Long-Term Variability in Bioassessments: A Twenty-Year Study from Two Northern California Streams

Long-term variability of bioassessments has not been well evaluated. We analyzed a 20-year data set (1984–2003) from four sites in two northern California streams to examine the variability of bioassessment indices (two multivariate RIVPACS-type O/E scores and one multimetric index of biotic integrity, IBI), as well as eight metrics. All sites were sampled in spring; one site was also sampled in summer. Variability among years was high for most metrics (coefficients of variation, CVs ranging from 16% to 246% in spring) but lower for indices (CVs of 22–26% for the IBI and 21–32% for O/E scores in spring), which resulted in inconsistent assessments of biological condition. Variance components analysis showed that the time component explained variability in all metrics and indices, ranging from 5% to 35% of total variance explained. The site component was large (i.e., >40%) for some metrics (e.g., EPT richness), but nearly absent from others (e.g., Diptera richness). Seasonal analysis at one site showed that variability among seasons was small for some metrics or indices (e.g., Coleoptera richness), but large for others (e.g., EPT richness, O/E scores). Climatic variables did not show consistent trends across all metrics, although several were related to the El Ni?o Southern Oscillation Index at some sites. Bioassessments should incorporate temporal variability during index calibration or include climatic variability as predictive variables to improve accuracy and precision. In addition, these approaches may help managers anticipate alterations in reference streams caused by global climate change and high climatic variability.     

Avian sensitivity to mortality: Prioritising migratory bird species for assessment at proposed wind farms

Wind power generation is likely to constitute one of the most extensive human physical exploitation activities of European marine areas in the near future. The many millions of migrating birds that pass these man-made obstacles are protected by international obligations and the subject of public concerns. Yet some bird species are more sensitive to bird–wind turbine mortality than others. This study developed a simple and logical framework for ranking bird species with regard to their relative sensitivity to bird–wind turbine-collisions, and applied it to a data set comprising 38 avian migrant species at the Nysted offshore wind farm in Denmark. Two indicators were selected to characterize the sensitivity of each individual species: 1) relative abundance and 2) demographic sensitivity (elasticity of population growth rate to changes in adult survival). In the case-study from the Nysted offshore wind farm, birds of prey and waterbirds dominated the group of high priority species and only passerines showed a low risk of being impacted by the wind farm. Even where passerines might be present in very high numbers, they often represent insignificant segments of huge reference populations that, from a demographic point of view, are relatively insensitive to wind farm-related adult mortality. It will always be important to focus attention and direct the resources towards the most sensitive species to ensure cost-effective environmental assessments in the future, and in general, this novel index seems capable of identifying the species that are at high risk of being adversely affected by wind farms.     

环境工艺方法论研究——移植嫁接法

移植嫁接法是环境工艺创新中的一种重要方法。本文从环境工艺的角度阐述了移植嫁接法的定义,从学科方法和自然过程移植两方面枚举了该法在环境工艺中的应用成果,在此基础上探讨了移植嫁接法中丰富的哲学内涵。     

Measuring populations' vulnerabilities for famine and food security interventions: the case of Ethiopia's Chronic Vulnerability Index

The concept of vulnerability has become an important part of food security analyses since the 1980s. It is seen as having two sides: exposure to external hazards; and an inability to cope with those shocks, attributed to social, political, and economic factors. Numerous attempts have been made to construct models to determine levels of vulnerability among populations. This paper analyses one such attempt, the Chronic Vulnerability Index (CVI), developed to measure levels of vulnerability to food insecurity in Ethiopia. The example of the CVI reveals many of the difficulties associated with producing a basic model of vulnerability that can be used in disaster mitigation. Ultimately, the CVI assumes that vulnerability is a linear, additive phenomenon with discrete causes and effects and fails to capture interactions between hazards and the human systems that produce and complicate them. The paper concludes with a discussion of alternatives to the CVI.     

室内空气质量指数评价模式的研究

提出室内空气质量的三级评价标准和五个评价等级,建议依据评价目的,选择相应污染物质作为评价因子。分析常用指数评价模式的特点,建立适用于室内空气质量评价的综合指数模式,该模式是一种客观有效的评价方法。     

湖北省各主要地市水资源压力指数评价

以湖北省为研究区域,在前人研究基础上,从人口数量压力、水资源数量压力、水环境压力、水资源技术压力、水资源经济压力和水资源紧缺压力6个角度对2009年湖北省各主要地市的水资源压力指数进行了计算和分析。结果表明:湖北省内,武汉市水资源压力最大,鄂州次之,宜昌和黄石市等水资源压力相对较大,黄冈、荆州和十堰市等水资源压力相对较小;武汉市的人口数量压力和水资源紧缺压力大,鄂州市的水资源数量压力大,宜昌和十堰的水环境压力大,随州和黄冈市的水资源技术压力大,孝感市水资源经济压力较大。     

土壤样品中汞消解方法探讨

在使用ZYG—Ⅱ型智能冷原子荧光测汞仪测定土壤样品时,发现消解液中的盐酸试剂含有微量汞,使土壤中痕量汞的测定无法进行,本文采用巯基棉纤维提纯盐酸试剂并通过标准土样的测定对方法的准确度进行了验证。     

大头小杆形凸肩齿轮胎模锻的合理方法

从锻造工艺技术角度,讨论了提高大头小杆或大头细杆凸肩齿轮锻件的内在质量和有利于锻件成形胎模锻的合理方法.同时介绍了拔镦法、镦拔法、镦挤法和镦拔挤复合法胎模锻的适用范围、原材料规格与中间坯料形状尺寸的确定原则和胎模的设计原则,及其应用实例.     

辽阳市汤河水库饮用水源水质现状分析及污染防治对策

通过对辽阳市汤河水库饮用水源的现状分析,确定了污染原因,提出保护地表水饮用水源的对策。     

秦岭安河矿区地表水、沉积物重金属污染研究

以秦岭安河铅锌矿开采区和选矿区为研究范围,通过现场调查和系统采集地表水、沉积物样品,借助原子吸收分光光度计测试样品中Cu、Pb、Zn、Cd、Cr 5种重金属全量,并对不同重金属的形态含量进行了测定,综合分析了各类重金属在地表水、沉积物中的富集迁移规律,实现了重金属污染程度的综合评价。结果表明:矿区沟道地表水、沉积物已受到严重的重金属污染,重金属元素自上游到下游呈累积现象。下游地表水重金属含量超出农田灌溉用水水质要求。中游、下游沉积物重金属污染指数达到Ⅲ级污染,主要污染物为Pb、Zn。沉积物中重金属的有效态所占比例较高,对周围环境直接威胁大,显示出外源重金属直接注入的特征。