大气磷干沉降采样方法对比分析

以四川农业大学成都校区为监测点,采用大气主动采样法(AA)、大气干表面法(ADS)及大气湿表面法(AWS)3种常用干沉降采集方法做大气磷干沉降通量对比试验。结果表明,3种采样方法获得的大气磷干沉降通量间具有显著的差异性及相关性(P0.05),三者间可以进行换算统一;AA法适用于较短采样周期的连续性监测研究,ADS法适用于较长采样周期(5 d)的监测研究,而AWS法更适用于在长采样周期(月)内选取一段时间作为干沉降监测的研究。     

新疆大气氮沉降监测研究进展浅析

通过对新疆12个监测点氮沉降研究结果发现,无机活性氮浓度(p NH 4+、p NO 3-、NH 3、NO 2)在不同生态系统存在较大的时空差异,氮沉降通量变化随人为干扰程度呈递增趋势。总结了当前新疆大气氮沉降监测研究进展,包括主要监测方法、不同生态系统大气氮素干沉降的时空差异性分析、大气氮素干湿沉降通量估算。对大气氮素干湿沉降通量的整体估算、不同生态系统的监测常态化等还存在不足,未来评估氮沉降的综合气候效应、定量临界负荷以及生态系统对氮沉降通量急剧增加的响应是今后研究的重点方向。     

太湖大气氮、磷干湿沉降特征

于2018年1—12月,采集太湖湖滨及湖面共计9个点位600多个干湿沉降样品,估算了N、P干、湿沉降率以及全太湖2018年N、P干、湿沉降通量。结果表明,2018年太湖TN和TP月湿沉降率均值分别为161. 2和7. 1 kg/(km~2·月),TN和TP月干沉降率均值分别为103. 6和4. 5 kg/(km~2·月)。TN和TP年干沉降率空间分布规律为:湖面之上开阔水域处的TN和TP年干沉降率大于其他湖滨点位,TN和TP总沉降通量为7 702和333 t/a。2018年相比于2002—2003年,TN和TP总沉降通量分别降低了22. 6%和53. 8%。     

太湖氮磷大气干湿沉降时空特征

为了探索太湖氮磷营养盐干湿沉降特征及对太湖营养盐输入的贡献，于2011年不同季节采集太湖不同位点的大气干湿沉降样品，分析干湿沉降中氮（N）和磷（P）的形态和沉降量。研究结果表明，输入太湖的磷以干沉降为主，而氮以湿沉降为主。在太湖干沉降中总无机氮（TIN）占总氮（TN）的77.1%，溶解性磷（DIP）占总磷（TP）的77.9%。干沉降中TIN主要以NH+4-N为主。西太湖是TN与TP通过大气干湿沉降输入太湖的最高湖区。太湖全年大气TN沉降总量为20 978 t，TP沉降总量为1 268 t，因此，氮磷大气干湿沉降是太湖营养盐输入的重要来源之一。     

地表水水样自然沉降放置试验与讨论

本文用四种方式对地表水样品的自然沉降在采样环节还是在分析环节进行实验,对BOD5、CODMn、CODcr之类分析时不需对样品进行预处理的项目有一定影响,自然沉降在分析环节的监测结果低于在采样环节的监测结果;对氨氮、总磷之类分析时需对样品进行预处理的项目影响几率基本持平。     

冶炼厂周边区域夏季大气Cu和Cd沉降特征

为了解贵溪冶炼厂周边农田区域夏季大气重金属沉降状况,于2012年6—8月及2013年6—8月(夏季),设置8个监测点,共收集大气干湿混合样品48个,采用原子吸收分光光度法分析了Cu、Cd。结果发现,冶炼厂周边区域2012年夏季Cu、Cd沉降通量分别为42.5~421、1.01~5.06 mg/m2,平均值149、2.02 mg/m2;2013年夏季Cu、Cd沉降通量分别为40.6~94.3、0.12~0.44 mg/m2,平均值59.4、0.26 mg/m2。同1月份不同监测点Cu、Cd沉降量存在一定差异性,风向为造成该差异性的主要气象因素;不同监测点Cu、Cd月沉降通量与风向频率均具有显著相关性(r均大于0.60)。降雨量影响Cu、Cd月沉降量,Cu、Cd平均月沉降量与降雨量均呈显著相关关系(r=0.91、r=0.87,P0.05)。     

甘肃河西走廊2001年沙尘暴及其沉降物质观测研究

2001年甘肃河西走廊共发生沙尘暴15次，其特点是时间早、频率快、间隔短，强度大。收集分析其沉降物质，沉降量较高、养分含量较高。     

微风下异龙湖悬浮物沉降与再悬浮研究

在微风或无风条件下,采用沉积物捕获器和Gansith公式对异龙湖水体中颗粒物沉降和再悬浮进行了研究。结果表明:在微风或无风状态下,底泥再悬浮对水体悬浮物含量贡献较大;描述底泥再悬浮的动态过程需要的合适监测时间为48 h。     

干旱区中小城市降雪中金属元素沉降通量研究

文章以干旱区中小城市昌吉市为研究区，选择2011年12月至2012年2月期间较为典型的6场次降雪进行采样，利用ICP-MS测定降雪中20种金属元素，并探讨金属元素的沉降通量、富集特征及其来源。研究表明，降雪中Al的年沉降通量最大，为10.32 mg/m²；Fe、Ba、Zn、V、Cu的年沉降通量次之，集中在1.40~6.11 mg/m²；As、Ni、Mn、Cr、Mo、Sb年沉降通量较小，集中在0.08~0.39 mg/m²；Be、Co、Cd、Pb、Hg、Tl、Th、U的年沉降通量最小，集中在0.001~0.053 mg/m²。Al、Fe、Mn、Be、Th富集系数在0.32~3.05之间，这些金属元素主要来自自然来源；Cd与Hg富集系数分别为923.23、2511.47，达到严重富集的程度；其余金属元素富集系数在10~500之间，属中度富集。昌吉州境内煤炭资源丰富，近年煤炭开采量较大，城区供暖面积不断加大，供暖不断加强；市区车流量急剧增加，运输排放加剧；近郊及周边地区各类工业的分布等是各类金属元素在雪中富集的主要原因。冰雪节后冰灯拆除，降雪可有效捕集大气中的汞，冬季气温不利于Hg挥发等对Hg的严重富集也有重要影响。     

鞍山市大气尘和金属元素沉降通量及污染特征

通过采集鞍山市11个点位的降尘样品以及土壤样品,用ICP-MS分析了Cu、Mn、Zn、Pb等元素含量,并计算其沉降通量。结果表明,鞍山地区大气降尘的沉降通量为2.92～59.8g/(m2.month),其中鞍钢厂区沉降通量均值为31.6g/(m2.month),分别是周边地区和对照地区的4.72倍和10.5倍。重金属As、Cr、Pb和Cd的沉降通量分别为3.78、45.5、42.8、0.457g/(hm2.month)。降尘中各元素的富集系数为0.29～190,其中Cu、Fe、Zn、Mo、Cd、Pb和Se的富集系数大于10,说明这些元素主要来自于人为源。鞍钢厂区土壤中Cu、Pb、Mn、Zn、Mo、Cd、Ca、Fe和Se的含量较辽宁省土壤背景值高,说明其土壤环境已经受到了人类活动的影响。     

南京市郊区基本农田保护区土壤重金属污染调查

为调查基本农田保护区土壤环境中重金属污染状况，江苏省农业环境监测站于1999年和2001年分别对南京市郊区基本农田土壤环境质量进行了监测，共计布设监测点14个，监项目为镉，铅，砷，汞，铬和pH，结果表明，1999年土壤样品的重金属检出率为97．1％，超标率为5．7％，2001年重金属检出率为100％，超标率为1．4％，1999年土壤样品中超标的重金属元素是镉，超标率为28．6％，2001年超标元素是汞，超标率为7．1％，1999年土壤综合污染指数为1．08，污染等级及污染水平均属轻污染；2001年土壤综合污染指数为0．76，污染等级为警戒线，污染水平达到尚清洁。     

马鞍山市城区主干道近地面空气质量调查

为调查马鞍山市城区主干道近地面空气质量状况,马鞍山市环境监测中心站于1999年1月19日～1月21日对城区3条主干道的5个监测点近地面空气质量进行了监测.结果表明,在城市整体环境空气质量良好的情况下,交通干道近地面空气污染较严重,主要污染源是机动车尾气,NOx、CO、TSP是特征性污染物,其中NOx平均分布浓度与车流量近似成正相关,从时间分布上看,NOx平均分布浓度早上最高,晚上次之,中午最低.指出,为改善城市的环境空气质量,必须加强对机动车尾气的监督管理.     

Monitoring of Hydrocarbon Emissions in a Petroleum Refinery

In a petroleum refinery the hydrocarbon emissions which are mostly fugitive in nature are emitted from process, offsites and periodic accidental releases such as: materials storage & handling, process, equipment leaks, solvent evaporation, combustion sources, waste treatment etc. In India, the monitoring of such emissions in a refinery are limited as also the standards are not set for its limit in ambient air. Hence there is an urgent need for generating a database for such emissions. Recently in India, MoEF/CPCB has set some guidelines under CREP rules for monitoring such emissions in a refinery. A detailed monitoring of the hydrocarbon emissions from different sources in a typical 10.5 MMTPA Indian refinery is undertaken during 1999–2001 and the results are presented. It is observed that the storage tank emissions alongwith process leaks form the major contributor towards fugitive hydrocarbon emissions.     

Dual-camera, high-resolution aerial assessment of pipeline revegetation

Energy-extraction results in significant disturbance to rangelands in Wyoming and other western US states. Although reclamation is required by law, US General Accounting Office reports from 1999 and 2005 are clear that affected government agencies have--over much of the past decade--had difficulty accomplishing mandated environmental monitoring of extraction-related disturbance. We evaluated two pipeline rights of way (ROW) using nested images (1- or 2- with 13- or 20-mm ground sample distance (GSD)) acquired during Very-Large Scale Aerial (VLSA) surveys. Aerial monitoring allowed for the collection of large numbers of geocoded samples, and for subsequent cover measurements using methods with demonstrated accuracy equal to that of conventional ground-based methods. Both pipelines had vegetative-cover deficiencies relative to their Plan of Development (POD) requirements. Using bare ground and ground-cover measurements from the higher-resolution imagery, we present a spatial representation of each pipeline ROW that allows quick identification of sections of the ROW that may need further reclamation action to meet POD standards. We also present aerial monitoring costs. We recommend VLSA pipeline surveys as a means for facilitating required environmental monitoring and for addressing the monitoring backlog that has developed with increased energy-extraction activity.     

深圳市河流水质评价指标筛选方案探讨

通过计算各条河流的综合污染指数和各项水质指标的污染分担率,对深圳市8条主要河流1999—2008年水质监测数据进行分析,最终从15项常规水质指标中筛选出氨氮、总磷、生化需氧量、化学需氧量、高锰酸盐指数、石油类、挥发酚、硫化物和六价铬9项指标,建议作为深圳市河流水质评价的统一指标。     

The Ecological Condition of Gulf of Mexico Resources from Perdido Key to Port St. Joe, Florida, USA: Part I. Coastal Beach Resources

Using the approach established by EPA's Environmental Monitoring and Assessment Program (EMAP), a shoreline monitoring survey was conducted in August and September 1999, encompassing the Florida Panhandle from Perdido Key, Florida to Port St. Joe, Florida. The objective of this survey was to demonstrate the use of a probabilistic survey for monitoring and estimating the condition of swimmable beach areas. Thirty stations were sampled using a probabilistic sampling design. Hydrographic data were collected in addition to samples for water chemistry. Bacterial indicators, enterococci and fecal coliforms, were enumerated from the water according to the EPA Beaches Environmental Assessment Closure and Health (BEACH) Program and Florida state guidelines. Additional criteria for site condition included the presence or absence of primary and secondary dunes, anthropogenic debris and vegetation. Based on EMAP evaluation guidelines and Florida state criteria, a baseline assessment of the condition of the Gulf of Mexico beach resources surveyed is presented.     

Monitoring habitat preserves in southern California using high spatial resolution multispectral imagery

Habitat preserve systems have been established adjacent to the densely populated regions of southern California to support indigenous plant and animal species that are listed as rare, threatened, or endangered. Monitoring the condition of habitat across these broad preserves is necessary to ensure their long-term viability and may be effectively accomplished using remote sensing techniques with high spatial resolution visible and near-infrared (VNIR) multispectral imagery. The utility of 1 m spatial resolution VNIR imagery for detailed change detection and monitoring of Mediterranean-type ecosystems is assessed here. Image acquisition and preprocessing procedures were conducted to ensure that image-detected changes represented real changes and not artifacts. Change classification products with six spectral-based transition classes were generated using multiband image differencing (MID) for three change periods: 1998-1999, 1998-2001, and 1998-2005. Land cover changes relevant to habitat quality monitoring such as human-induced disturbance, fire, vegetation growth/recovery, and drought related vegetation stress were readily detected using the multitemporal VNIR imagery. Suggestions for operational habitat monitoring using image products and mobile geographic information system technologies are provided.     

Using landsat data to determine land use/land cover changes in Samsun, Turkey

The rapid industrialization and urbanization of an area require quick preparation of actual land use/land cover (LU/LC) maps in order to detect and avoid overuse and damage of the landscape beyond sustainable development limits. Remote sensing technology fits well for long-term monitoring and assessment of such effects. The aim of this study was to analyze LU/LC changes between 1980 and 1999 in Samsun, Turkey, using satellite images. Three Landsat images from 1980, 1987 and 1999 were used to determine changes. A post classification technique was used based on a hybrid classification approach (unsupervised and supervised). Images were classified into six LU/LC types; urban, agriculture, dense forest, open forest-hazelnut, barren land and water area. It is found that significant changes in land cover occurred over the study period. The results showed an increase in urban, open forest/hazelnut, barren land and water area and a decrease in agriculture and dense forest in between 1980 and 1999. In this period, urban land increased from 0.77% to 2.47% of the total area, primarily due to conversions from agricultural land and forest to a lesser degree. While the area of dense forest decreased from 41.09% to 29.64% of the total area, the area of open forest and hazelnut increased from 6.73% to 11.88%.     

Sources of volatile organic compounds in Cairo’s ambient air

The greater Cairo area suffers from extreme levels of gas and particulate phase air pollutants. In order to reduce the levels of ambient pollution, the USAID and the Egyptian Environmental Affairs Agency (EEAA) have supported the Cairo Air Improvement Project (CAIP). As part of this project, two intensive ambient monitoring studies were carried out during the period of February 22 to March 4 and October 27 to November 27, 1999. Volatile organic compounds (VOCs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. During the February/March study, samples were collected daily, while in the October/November study samples were collected every other day. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. High levels of NMHC were observed at all locations. NMHC concentrations ranged from 365 ppb C at Helwan to 1,848 ppb C at El Qualaly during winter, 1999 and from 461 ppb C at Kaha to 2,037 ppb C at El Qualaly during fall, 1999. El Qualaly, the site chosen to represent mobile emissions, displayed the highest average NMHC concentrations of any site, by a factor of 2 or more. The highest mobile source contributions were estimated at this site. The major contributors to NMHC at all sites were mobile emissions, lead smelting, and compressed natural gas.     

Application of water quality indices and analysis of the surface water quality monitoring network in semiarid North-Central Chile

Surface water quality has increasing importance worldwide and is particularly relevant in the semiarid North-Central Chile, where agriculture and mining activities are imposing heavy pressure on limited water resources. The current study presents the application of a water quality index in four watersheds of the 29°-33°S realm for the period 1999-2008, based on the Canadian Council of Ministers for the Environment approach and the Chilean regulation for irrigation water quality. In addition, two modifications to the index are tested and a comprehensive characterization of the existing monitoring network is performed through cluster analysis. The basins studied show fairly good water quality in the overall, specially the Limarí basin. On the other hand, the lower index values were obtained for the headwaters of Elqui, associated with the El Indio mining district. The first modification of the indicator (i.e., to consider parameters differentially according to their effect on human health or the environment) did not produce major differences with respect to the original index, given the generally good water quality. The second modification (i.e., to consider as threshold values the more restrictive figures derived from a set of regulations) yielded important differences in the indicator values. Finally, an adequate characterization of the monitoring network was obtained. The results presented spatial coherence and the information can be used as a basis for the optimization of the monitoring network if required.