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51.
Anttila A Leppänen AP Rissanen K Ylipieti J 《Journal of environmental radioactivity》2011,102(7):659-666
Samples of summer pasture plants that reindeer feed on were collected in order to study 137Cs concentrations in different plant species and in species nested in certain site types, and to study the regional distribution of 137Cs in the Finnish reindeer management area. Plant species were categorized by the site types of mineral soil forest (xeric heath forest and mesic heath forest) and peatland. A third category called ’other plant species’ included plants with various site types, poorly determined species and species with poor statistics. The 137Cs concentrations in different site types differed significantly. The mean 137Cs concentrations of the whole reindeer management area in the xeric heath forest plant species was 44 ± 27 Bq/kg dw, in the mesic heath forest plant species 75 ± 59 Bq/kg dw and in the peatland plant species 219 ± 150 Bq/kg dw. The peatland species uptake 137Cs more efficiently than plant species of mineral soil forests. A particularly efficient collector of 137Cs was Trichophorum sp. It is suggested that Trichophorum sp. could be used as an indicator species for reindeer summer fodder plants. The highest concentrations of 137Cs were found in Southern Lapland and the lowest in Northern Lapland. Today, the concentrations of 137Cs in summer pasture plants that reindeer feed on in Finland are at such a level that there is no need to avoid any plant species. In the case of future nuclear fallout, reindeer grazing in peatlands would increase concentrations of 137Cs in reindeer meat. 相似文献
52.
Gordon Nigh 《Environmental management》1998,22(2):197-202
/ British Columbia has an ecosystem classification system that classifies sites into site series. Foresters commonly measure the productivity of these sites by their site index. In British Columbia, site index is defined as the height of a stand at breast height age 50 and is usually estimated from height-age models. Biogeoclimatic site series/site index relationships are an increasingly popular method of estimating site index in British Columbia for stands where site index cannot be reliably estimated with height-age models. The precision of the predicted site index from these relationships can be evaluated with prediction intervals. This is done for the predicted site index of a single site, a group of sites, or the areally weighted site index of a group of sites. The methodology is also useful in determining the number of sites required to meet a specified precision. These prediction intervals will assist foresters in making sound forest management decisions.KEY WORDS: Biogeoclimatic Ecosystem Classification; Precision; Prediction interval; Site index; Site series 相似文献
53.
郑州市总量排污收费试点方案的理论依据和制定原则 总被引:1,自引:0,他引:1
选择使用排污费刺激消减和筹集资金的功能,利用污染边际处理费用(成本)法和费用分摊法的原理,在国家总量排污收费试点方案的基础上,制定地郑州市总量排污收费试点方案征收标准,实施后取利了显著成效。 相似文献
54.
应用全场数学模型模拟了深圳排海的市政污水中悬浮物、化学需氧量、无机氮、活性磷酸盐及大肠菌群5个污染因子在海域大潮和小潮时对海域面积的影响。指出在不同水文条件和23m^3/d排放量下,不同质量浓度的活性磷酸盐和大肠菌群超过Ⅲ类海水水质标准的影响面积在大潮时分别为0.04km^2和7.72km^2,小潮时分别大于0.08km^2和6.16km^2;无机氮由于海水本底值较高,使得这一指标在全海域内超过Ⅲ类海水水质标准;而化学需氧量和总悬浮物质量浓度符合Ⅲ类海水水质标准。通过将现场监测资料用数模计算,提出排海污水混合区面积为1.5km^2。同时还引用部分国外的计算公式,对几种混合区允许范围进行了估算。 相似文献
55.
56.
The benefits of strategic environmental considerations in the process of siting a repository for low- and intermediate-level radioactive waste (LILW) are presented. The benefits have been explored by analyzing differences between the two site selection processes. One is a so-called official site selection process, which is implemented by the Agency for radwaste management (ARAO); the other is an optimization process suggested by experts working in the area of environmental impact assessment (EIA) and land-use (spatial) planning. The criteria on which the comparison of the results of the two site selection processes has been based are spatial organization, environmental impact, safety in terms of potential exposure of the population to radioactivity released from the repository, and feasibility of the repository from the technical, financial/economic and social point of view (the latter relates to consent by the local community for siting the repository). The site selection processes have been compared with the support of the decision expert system named DEX. The results of the comparison indicate that the sites selected by ARAO meet fewer suitability criteria than those identified by applying strategic environmental considerations in the framework of the optimization process. This result stands when taking into account spatial, environmental, safety and technical feasibility points of view. Acceptability of a site by a local community could not have been tested, since the formal site selection process has not yet been concluded; this remains as an uncertain and open point of the comparison. 相似文献
57.
Gilad Chen 《组织行为杂志》2012,33(2):153-160
In 1997, Judge, Locke, and Durham published the core self‐evaluations (CSE) theory proposing that a multidimensional CSE construct, composed of emotional stability, self‐esteem, locus of control, and generalized self‐efficacy, accounts for individual differences in job satisfaction as well as in other organizational behavior outcomes. In this article, I argue that, despite ample evidence in support of the predictive validity of the CSE construct, the adequacy of including emotional stability, self‐esteem, locus of control, and generalized self‐efficacy as indicators of the CSE construct may be questionable, and I review evidence that points to limited convergent and discriminant validity of the CSE construct. I conclude the article with a few recommendations for advancing CSE theory and research. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
58.
Oyster culture has a potential to generate income for coastal communities and to lessen pressure on natural overexploited populations. A project to transfer mangrove oyster Crassostrea rhizophorae raft culture technology to selected coastal communities in Margarita Island, Venezuela is being developed, and an optimum location selection technique was devised. To pick the variables or factors that determine site suitability, a bibliographic database was made, aspects of interest chosen, and the most comprehensive ones singled out, eliminating redundant ones. Twenty variables were grouped in criteria based on the way they influence the project. Variables were classified as intrinsic environmental, environmental extrinsic, logistic, and socioeconomic criteria. Thirty-five experts were asked to evaluate the factors and to score each according to their suitability weight. Logistic criterion received the highest values, followed by environmental extrinsic issues. A Geographic Information System using a base map compiled from 1:25,000 scale maps was developed. A thematic map for each factor was completed, dividing graphically the 3896-km2 study area into polygons of equal weight for each factor. The Multi-Criteria Evaluation (MCE) was used to combine the variables. Resultant vectors in thematic maps were added to obtain smaller polygons with the same value sum. Finally, MCE was used to generate a final output: the optimum sites for oyster aquaculture resulting from the added values of over 3000 polygons in the maps, for the 20 criteria. Higher scores were reached in 13 areas covering 4.1 km2, those places having the optimum conditions for oyster raft aquaculture in the region. Additional locations meeting 75% to 70% of the demanded criteria for a final suitable selection cover 137 sites encompassing 37.5 km2. 相似文献
59.
Evelyn A. Howell 《Environmental management》1981,5(3):207-212
The process of analyzing vegetation in terms of its suitability for various non-consumptive uses is primitive in comparison with systems for evaluating other resources such as soil and topography. This paper proposes a framework for developing a standardized, quantitative vegetation analysis system based on plant ecology methods. A tentative scheme under study in Wisconsin is presented for discussion purposes. 相似文献
60.
GONTRAN F. BAGE RÉJEAN SAMSON BERNARD SINCLAIR-DESGAGNÉ 《Environmental management》2002,30(6):0807-0815
A technicoeconomic model is developed to select an optimal strategy for the remediation of a contaminated site and to determine
the value of this remediation strategy. The model is an extension of actual cost–benefit analysis, with consideration of “irreversible”
remediation technology choices, technology effectiveness, and uncertainty on the site's level of contamination. The model
considers the possibility of reducing uncertainty by both acquiring more and better information on the level of contamination
and by offering the decision-maker the opportunity to reevaluate his decision and switch to a more appropriate technology.
It is believed that this model will help decision-makers in the selection of a remediation strategy by presenting all potentially
feasible strategies, and how uncertainty on the site's level of contamination affects these strategies. 相似文献