 m from the noise source. At the distance of 25 m from the source, the noise value was 78.5 dB(A) in the control area, which was reduced 75.5 dB(A) and 69.2 dB(A) in the P. nigra L. and P. sylvestris L. areas, with the reduction rates of 24.7 and 31% compared to the control, respectively. This value was 69.6, 67.1 and 64.3 at the distance of 50 m and 64.9, 62.5 and 59.2 at 75 m for the naked, P. nigra L. and P. sylvestris L. areas, respectively. From the results of the study, it was suggested that for the noise pollution from the traffic flow on the roads, in especially the big cities, noise reduction zones with suitable width and plant species should be formed along the main arteries of the cities.     

Dynamics of traffic noise in a tropical city Varanasi and its abatement through vegetation

Noise level monitoring and its reduction with different width and height of vegetation belt were studied in the Varanasi city. Noise level monitoring of the Varanasi city revealed the fact that area category A (without vegetation) was highly polluted as compare to area category B (with vegetation) having less fluctuation of traffic load. Four plant species Putranjeva roxburghi, Cestrum nocturnum, Hibiscus rosasinensis and Murraya peniculata were tested for noise reduction study at different frequencies. Experiment revealed the fact that H. rosasinensis reduced noise highest at both low and high frequencies (100-500 Hz, 22 dB and 2.5-6.3 KHz 26 dB), followed by M. peniculata (100-500 Hz, 18 dB and 2.5-6.3 KHz 20 dB), P. roxburghi (100-500 Hz 15 dB and 2.5-6.3 KHz 17 dB) and C. nocturnum (100-500 Hz 9 dB and 2.5-6.3 KHz 14 dB). Significance of vegetation belt in noise reduction was established with multiple regression models.     

高速公路交通噪声预测模型探讨

针对我国当前广泛使用的2种高速公路噪声预测模型《06规范》预测模型与《09导则》预测模型在预测时比较研究,重点利用环境现状监测数据分别对2种模型验证与对比分析.结果表明,2种模型预测值与实测值相差3dB ～5dB,车流量＞ 300辆/h,《09导则》更接近实测值；在夜间车流量＜300辆/h,《06规范》更接近实测值,2种模型结合采用《06规范》计算的车速,距离衰减考虑车流量的大小,在此基础上应用《09导则》,预测结果与实测值更为接近.     

化学吸收法采集固定污染源氨气的影响因素探究

固定污染源氨气的手工监测，干扰因素较多，其中采样环节尤为关键。实验通过催化氧化-化学发光法考察不同采样管线材质对氨气的吸附效果，离子色谱法考察化学吸收法采集氨气的吸收瓶类型、采样流量、吸收液种类、吸收液浓度及体积等采样条件对氨气吸收效率的影响。实验表明，316 L不锈钢与聚四氟乙烯对氨气的吸附较小，氨气的采样流量不宜超过1.0 L/min,棕色气泡式吸收瓶更适用于氨气样品的采集，磷酸溶液作吸收液对氨气的吸收效率较好，对于低浓度的氨气样品，应采用低流量长时间采集。     

低噪声路面降噪效果研究

通过对公路交通噪声特征,低噪声路面的特点、结构、降噪机理及国内外研究现状的分析,对宁杭高速二期工程低噪声路面与普通路面噪声监测结果进行对比分析,确认低噪声沥青路面具有比较明显的降噪效果,路肩处噪声可降低3～4 dB(A),路外15 m处可降低1.1～3.5 dB(A).     

Calculating of river water quality sampling frequency by the analytic hierarchy process (AHP)

River water quality sampling frequency is an important aspect of the river water quality monitoring network. A suitable sampling frequency for each station as well as for the whole network will provide a measure of the real water quality status for the water quality managers as well as the decision makers. The analytic hierarchy process (AHP) is an effective method for decision analysis and calculation of weighting factors based on multiple criteria to solve complicated problems. This study introduces a new procedure to design river water quality sampling frequency by applying the AHP. We introduce and combine weighting factors of variables with the relative weights of stations to select the sampling frequency for each station, monthly and yearly. The new procedure was applied for Jingmei and Xindian rivers, Taipei, Taiwan. The results showed that sampling frequency should be increased at high weighted stations while decreased at low weighted stations. In addition, a detailed monitoring plan for each station and each month could be scheduled from the output results. Finally, the study showed that the AHP is a suitable method to design a system for sampling frequency as it could combine multiple weights and multiple levels for stations and variables to calculate a final weight for stations, variables, and months.     

噪声自动监测系统的运行维护管理

对噪声自动监测系统在运行过程中遇到的各种情况进行分类和总结,详细介绍了南通市环境监测中心站的相关工作经验,提出从设备故障、突发事件、软件错误等方面出发,对噪声自动监测的运行维护进行综合管理。     

广州市昼夜道路交通噪声的监测与分析

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。     

Application of statistical modeling to optimize a coastal water quality monitoring program

The long-term water quality monitoring program implemented by the Massachusetts Water Resources Authority in 1992 is extensive and has provide substantial understanding of the seasonality of the waters in both Boston Harbor and Massachusetts Bay and the response to improvements in effluent quality and offshore transfer of the effluent in September 2000. The monitoring program was designed with limited knowledge of spatial and temporal variability and long-term trends within the system. This led to an extensive spatial and temporal sampling program. The data through 2003 showed high correlation within physical parameters measured (e.g., salinity, dissolved oxygen) and in biological measures such as chlorophyll fluorescence. To address the potential sampling redundancies in the measurement program, an assessment of the impact of reduced levels of monitoring on the ability to make water quality decisions was completed. The optimization was conducted by applying statistical models that took into account whether there was evidence of a seasonal pattern in the data. The optimization used model survey average readings to identify temporal fixed effects, model survey-average-corrected individual station readings to identify spatial fixed effects, corrected the individual station readings for temporal and spatial fixed effects and derived a correlation model for the corrected data, and applied the correlation model to characterize the correlation of annual average readings from reduced monitoring programs with true parameter levels. Reductions in the number of sampling stations were found less detrimental to the quality of the data for annual decision-making than reductions in the number of surveys per year, although there is less of a difference in this regard for dissolved oxygen than there is for chlorophyll. The analysis led to recommendations for a substantially lower monitoring effort with minimal loss of information. The recommendation supported an annual budget savings of approximately $183,000. Most of the savings was from fewer surveys as approximately $21,000 came from the reduction in the number of stations monitored from 21 to 7 and associated laboratory analytical costs.     

机场周围区域飞机噪声监测方法对比研究

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。     

海口市声环境影响因素分析及预测

噪声污染一直是海口市主要的环境问题之一。主要原因是城市纵深度太低，道路密度太高，交通布局不合理，1991年－2000年城市区域环境噪声和道路交通噪声的平均值分别为59．0dB（A）和69．5dB（A）。利用城市区域环境噪声预测方法和道路交通噪声预测方法对该市噪声进行预测，2001年－2005年该市的区域噪声昼间平均等效声级综合预测值在57．6dB（A）－56．7dB（A）之间；道路交通噪声昼间平均等效声级综合预测值在68．2dB（A）－68．3dB（A）之间。     

Landsat and limnologically derived water quality data: A perspective

Fixed station sampling is the conventional method used to obtain data on the median water quality of reservoirs. A major source of uncertainty associated with this technique is that water quality at the fixed stations may not be representative of the ambient water quality in the reservoir at the time of sampling. This problem is particularly relevant for water quality variables such as chlorophyll, which have a markedly patchy spatial distribution. The use of Landsat reflectance data to estimate median chlorophyll concentrations in Roodeplaat Dam was investigated. A linear polynomial regression model for estimating chlorophyll concentrations from Landsat reflectance data, was firstly calibrated with chlorophyll concentration data obtained by sampling seven fixed stations on the reservoir at the time of the satellite overflight to produce an individual calibration. Secondly, the model was calibrated with a pooled set of sampled data obtained from five separate overflights, to obtain a generalised calibration.It was found that median chlorophyll concentrations determined from Landsat-derived data were similar to median chlorophyll concentrations estimated from fixed station data. However, the range of chlorophyll concentrations in the reservoir estimated from Landsat data was considerably larger than that estimated from fixed station data. Landsat derived estimates of chlorophyll concentrations have the added advantage of providing information on the spatial distribution of chlorophyll in the reservoir.     

Dispersion in Urban Environments; Comparison of Field Measurements with Wind Tunnel Results

A wind tunnel study was performed to determine the dispersion characteristics of vehicle exhaust gases within the urban canopy layer. The results were compared with those from a field monitoring station located in a street canyon with heavy traffic load. The agreement found was fair. In the second part of the paper it is shown how wind tunnel data can be utilized to supplement and thereby enhance the value of field data for model validation purposes. Uncertainty ranges were quantified which are inherent to mean concentration values measured in urban streets.     

测点高度对道路交通噪声监测数据的影响

通过在4城市对132条道路进行了道路交通噪声测点高度试验,系统分析了测点高度从手工监测的1.2 m向自动监测的4.5 m转化后,在不同道路情况对道路交通噪声监测数据的影响。结果表明,测点高度提高后监测结果变化在±3 dB(A)以内。待测道路的车道数和测点与机动车道的距离是其主要影响因素。对两测点高度进行对比,4.5 m高度噪声值随水平距离增加衰减较小,测量结果更稳定。