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101.
为探讨沈阳市棋盘山水库湿地保护地近30年生态系统演变规律,文章运用3S技术和景观格局指数,分析了保护地1986~2015年生态系统时空变化及景观格局演变特征。结果表明:1986~2015年间,由于人类活动的干扰,保护地景观破碎度和空间异质性不断增加,水库周边建设用地围绕水库向南部、北部不断扩张,不利于生态系统服务功能的保护和提升,但总体上看,2000~2015年人类活动强度低于1986~2000年,说明该时期生态保护工作取得一定成效。为提升保护地景观质量和生态系统服务功能,提出了保护地生态系统服务可持续管理对策。  相似文献   
102.
受污染原水的弹性填料生物接触氧化处理挂膜试验研究   总被引:20,自引:0,他引:20  
张东  许建华 《重庆环境科学》2001,23(1):59-61,75
试验研究了水温、曝气强度和气水比等因素对YDT生物接触氧化池挂膜的影响。结果表明:生物接触氧化池挂膜受水温影响很大,水温越高,挂膜时间就越短,水温低于15℃自然挂膜难以成功。在挂膜期间,采用较小的曝气强度和气水比可缩短生物膜的成熟时间。对判断生物膜是否成熟的指示性参数-氨氮去除率和CODMn去除率进行了比较,认为用氨氮去除率作为判断生物膜成熟的批示性参数较适合。  相似文献   
103.
青山水库的浮游植物与营养类型评价   总被引:1,自引:0,他引:1  
共鉴定青山水库藻类58属101种,其中有多污水体指示种5种,α-中污水体指示种24种、β-中污水体指示种49种,寡污水体指示种21种。优势种为窄颗粒直链藻(Melosiragranulatavar.angustissima)、颗粒直链藻(M.granulata)和小颤藻(Oscillatoriatenuis)。浮游植物的细胞密度为8.53×107个/L,生物量为16.34mg/L,叶绿素a为16.86mg/m3。根据浮游植物群落结构和水化学分析结果,青山水库已属富营养型水体,并有继续发展的趋势,控制污染,保护水质已刻不容缓。  相似文献   
104.
PCDD, PCDF, AND PCB concentrations in human milk from two areas in Finland   总被引:6,自引:0,他引:6  
Concentrations of 17 toxic 2,3,7,8-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and of 36 polychlorinated biphenyl congeners (PCBs) were analyzed from 167 randomly sampled human milk samples from Southern (77 samples) and Eastern (90) Finland. The level of PCDD/Fs and PCBs in human milk in Southern Finland was about 25% higher than those from Eastern Finland. The level of PCDD/Fs in human milk in Finland was the same as in Sweden, 30–50 % lower than in milk from Central Europe but about 45% higher than values from Norway or Russia. The PCB concentrations in Southern Finland were at the same level as in the Netherlands, and in Eastern Finland at the same level as in Norway. The levels of PCDD/Fs and PCBs decreased with increasing number of children: the third child was exposed to about 70% of the amount of PCDD/Fs and PCBs as compared with the first child, and the eighth to tenth child to about 20%. The congener patterns of PCDD/Fs and PCBs in Finnish human milk were similar to the countries of Central Europe, however, the levels of penta- and heptachlorinated furans were slightly higher than in milk from other countries.  相似文献   
105.
广东省“十三五”环境保护战略思考   总被引:3,自引:0,他引:3  
"十二五"时期,在经济社会稳定发展的背景下,广东省环境保护取得了积极成效,但也存在结构性和格局性污染突出、污染呈现空间扩散态势等问题。在经济新常态背景下,为全面推进广东省"十三五"环境保护工作,在对当前环境问题分析及对未来环境形势研判的基础上,统筹谋划了广东省"十三五"环境保护目标指标及对策建议,以期对广东省率先基本实现现代化和全面建成小康社会起到推动作用。  相似文献   
106.
文章基于"以人为本"的理念,构建了从使用者角度对城市绿地质量评价的简明指标体系,采用多边形综合指标法及德尔菲法,兼顾科学性和可操作性,并应用该指标体系尝试分析南京市城市绿地质量。结果表明:南京城市绿地总体质量处于一般水平,其中公园绿地和风景名胜与自然保护区绿地质量较高。在各项评价指标中,南京居民对绿地管理质量满意度较低,视觉效果满意度、空间布局满意度较高。该评价体系从使用者角度展现了城市绿地的整体水平并直观反映出城市绿地所存在的问题,可为城市绿地规划与管理以及综合评价指标的构建提供重要的依据与参考。  相似文献   
107.
More than 150 scientists from the Americas, Europe, and Asia met in Brno, Czech Republic, in May 2002 at the Second PCB Workshop, entitled “Recent Advances in the Environmental Toxicology and Health Effects of PCBs”. NIEHS/EPA-Superfund Basic Research Program, the Graduate Center for Toxicology at the University of Kentucky, and the Research Centre for Atmospheric and Environmental Chemistry and Ecotoxicology of Masaryk University, Brno, sponsored the Workshop. At six separate sessions (including posters) the origins, human residues and exposures, actions, biomarkers, risk and remediation issues relating to PCBs were discussed.  相似文献   
108.
In recent years, there has been a boom in environmental assessment reports utilizing environmental indicators. Most of these publications are based on the casual chain frameworks (e.g., Pressure–State–Response (PSR), Driving force–State–Response (DSR), and Driving force–Pressure–State–Impact–Response (DPSIR)). These frameworks have made an important contribution by emphasising the importance of causality. However, the reliance on simple uni-directional chains is at the same time not very conducive to a good understanding of the complexity of the processes behind environmental indicators. This limits the usefulness of these frameworks for environmental (impact) assessments. In this paper we propose an enhanced DPSIR (eDPSIR) framework for environmental indicators that takes inter-relations of indicators into account by relying on the use of causal networks rather than causal chains. It will be shown how the concept of causal networks can increase insight into the inter-relation of environmental issues and associated indicators, can facilitate the identification of key indicators for particular kinds of questions, and can provide a useful first step to the establishment of dose–response functions. Working with causal networks can contribute to more appropriate environmental policies and better management decisions.  相似文献   
109.
The use of biological indicators is widespread in environmental monitoring, although it has long been recognised that each bioindicator is generally associated with a range of potential limitations and shortcomings. To circumvent this problem, this study adopted the complementary use of bioindicators representing different trophic levels and providing different type of information, in an innovative approach to integrate knowledge and to estimate the overall health state of ecosystems. The approach is illustrated using mercury contamination in primary producers (mosses), primary consumers (domestic pigeons and red-legged partridges) and top predators (Bonelli's eagles) in southern Portugal. Indicator kriging geostatistics was used to identify the areas where mercury concentration was higher than the median for each species, and to produce an index that combines mercury contamination across trophic levels. Spatial patterns of mercury contamination were consistent across species. The combined index provided a new level of information useful in incorporating measures of overall environmental contamination into pollution studies.  相似文献   
110.
Zhang L  Li J  Zhao Y  Li X  Yang X  Wen S  Cai Z  Wu Y 《Chemosphere》2011,84(5):625-633
Seven polybrominated diphenyl ethers (PBDEs) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) congeners (CB-28, CB-52, CB-101, CB-138, CB-153 and CB-180) were measured in 24 pooled human milk samples comprised of 1237 individual samples from 12 provinces in China. The samples were taken to estimate the background body burden of general population and assess nursing infant exposure via human milk in China. The median concentrations of ∑7PBDEs and ∑6PCBs were 1.49 and 10.50 ng g−1 lipid weight (lw), respectively. BDE-28, BDE-47 and BDE-153 were predominant PBDE congeners accounting for nearly 70% of ∑7PBDEs. As for indicator PCBs, CB-153 was the most abundant congener, followed by CB-138. In our study, there was no significantly statistical relationship between concentrations of PBDEs in milk samples and maternal age as well as dietary habits. ∑7PBDEs did not correlate to ∑6PCBs in Chinese mothers’ milk. The human exposure to indicator PCBs in China was found to be significantly determined by maternal age, dietary habits and geographical factors. It is suggested that Chinese general population is probably exposed to PBDEs with multiple sources and pathways. The estimated daily intakes (EDI) of BDE-47, BDE-99 and BDE-153 for the Chinese nursing infant were much lower than corresponding threshold reference values suggested by USEPA.  相似文献   
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