北京市某高层建筑高空电磁辐射环境影响分析

选取北京市某代表性高层居民楼顶平台作为高空电磁辐射环境水平监测点进行综合场强和选频监测，评价总体电磁辐射环境水平，并分析监测区域电磁辐射能量的来源。结果表明：该高空监测区域的电磁辐射环境总体水平低于国家规定的公众照射导出限值，但高于地面水平。监测区域主要受30 km 外的中波台影响，其次是9 km 外的中央电视塔。影响最大的是639 kHz频率的中波信号，占100 kHz～300 MHz总场强的95％以上，其次是1．28 MHz频率的中波信号。提出，开展敏感建筑物规划建设时，应考虑中波的传播特性和对环境的影响。     

微波通信对环境的影响

微波通信产生的电磁辐射当超出一定强度时将对空间环境产生污染,对人体健康构成威胁,国际上若干国家制定了微波段电磁辐射的环境安全标准,但相差较大,如苏美两国的标准相差达100倍。本文根据我国多所医科大学的现场监测和卫生调查结果提出采用0.3微瓦/厘米~2作为微波电磁辐射的标准。 对其环境影响评价方法,本文根据微波辐射的特点和空间传播无吸收衰减,从理论上建立数学模型,提出场强、电磁能量衰减值、估算处电平、功率密度值。安全静空距离、建筑物的高度的计算方法。     

中央广播电视发射塔环境电磁辐射测试研究

对发射７套电视节目和５套调频节目，发射总功率２４０ＫＷ的中央广播电视塔电磁辐射场强监测结果表明：（１）由于节目频率不同，发射机功率及发射天线形式、高度、增益不同，电磁波到达地面最大场强值的距离是不同的；在近距离内高层建筑各层所接收到的场强大小也是不同的。（２）电视与调频信号在近距离昼夜电平无明显变化。（３）电视塔周围２０００米内环境综合场强最大值为２８４～３２８μＷ／ｃｍ２，所有环境测量值均小于公众导出限值４０μＷ／ｃｍ２。     

基于相位差的多系统通信基站的电磁辐射监测

在安徽宣城通信基站中选取103个基站并设置924个监测点位,用电磁辐射分析仪监测,利用相位差确定所属区域后对基站电磁辐射强度作理论预测,与现场监测值对比分析。结果表明,现场监测电场强度值为0. 20 V/m～1. 86 V/m,均值为0. 45 V/m;功率密度为0. 011μW/m~2～0. 918μW/m~2,均值为0. 063μW/m~2,远小于标准限值。说明该区电磁环境状况整体较好,基站周围电磁辐射随着距离的增大而不断减小,功率密度实测值变化趋势与理论预测值基本一致。     

调幅广播天线发射区电磁辐射监测评价

甘肃省调幅广播发射台位于兰州市黄河北岸的赵家庄，为了摸清了广播天线发射区周围电磁辐射污染状况，对天线发射区２００ｍ内电磁辐射场强进行了监测，根据电磁辐射场强衰减曲线，分析场强衰减规律，按照ＧＢ８７０２－８８《电磁辐射防护规定》中公众照射标准，评价天线发射区中磁辐射污染对环境的影响。     

泉州市移动通信基站电磁辐射环境影响分析

对泉州市移动通信GSM基站和TD—SCDMA基站电磁辐射状况进行监测与分析。通过理论计算预测基站电磁辐射安全距离，对典型敏感目标、典型基站进行电磁辐射的监测，结果与理论预测情况相符。选取302个GSM基站和306个TD—SCDMA基站进行电磁辐射的监测，结果表明，各基站电磁辐射满足单个项目管理低于目标限值0．08W／m2的标准。分析表明，基站在正常运行时，对周围的电磁辐射环境影响能满足国家相应标准的要求。     

中波发射台电磁辐射环境影响理论预测与模拟类比方法的比较分析

中波台发射设备项目电磁辐射环境影响评价采用理论计算和模拟类比方法结果一致，运用理论计算方法评价结果相对偏安全。     

城市移动通信基站电磁辐射环境调查与评价——以连云港为例

对连云港移动通信基站电磁辐射环境进行现状调查与评价,将3个时段内移动基站电磁辐射监测数据进行统计分析和分区评价。结果表明,监测数据均能符合相应的环境标准,县域电磁环境辐射水平整体略低于城市区域,基站周边整体受电磁辐射影响程度随高度上升呈增加趋势,10 m～15 m高度处的综合场强平均峰值最高。     

移动通讯发射基站功率密度对辐射环境影响分析

采用理论预测和实际测量的方法,对辽宁省移动通信有限公司的发射基站的电磁辐射对周边环境的影响做出预测并实际测量了场强,测算出污染半径及范围,为环境管理提供了技术支持。     

重庆市住宅楼环境电磁辐射的初步测量与分析

初步探测重庆市住宅楼环境电磁辐射的现状及其影响因素,为建立人居环境电磁场特征数据库提供依据。按照国家标准的要求和方法,在重庆市选择4个典型居住小区,分别测量各小区住宅楼不同楼层电梯门口或楼梯间以及各住宅楼楼顶的电磁辐射水平,结果表明,本次横断面调查中,在1MHz～40GHz频段,各栋楼的综合场强为17.13～17.18V/m,已接近GB 8702-88《电磁辐射防护规定》的公众照射导出限值,各楼层间差异无统计学意义(P>0.05)。在5～1000Hz频段,各栋楼楼内综合场强分布差异无统计学意义(P>0.05),而临近高压线的住宅楼楼顶综合场强明显高于其他小区楼顶以及同一栋楼其他楼层的综合场强(P<0.05),并且该楼各楼层的磁场强度明显高于其他住宅楼(P<0.05)。所测住宅楼的环境电磁辐射水平未超出国家相应标准限制,不同楼层电磁辐射水平与极低频辐射源的分布有关。     

移动通信基站架设方式对地面电磁辐射分布的影响

选取南通市具有代表性的9种不同架设类型的基站现场实测,分析其地面水平方向上的电磁辐射分布特征,以掌握基站不同架设方式对地面电磁辐射的影响。结果表明:天线架设方式不同,地面电磁辐射强度及分布存在一定差异,落地塔监测值整体低于楼顶塔。50 m范围内,功率密度值由大到小依次是楼顶抱杆楼顶井字塔楼顶角钢塔楼顶景观塔楼顶集束天线楼顶拉线塔楼顶四角塔楼顶美化天线落地塔,地面最大值普遍出现在距离基站20 m~30 m范围。受天线架设高度、下倾角因素的影响,楼顶美化天线和楼顶角钢塔地面最大值点分别出现在距离基站60 m和70 m处,超出监测点位50 m布设范围。     

中短波广播发射台电磁辐射环境影响预测模型

为预测中短波广播发射台的电磁辐射环境影响,根据国家相关电磁辐射标准,研究和分析了中短波广播发射台电磁辐射环境影响理论预测模型,编辑了中短波发射台电磁辐射环境影响计算分析程序,验证发现实际监测符合理论预测.实例计算了中短波发射台周围的电磁辐射影响,表明程序的计算结果可用于指导中短波发射台周围的建设.     

Sensitivity analysis of TOPSIS method in water quality assessment II: sensitivity to the index input data

This is the second part of the study on sensitivity analysis of the technique for order preference by similarity to ideal solution (TOPSIS) method in water quality assessment. In the present study, the sensitivity of the TOPSIS method to the index input data was investigated. The sensitivity was first theoretically analyzed under two major assumptions. One assumption was that one index or more of the samples were perturbed with the same ratio while other indices kept unchanged. The other one was that all indices of a given sample were changed simultaneously with the same ratio, while the indices of other samples were unchanged. Furthermore, a case study under assumption 2 was also carried out in this paper. When the same indices of different water samples are changed simultaneously with the same variation ratio, the final water quality assessment results will not be influenced at all. When the input data of all indices of a given sample are perturbed with the same variation ratio, the assessment values of all samples will be influenced theoretically. However, the case study shows that only the perturbed sample is sensitive to the variation, and a simple linear equation representing the relation between the closeness coefficient (CC) values of the perturbed sample and variation ratios can be derived under the assumption 2. This linear equation can be used for determining the sample orders under various variation ratios.     

Heat wave hazard classification and risk assessment using artificial intelligence fuzzy logic

The average summer temperatures as well as the frequency and intensity of hot days and heat waves are expected to increase due to climate change. Motivated by this consequence, we propose a methodology to evaluate the monthly heat wave hazard and risk and its spatial distribution within large cities. A simple urban climate model with assimilated satellite-derived land surface temperature images was used to generate a historic database of urban air temperature fields. Heat wave hazard was then estimated from the analysis of these hourly air temperatures distributed at a 1-km grid over Athens, Greece, by identifying the areas that are more likely to suffer higher temperatures in the case of a heat wave event. Innovation lies in the artificial intelligence fuzzy logic model that was used to classify the heat waves from mild to extreme by taking into consideration their duration, intensity and time of occurrence. The monthly hazard was subsequently estimated as the cumulative effect from the individual heat waves that occurred at each grid cell during a month. Finally, monthly heat wave risk maps were produced integrating geospatial information on the population vulnerability to heat waves calculated from socio-economic variables.     

Austal 2000应用于国内“烟塔合一”类项目大气影响评价

简述了德国"烟塔合一"类大气污染扩散模式,以及相关模式Austal 2000的应用方法,修正了气象参数以适合本地化应用。以天津某电厂为实例,将Austal 2000模式"烟塔合一"和烟囱排烟方式的计算结果进行了对比分析。结果表明,在进行本地化修改后,Austal 2000模式适用于国内有关项目大气预测评价,但从环境影响角度考虑,"烟塔合一"相对于高烟囱排放方式没有明显优势,应用时需慎重。     

Oasis land-use change and its effects on the eco-environment in Yanqi Basin, Xinjiang, China

Satellite data and the published coefficients about the world's and China's ecosystem were used to analyze the effects of land-use changes on the ecosystem service in the Yanqi Basin. Both economic developments and arid, fragile ecosystems have strongly affected the land use. A sensitivity analysis determined the effect of manipulating the coefficients on the estimated values. Results indicated that (1) the total value of ecosystem services in the Yanqi Basin were 9,374.66, 10,450.52, 9,964.20, and 9,8707.77 million Yuan in 1990, 2000, 2005, and 2011, respectively. The net increase in ecosystem service values were about 496.11 million Yuan within 1990–2011; (2) The aggregated ecosystem service values of water body, wetlands, grasslands, and croplands were about 99.25 % of the total value; (3) Waste treatment and soil formation were the top two ecological functions with high service values and contributing about 61.70 % of the total service values; and (4) Ecosystem service values estimated in this study were inelastic with respect to the value coefficients; therefore, the estimation was robust in spite of uncertainties on the value coefficients. A reasonable land-use plan should be based on rigorous environmental impact analyses for maintaining stability and sustainable development of the Yanqi Basin.     

Long-term investigations of post-Chernobyl radiocaesium in fallout and air in North Croatia

The long-term behaviour of (137)Cs activity concentrations in air and fallout has been studied in the city of Zagreb for the post-Chernobyl period (1986-2006) as a part of an extended monitoring program of radioactive contamination of human environment in Croatia. Annual mean (137)Cs activity concentrations in air and annual total deposition fluxes (wet plus dry) decreased from 2.8 x 10(-4) Bq m(-3) in September 1986 to 3.0 x 10(-6) Bq m(-3) in last quarter of 2006 and from 6,410 Bq m(-2) year(-1) in 1986 to 2 Bq m(-2) year(-1) in 2006 respectively. By fitting the measured (137)Cs activity concentrations to the theoretical curve the ecological half-lives of (137)Cs in air and fallout were estimated with respective values of 0.46 and 0.54 years for immediate post-Chernobyl period, increasing to 5.52 and 3.97 years afterwards. Using the data on (137)Cs activity concentrations in air and fallout total caesium deposition velocity of (3.34 +/- 3.13) x 10(-2) ms(-1) was estimated with median value being 2.13 x 10(-2) ms(-1). Such relatively high (137)Cs deposition velocities compared with pre-Chernobyl ones, are characteristic for the post-Chernobyl period and, according to Stokes' settling law, indicate that the diameters of aerosol particles associated with (137)Cs originated from the Chernobyl accident are pretty large, i.e. >1 microm. (134)Cs/(137)Cs activity ratio in fallout and in air has been found to be similar to the theoretically predicted values, initial value being about 0.5 and decreasing according to differential radioactive decay. The similar ratio has been observed in most of the other environmental samples.     

Design and assembly of an experimental laboratory for the study of atmosphere–plant interactions in the system of fumigation chambers

A 5-day biochemical oxygen demand (BOD(5)) test has been used as the standard measurement of organic pollution in rivers worldwide. However, it may be argued that BOD is not a sufficient indicator of organic pollution when nitrogenous biochemical oxygen demand (NBOD) is present in water samples. In this study, BOD, NBOD, and carbonaceous biochemical oxygen demand (CBOD) of treated sewage effluent (TSE) were measured near at the discharge outlet of 3 sewage treatment plants (STPs) in Sakai, Itachi, and Kashio rivers in Central Japan. Additional measurements were conducted at one point upstream and two points downstream from the STP discharge points in the rivers. It was estimated that NBOD values in the TSE of Sakai River, Kashio River and Itachi River accounted for 54%, 69% and 18% of their BOD values, respectively. Respective NH4+ and NO2- concentrations were positively correlated with those of NBOD values in Sakai, Itachi, and Kashio rivers. The BOD loads from the TSE were estimated to be 2.2, 5.7, and 1.2 times higher than the CBOD loads in the Sakai, Itachi, and Kashio rivers, respectively. The variation of the portion of NBOD values of each TSE, as well as the ratios of CBOD to BOD loads, was attributed to the difference in each STP system. Consequently, the NH4+ and NO2- of TSE led to the increase of NBOD in the Sakai River basin.     

Labile pools of Pb in vegetable-growing soils investigated by an isotope dilution method and its influence on soil pH

Pollution of Pb in the surface of agricultural soils is of increasing concern due to its serious impact on the plant growth and the human health through the food chain. However, the mobility, activity and bioavailability of Pb rely mainly on its various chemical species in soils. In the present study, E and L values, the labile pools of isotopically exchangeable Pb, were estimated using the method of isotope dilution in three vegetable-growing soils. The experiments involved adding a stable enriched isotope ((206)Pb > 96%) to a soil suspension and to soils in which plants are subsequently grown, the labile pools of Pb were then estimated by measuring the isotopic composition of Pb in soil solutions and in the plant tissues, respectively. In addition, the correlation of E values and soil pH was investigated at the ranges of pH 4.5-7.0. The amount of labile Pb in soils was also estimated using different single chemical extractants and a modified BCR approach. The results showed that after spiking the enriched isotopes of (206)Pb (>96%) for 24 hours an equilibration of isotopic exchanges in soil suspensions was achieved, and the isotope ratios of (208)Pb/(206)Pb measured at that time was used for calculating the E(24 h) values. The labile pools of Pb by %E(24 h) values, ranging from 53.2% to 61.7% with an average 57%, were found to be significantly higher (p < 0.05) than the values estimated with L values, single chemical extractants and the Σ(BCR) values obtained with the BCR approach, respectively. A strong negative correlation (R(2) = 0.984) between E(24 h) values and soil pH was found in the tested soil sample. The results indicate that the %E(24 h) value can more rapidly and easily predict the labile pools of Pb in soils compared with L values, but it might be readily overestimated because of the artificial soil acidity derived from the spiked isotopic tracer and the excess of spiked enriched isotopes. The results also suggest that the amounts of Pb extracted with EDTA and the Σ(BCR) values extracted with the modified BCR approach are helpful to detect the labile pools of Pb in soils. In addition, the negative correlation between soil pH and the labile pools of Pb in soils may be useful for further remediation to reduce the bioavailability of Pb in contaminated soils.     

楼顶式移动基站电磁辐射污染调查

对南通市楼顶式移动基站电磁辐射污染进行了调查。结果表明,南通市418个楼顶站基站周边地面50 m范围内电磁辐射功率密度值均能满足《电磁环境控制限值》(GB 8702—2014)的要求;楼顶美化天线、集束天线和景观塔等建设较晚的楼顶塔形地面电磁辐射强度相对较小,楼顶角钢塔、拉线塔和抱杆等建设较早的塔形地面电磁辐射强度相对较大;楼顶塔所在楼顶平台监测值存在轻度超标的情况。提出,应严格控制楼顶塔所在楼顶的人员可达性,即基站电磁辐射防护区应高出楼顶2 m以上,避免公众进入基站电磁辐射防护区内,受到基站天线的过量辐射影响。