METHOD TO IDENTIFY EFFECTWE RIPARIAN BUFFER WIDTHS FOR ATLANTIC SALMON HABITAT PROTECTION1

ABSTRACT: Successful restoration of declining anadromous species is dependent upon effective riparian buffer zone management. Natural resource managers, policy developers and local conservation groups require science‐based information concerning the width at which a given buffer will be effective for its stated purpose. This paper summarizes a method developed in 1999 to determine effective riparian buffer widths for Atlantic salmon habitat protection as part of the Atlantic Salmon Conservation Plan for Seven Maine Rivers. A major assumption of the method is that no two buffers are alike with respect to their effectiveness and that various buffer characteristics dictate the required width for a given level of effectiveness. The method uses a predictive model that generates suggested riparian buffer widths as a function of specific, measurable buffer characteristics (such as slope, soil characteristics, and plant community structure and density) that affect buffer function. The method utilizes a variable‐width, two‐zone approach and specifies land uses that are consistent with desired buffer function within the two zones.     

Self-help countermeasure strategies for populations living within contaminated areas of Belarus, Russia and Ukraine.

Countermeasures have been effectively employed within intensive agricultural systems in areas of the Former Soviet Union (FSU) affected by the Chernobyl accident. However, ingestion doses continue to be elevated in some areas as a result of few foodstuffs which are collected from the wild or produced by the household. Forest fungi and berries, and milk from privately owned cattle are the most notable contributors to 137Cs intakes amongst these foodstuffs. In this paper we consider advice which would help affected populations to both understand the importance of these exposure routes and to reduce their exposure. In addition to the potential radiological benefits, self-help schemes are highly cost-effective and likely to have a positive psychological influence on populations living within contaminated areas of the FSU. Evidence to suggest that the transfer of radiocaesium to cow milk is considerably higher in the FSU than within western Europe and North America is discussed.     

Latin American busways: moving people rather than cars

The rapid growth of Latin American urban centres beginning in the 1970s placed a heavy strain upon urban transport service providers. Facing high population growth from a citizenry dependent upon public transport and having limited financial resources to develop car‐based infrastructure, Latin American municipal planners were challenged to create a new transport paradigm. One ingenious response to this dilemma was the busway, a surface metro system that utilizes exclusive right‐of‐way bus lanes. The developers of the Latin American busways astutely observed that the ultimate objective was to swiftly, efficiently and cost‐effectively move people rather than cars. Examples of innovative busway systems are presented from Curitiba, Bogota, Porto Alegre, Quito and Sao Paulo. The low cost, flexibility and speed of the exclusive busways all contribute to extremely high levels of customer satisfaction. Innovative approaches to the design of busway loading stations and simplified ticketing have also helped to reduce operating costs and improve customer flows. Additionally, clear system maps, colour‐coded routing, system safety and cleanliness and superior customer service have helped direct consumer preference towards the busway. The success of busways has also proved that costly subway systems or uncontrolled sprawl are not the only options available to municipal planners. The Latin American busway corridors provide high peak capacities that permit busway corridors to serve the transit requirements of most medium‐ to large‐sized cities. When integrated with progressive land‐use policies, busways can also form the basis of more sustainable urban design by encouraging development corridors with high‐density, mixed‐use land use. The environmental benefits and calming influences afforded cities by busway systems have translated into dramatically improved levels of quality of life indicators, including improvements in health, crime reduction and poverty alleviation. The user‐friendliness and cost‐effectiveness of busway systems have convinced municipal leaders in North America, Europe and Australia to develop similar systems of their own. Latin American busways thus provide a unique example of South to North technology transfer.     

新安江水库悬浮颗粒物时空分布、沉降通量及其营养盐效应

为分析降雨入流影响下水库悬浮颗粒物的时空分布及沉降特征,在华东地区最大水库新安江水库(千岛湖)的河流区、过渡区和湖泊区(分别对应街口、小金山和大坝这3个水质断面)布设水体沉降物自动捕获器和水质高频自动监测浮标,结合定期水样采集分析,开展了为期1 a的水体颗粒物沉降通量及其营养盐效应观测研究.结果发现,水库水体浊度、悬浮颗粒物浓度(SS)、颗粒物沉降通量与降雨量、入库流量极显著相关(P0.01),其中浊度与SS的相关性最好(R~2=0.86);在降雨较多的春夏季,SS空间差异明显(河流区过渡区湖泊区),而秋冬空间差异不大;颗粒物沉降通量具有明显的时空异质性,空间上河流区过渡区湖泊区[分别为27.82、 4.34和0.26 g·(m~2·d)~(-1)],时间上春夏季秋冬季;结合全湖60个点位四季悬浮物浓度调查估算,全库颗粒物沉降通量为2.57×10~6 t·a~(-1),其中春夏季沉降通量高于秋冬季;街口、小金山和大坝捕获沉降物中颗粒态氮含量(PN)分别为6 812、 15 886和21 986 mg·kg~(-1),磷含量(PP)分别为2 545、 3 269和3 077 mg·kg~(-1),自上游向下递增.统计分析表明,中雨以上降雨过程与河流区浊度增量呈指数相关(R~2=0.81),持续强降雨则对浊度有累加效应,但对过渡区影响不大;SS浓度自河流入库区至下游大坝随距离增加呈较好的指数下降特征(R~2=0.84),降雨较多的春夏季更为明显.结果还表明,新安江水库年均库容淤损率为0.07%,与全国其它大型水库相比较低,但是坝前沉降物营养盐含量较高,具有一定的内源释放风险;管理上应加强流域水土保持治理,降低降雨冲刷对水质的影响;同时关注坝前高营养沉积物的内源释放对水质的影响.     

新安江水库河口区水质及藻类群落结构高频变化

水库库尾区的水环境多变,是水库生态系统突变的重要策源地.为探究大型水库水源地水环境演变特征及其突变的促发机制,以新安江水库为例,通过库尾河口断面18个月水质浮标的高频记录及3 d一次的藻类群落结构人工鉴定数据等,分析了气象水文过程影响下的水库库尾区的水温、溶解氧、浊度及营养盐等环境指标及藻类群落结构的高频变化特征,揭示了降雨、入流及季节温度变化等关键气象水文过程对水库水质及藻类群落结构的影响机制.结果表明:①在27 m深的河流入库区的水体温度和溶解氧存在明显的季节分层,相应水体藻类叶绿素a和营养盐等指标也同步发生分层,水温分层从气温达到14℃以上的3月中旬开始,至气温降至24℃后的10月中旬结束,期间较大降雨和入流多次破坏水温分层;②河道入库区水体氮、磷等营养盐变幅大,总磷浓度变幅为0. 011～0. 188 mg·L~(-1)之间,总氮浓度变幅为0. 75～2. 76 mg·L~(-1)之间,总磷和总氮中的溶解态占比分别为56%及88%,降雨入流对水体营养盐浓度影响巨大,3 d的累积降雨与水体氮、磷浓度显著正相关,3～6月(雨季)的营养盐含量明显高于其他月份(P 0. 001),藻类的季节性增殖反过来也会影响水体总磷浓度;③藻类群落结构及其优势属呈现明显的季节变化,在总体硅藻门类占优的背景下,蓝藻、绿藻、隐藻等在不同季节形成明显峰值,蓝藻在7～10月的夏秋季形成明显的生物量峰值,其峰值形成原因除了高温之外,还与暴雨入流有关.蓝藻主要优势属为束丝藻属(Aphanizomenon spp.)、微囊藻(Microcystis spp.)及颤藻(Oscillatoria spp.)等,绿藻峰值与蓝藻基本同步,优势属为盘星藻属(Pediastrum spp.)和新月藻属(Closterium spp.),隐藻在3～5月形成峰值,优势属为隐藻属(Cryptomonas spp.),硅藻门中的优势属分别为脆杆藻属(Fragilaria spp.)、小环藻属(Cyclotella spp.)、针杆藻属(Synedra spp.)及直链藻属(Melosira spp.)等;④入库流量、温度、水位、透明度、总氮、总磷及氮磷比等均为影响藻类优势属演替的主要因子,秋冬季节的控制因子为气象水文条件,而夏秋季节则受气象水文及营养盐的共同控制.本研究表明强降雨过程能对水库库尾区水环境及水生态系统结构产生巨大冲击,是水库藻类水华发生的可能诱发因子,通过对该过程的规律认识及关键指标监测,能够为水库水源地水质风险提供预警信息.     

Best‐practice recommendations for estimating interaction effects using meta‐analysis

One of the key advantages of meta‐analysis (i.e., a quantitative literature review) over a narrative literature review is that it allows for formal tests of interaction effects—namely, whether the relationship between two variables is contingent upon the value of another (moderator) variable. Interaction effects play a central role in organizational science research because they highlight boundary conditions of a theory: Conditions under which relationships change in strength and/or direction. This article describes procedures for estimating interaction effects using meta‐analysis, distills the technical literature for a general readership of organizational science researchers, and includes specific best‐practice recommendations regarding actions researchers can take before and after data collection to improve the accuracy of substantive conclusions regarding interaction effects investigated meta‐analytically. Copyright © 2010 John Wiley & Sons, Ltd.     

Worst case scenario study to assess the environmental impact of amine emissions from a CO2 capture plant

Use of amines is one of the leading technologies for post-combustion carbon dioxide capture from gas and coal-fired power plants. This study assesses the potential environmental impact of emissions to air that result from use of monoethanol amine (MEA) as an absorption solvent for the capture of carbon dioxide (CO₂). Depending on operation conditions and installed reduction technology, emissions of MEA to the air due to solvent volatility losses are expected to be in the range of 0.01–0.8 kg/tonne CO₂ captured. Literature data for human and environmental toxicity, together with atmospheric dispersion model calculations, were used to derive maximum tolerable emissions of amines from CO₂ capture. To reflect operating conditions with typical and with elevated emissions, we defined a scenario MEA-LOW, with emissions of 40 t/year MEA and 5 t/year diethyl amine (DEYA), and a scenario MEA-HIGH, with emissions of 80 t/year MEA and 15 t/year DEYA. Maximum MEA deposition fluxes would exceed toxicity limits for aquatic organisms by about a factor of 3–7 depending on the scenario. Due to the formation of nitrosamines and nitramines, the estimated emissions of DEYA are close to or exceed safety limits for drinking water and aquatic ecosystems. The “worst case” scenario approach to determine maximum tolerable emissions of MEA and other amines is in particular useful when both expected environmental loads and the toxic effects are associated with high uncertainties.     

离子色谱法测定环境空气中氯化氢时应注意的问题

用离子色谱法测定大气中低浓度氯化氢,方法灵敏、准确度高,但测定过程极易受污染干扰.本文主要探讨了在前期准备、采样和分析全过程中应注意的一些问题.     

Home energy efficiency grants and advice: findings from the English Midlands

Research was conducted in Nottinghamshire, England to investigate public attitudes regarding home energy efficiency issues. Quantitative data were collected in the form of a postal survey, achieving over three hundred responses. Additionally, predominantly qualitative data were collected in semi-structured interviews in 15 homes. The issues investigated included the grant-funded energy efficiency measures installed by the public, the organisations providing grants, the means by which the recipients were referred to the organisations, and the public's preferences regarding energy efficiency advice. Findings were made about the local authority's success in encouraging the take-up of energy efficiency grants, about the public's preferences for the means by which advice should be provided, about trust relating to energy efficiency grants provided by gas and electricity suppliers, and about people's knowledge of the most effective energy efficiency measures. Additional findings were drawn about specific energy efficiency issues, including old heating systems and compact fluorescent light bulbs.