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611.
大学生环境意识调查与环境教育刍议 总被引:7,自引:1,他引:7
对云师大学生的问卷调查表明,大学生整体的环境意识不强,但对环境的参与意愿和关注程度较高,对环境偏于从社会观角度理解,环境观的系统性和整体性较差,但对接受系统环境教育持积极态度。 相似文献
612.
对2001-2005年大庆水库的底栖动物进行了生态调查.共观察到4科7属底栖动物,其中:软体动物为1科1属,环节动物为1科2属,水生昆虫为1科3属,甲壳动物为1科1属;底栖动物的密度变化范围为96~880个/平方米;优势种属是前突摇蚊属(Procladicus)和摇蚊属(Chironomus).运用生物学污染指数(BPI-Biology Pollution Index)来评价大庆水库水质,评价结果表明:BPI指数变化范围为0.73~0.82,水质属于β中污染水体,五年之间的水污染程度变化不明显,而且水质逐年有略微好转的倾向;平水期的水质略好于丰水期的水质. 相似文献
613.
淮安湿地现状调查和可持续发展 总被引:2,自引:0,他引:2
从2004-2006年上半年以来,对淮安市的湿地现状进行了调查,并对其功能、效益进行了分析,指出了淮安市湿地保护存在的问题,同时强调必须要运用宣传教育、科学规划、统筹兼顾、协调管理、加大投入等手段来保护生物多样性,实现环境、经济、社会效益的可持续发展。 相似文献
614.
615.
Application of geostatistical methods to arsenic data from soil samples of the Cova dos Mouros mine (Vila Verde-Portugal) 总被引:3,自引:0,他引:3
A total of 286 soil samples were collected in the Cova dos Mouros area. All samples were dry sieved into the <200 mesh size fraction and analysed for Fe, Cu, Zn, Pb, Co, Ni, Bi and Mn by atomic absorption spectrometry (AAS) and for As, Se, Sb and Te by atomic absorption spectrometry-hydrid generation (AAS-HG). Only the results of arsenic are discussed in this paper although the survey was extended to all analysed chemical elements. The purpose of this study was to make a risk probability mapping for arsenic that would allow better knowledge about the vulnerability of the soil to arsenic contamination. To achieve this purpose, the initial variable was transformed into an indicator variable using as thresholds the risk-based standards (intervention values) for soils, as proposed by [Swartjes 1999. Risk based assessment of soil and groundwater quality in the Netherlands: Standards and remediation. J. Geochem. Explor.73 1–10]. To account for spatial structure, sample variograms were computed for the main directions of the sampling grid and a spherical model was fitted to each sample variogram (arsenic variable and indicator variables). The parameters of the spherical model fitted to the arsenic variable were used to predict arsenic concentrations at unsampled locations. A risk probability mapping was also done to assess the vulnerability of the soil towards the mining works. The parameters of the spherical model fitted to each indicator variable were used to estimate probabilities of exceeding the corresponding threshold. The use of indicator kriging as an alternative to ordinary kriging for the soil data of Cova dos Mouros produced unbiased probability maps that allowed assessment of the quality of the soil. 相似文献
616.
Thomas C. Edwards Jr. D. Richard Cutler Niklaus E. Zimmermann Linda Geiser Gretchen G. Moisen 《Ecological modelling》2006
We evaluated the effects of probabilistic (hereafter DESIGN) and non-probabilistic (PURPOSIVE) sample surveys on resultant classification tree models for predicting the presence of four lichen species in the Pacific Northwest, USA. Models derived from both survey forms were assessed using an independent data set (EVALUATION). Measures of accuracy as gauged by resubstitution rates were similar for each lichen species irrespective of the underlying sample survey form. Cross-validation estimates of prediction accuracies were lower than resubstitution accuracies for all species and both design types, and in all cases were closer to the true prediction accuracies based on the EVALUATION data set. We argue that greater emphasis should be placed on calculating and reporting cross-validation accuracy rates rather than simple resubstitution accuracy rates. Evaluation of the DESIGN and PURPOSIVE tree models on the EVALUATION data set shows significantly lower prediction accuracy for the PURPOSIVE tree models relative to the DESIGN models, indicating that non-probabilistic sample surveys may generate models with limited predictive capability. These differences were consistent across all four lichen species, with 11 of the 12 possible species and sample survey type comparisons having significantly lower accuracy rates. Some differences in accuracy were as large as 50%. The classification tree structures also differed considerably both among and within the modelled species, depending on the sample survey form. Overlap in the predictor variables selected by the DESIGN and PURPOSIVE tree models ranged from only 20% to 38%, indicating the classification trees fit the two evaluated survey forms on different sets of predictor variables. The magnitude of these differences in predictor variables throws doubt on ecological interpretation derived from prediction models based on non-probabilistic sample surveys. 相似文献
617.
遥感图像上城市震害信息的获取及其应用 总被引:6,自引:0,他引:6
从震害分析和研究的目的出发,讨论了遥感图像资料在城市地震灾害评价中采用的震害信息分类、获取方式、表示方法及应用问题。 相似文献
618.
619.
本文讨论了工业排放含Cu,Pb废水对永丰乡南效村蔬菜地的影响。结果表明:调查地土壤已遭较严重的Cu,Pb合污染。土地壤Cu含量为77.56-1682mg/kg,为对照点的1.6-34倍,所采16个土样中有15个点的土壤Cu含量超过国家标准。土壤中Pb含量为40.5-416mg/kg,为对照点的1.1-11倍。生长于其上的蔬菜已不同程度的受到Cu,Pb的污染。 相似文献
620.
本文对乌江下游沿河到彭水段河水,底质,鱼肉,岩坡土壤和木本植物叶片中汞的含量分布情况作了较全面的调查,结果表明乌江下游沿河至彭水段河水汞含量为0.035-0.05μg/l,底质派含量为131-369μg/kg,鱼肉汞含量为10.5-17.5μg/kg,岸坡土壤汞含量为53.0-2904μg/kg,岩坡木本植物叶片汞含量为18.7-93.5μg/kg,汞含量序为,岸坡封>底质>鱼肉>岸坡木本植物叶>河水。 相似文献