Lithological and geochemical record of anthropogenic changes in recent sediments of a small and shallow lake (Lake Pusty Staw,northern Poland)   总被引：4，自引：0，他引：4  

Wojciech Tylmann 《Journal of Paleolimnology》2005,33(3):313-325

The article presents the results of lithological and geochemical investigations of recent sediments of Lake Pusty Staw. The analysed sediments document about 300 years of the history of this lake. Historical materials indicate that significant changes in the catchment of the lake took place from the beginning of the 18th century (deforestation and afforestation) followed by 19th century tourist development, and 20th century industrialisation. The sediments were dated using the ²¹⁰Pb and ¹³⁷Cs method and core lithology. These made it possible to establish a reliable chronology to the year 1730. The calculated sedimentation rates ranged between 0.17 and 0.83 cm year^–1. There was a period of intensified erosion caused by land clearance between 1734 and 1810, which resulted in an acceleration in sedimentation rate (0.36 cm year^–1) and a change of lithological type of sediment from detritus gyttja to clayey gyttja. On the basis of Cu, Zn, Cd and Pb content in the sediments, it was determined that the beginning of pollution of the lake dates back to the 19th century and was caused probably by the existence of a health resort. A systematic increase in pollution occurred in the 20th century as a result of industrial plants. Normalised with respect to Al, the content of heavy metals in polluted sediments was from several to twenty times higher than in sediments of the preindustrial period, and a comparison of historical materials with changes of sediments in most cases made it possible to identify the direct causes of the increase in pollution.  相似文献   

Atlas and classification scheme of arctic combustion particles suitablefor paleoenvironmental work     

Nancy C.?DoubledayEmail author  John P.?Smol 《Journal of Paleolimnology》2005,33(4):393-431

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Seasonal variations and mechanisms of groundwater nitrate pollution in the Gaza Strip   总被引：4，自引：0，他引：4  

Y.?Abu?Maila  I.?El-Nahal  M.?R.?Al-AghaEmail author 《Environmental Geology》2004,47(1):84-90

Nitrate represents one of the major pollutants of groundwater in the Gaza Strip. Several cases of blue babies disease were reported in the last couple of years. The present study is an investigation of the seasonal variations in nitrate concentration to better understand the mechanisms and parameters controlling this perilous pollutant. Nitrate was analysed in 100 wells (47 agricultural and 53 domestic) in five governorates. The results showed that 90% of the tested wells have nitrate far beyond the allowed values set by the World Health Organization (WHO). The average concentration of nitrate in domestic wells is 128 mg/L in June-July and 118 mg/L in Jan-Feb, and for the agricultural wells, the average is 100 mg/L in June-July, and 96 mg/L for Jan-Feb. The results suggest that the seasonal differences in nitrate concentrations of the domestic wells are slightly more observable than those of the agricultural wells. The environmental factors that control nitrate in groundwater are: a partially-confined aquifer, lack of a sewage system, population density, the presence of refugee camps, the presence of fertilizers and the annual rain. The variations in nitrate concentration of the domestic wells are not of considerable values. It is suggested that concrete policies in pollution control and/or prevention measures could be formulated upon better understanding of the environmental factors.  相似文献   

东胜区污染状况分析   总被引：1，自引：0，他引：1  

侯慧萍  刘克利  金柏青  孙红斌 《内蒙古气象》2009,(2):20-22

文章利用东胜区主要污染源排放情况以及2005年9月1日-2007年8月31日每日SO2、NO2、PM10浓度监测值和2005-2007年SO2、NO2、PM10平均值,分析了东胜区主要污染类型、污染物来源以及东胜区近3年SO2、NO2、PM10监测值日、月、季、年分布特征和变化规律;提出了消减大气污染物排放的对策。  相似文献   

京津冀地区霾成因机制研究进展与展望   总被引：9，自引：3，他引：6  

缪育聪  郑亦佳  王姝  刘树华 《气候与环境研究》2015,20(3):356-368

为满足当前对京津冀地区霾研究和控制的迫切要求,本文梳理了近年来京津冀地区霾的长期变化特征、天气学特征、污染物来源等相关研究成果,发现:从2000年以后,京津冀地区的霾日数呈现出了下降趋势;北京细颗粒物(PM2.5)质量浓度也在总体上呈现下降的趋势,但2013年年均质量浓度仍高达89.5μg m–3,约为我国空气质量标准的3倍(35μg m–3),京津冀空气污染的形势依然严峻;近年来京津冀地区的霾污染事件频发可以归因为不利天气条件与大量污染物人为排放的共同作用;大量的研究表明,区域输送对京津冀地区霾事件的形成和维持有不可忽视的影响;京津冀地区的大气污染不再局限于一时一地,针对重污染天气的预警以及应急控制应该以区域预报为基础实现区域联动;京津冀地区独特的地理环境条件加上城市群的快速发展,形成的局地大气环流也会对局地的污染过程产生重大的影响;大气边界层内气象要素的变化对重污染发生具有显著贡献。京津冀地区的污染控制需要城市群的联动应对治理。  相似文献   

开滦苯加氢精制工程环境风险评价     

王绪鑫  ;徐新阳  ;张宇晨 《辽宁气象》2008,24(1):67-71

以某苯加氢精制工程为例,探讨了焦化行业环境风险评价方法;利用该项目所在地近3 a地面常规气象观测资料,分析了当地的污染气象特征;采用风险识别、源项分析、后果计算、风险评价等环境风险评价技术方法,筛选出主要风险因子并进行风险预测,采用多烟团模式并考虑气象因素进行风险计算。结果表明：污染事故发生后,苯类物质的地面浓度最大值为3 214 mg/m^3,位于距离事故发生源WNW方向约50 m处超标1 339倍,由此可知近距离污染严重;高浓度污染物主要集中在污染源附近,随着距离的延长,污染物浓度不断向下风向扩散,超标范围在6 km内。利用简化分析法,定量给出此项工程的最大可信事故风险值为7.6×10^-6/a,小于化工行业风险值8.33×10^-5/a,此工程风险值水平与同行业比较在可接受的范围内。  相似文献   

Impact of mining activities on soils and sediments at the historical mining area in Podljubelj,NW Slovenia     

Tamara Teršič  Mateja Gosar  Robert Šajn 《Journal of Geochemical Exploration》2009

The abandoned Hg mine in Podljubelj was in operation with interceptions from 1557 to 1902. The entire operating period yielded about 110 000 tons of ore, from which 360 tons of Hg was produced. The objective of the research project was to establish the contents and spatial distribution of Hg in soils and stream sediments in the vicinity of the mine. On an area of 88 ha the soil was sampled in a 100 × 100 m grid. Two soil horizons (0–5 cm and 20–30 cm) were sampled in order to distinguish between geogenic and anthropogenic Hg sources. It was established that on an area of about 9 ha Hg content in soil exceeds The New Dutchlist action value for Hg (10 mg/kg). Total Hg concentrations in soil samples vary between 0.17 and 719 mg/kg, with a mean of 3.0 mg/kg. Mercury contents in stream sediments range from 0.065 to 1.4 mg/kg, with a mean of 0.64 mg/kg. The highest determined value in soils was found in the area around the former roasting furnace, where the ore was processed. Increased Hg concentrations were also found on the mine waste dump (108 mg/kg). Mercury contents in soils generally decrease with soil profile depth and with the distance from the mine and from the roasting furnace location. Mercury also appears in higher concentrations along the road that runs through the valley, which results from the use of Hg-bearing ore residues in road construction. The average enrichment factor (EF) of Hg in topsoil with respect to subsoil is 3.3. Calculated enrichment factors show higher values also for Cd (3.2), Pb (2.7), Ca (2.4) and P (1.9). The average enrichment factor of Hg in topsoil with regard to the established Slovenian soil averages (EF_slo) is 19. EF_slo of other determined chemical elements do not exceed 3.0.  相似文献   

高光谱遥感技术在水环境监测中的应用研究   总被引：26，自引：4，他引：26  

万余庆  张凤丽  闫永忠 《国土资源遥感》2003,14(3):10-14

以黄土高原几类常见土壤为试验品,定量研究了不同泥土含量与水体光谱反射率的关系,探索了利用反射率反演水体深度的方法。文中还介绍了利用高光谱遥感技术分析水污染类型和强度的方法。最后以靖边县城的芦河为例,分析了高光谱遥感探测水污染程度的可行性。  相似文献   

广东雷州珍稀海洋生物国家级自然保护区水体和沉积物中石油类含量与分布特征          下载免费PDF全文

刘芳  柯盛  周立喜  陈成琼  陈耀 《海洋开发与管理》2020,37(1):69-74

为了探讨广东雷州珍稀海洋生物国家级自然保护区海域水体和沉积物中石油类的含量及其分布特征,文章于2017年和2018年分别对保护区海域的石油类进行了调查。结果表明,保护区表层水体石油类含量为0.003~0.066mg/L,平均含量为0.015mg/L,平均污染指数为0.30,保护区水体中的石油类基本符合一类海水水质标准。保护区表层沉积物中石油类含量为3.0~54.8mg/kg,平均值为11.109mg/kg,符合海洋沉积物第一类质量标准。保护区水体和沉积物中石油类含量的变化规律基本相似,但是沉积物中石油类含量的变化更大。根据调查数据分析,保护区水体中石油类的主要来源是保护区社区小型渔船航行排放的石油类,以及保护区周边渔船在航行过程排放的石油类扩散到保护区海域。  相似文献   

钦州湾海洋环境的富营养化水平评价及其对浮游植物叶绿素a的影响          下载免费PDF全文

康建华  林毅力  王雨  蓝文陆 《海洋开发与管理》2020,37(11):67-74

文章通过钦州湾现场调查资料，分别利用单因子污染指数法和富营养化指数法对湾内水质的污染状况和富营养化水平进行评价，并分析讨论不同的富营养化水平条件下浮游植物叶绿素a的响应。结果显示，钦州湾的污染状况和富营养化程度从湾顶至湾外呈现由重至轻的梯度变化，并出现两个“极端区域”：茅尾海化学需氧量（COD）和营养盐的污染指数劣于三类海水水质标准并重度富营养化；外湾污染指数符合一类海水水质标准并贫营养化。分析表明，茅尾海的重度富营养化是由河流输入、相对封闭的地形以及过度的牡蛎养殖造成，而外湾的贫营养化则主要归因于较少的水产养殖和陆源污水排放以及大量的浮游植物对磷酸盐的消耗。叶绿素a在这两个区域均呈现低值，茅尾海内主要是由于贝类滤食大粒径浮游植物和真光层深度下降引起，而外湾则是氮磷比（N/P）失衡，浮游植物生长受磷限制导致。另外，核电站温排水有可能是导致叶绿素a较高的原因。减少茅尾海内的养殖规模，种植红树林，集中污水于外湾排放，加强温排水口的水质监控是保证钦州湾海洋生态环境可持续发展的手段。  相似文献