港口工程对沿海环境的影响

海洋的许多生态参数,如溶解氧浓度和温度等均与环流有关,所以环流的流态对海洋环境的影响十分显著。在海中建造各种建筑物必然会妨碍水体运动,从而影响海洋环境。本文旨在研究港口建筑物对环流运动的影响和由此而引起的环境影响。 文中提出一个可供估算水文参数和废水耗氧量变化的简易数学模型。对于废水引起的富营养化效应也做了分析研究。 在港口工程规划设计阶段,必须进行环境生态影响的研究,如果港口附近有污水排放口,进行环境影响分析尤为重要。 本文介绍的方法,曾应用于靠近雅典城市污水排放区的比雷埃夫斯港的扩建工程。分析表明,如果按照原来的设计进行施工,而忽视工程引起的环境影响,其结果必然导致明显的生态变化。     

自由市场与环境

在诺贝尔奖得主保罗·塞缪尔森首先提出的经济理论中,有这样一种见解,即不能指望不受控制的市场会保护环境。按照这一理论,清洁的空气和水属于“公共消费品”,其价值在市场过程中是得不到充分反映的。那些可能制造污染的人不会考虑他们行为的社会成本,而只关心自身承担的成本;此外,由于清洁环境的工作甚至可以使那些袖手旁观者也蒙受其益,如此一来,人人都会自然而然地想坐享其成。同样,如果市场不能立竿见影地反映出保存多样化生物或拯救具体物种的利益,土地拥有者也不会愿意为公益而出钱保护环境。这一理论认为,如果没有政府干预,环境就得不到充分保护。     

库里提巴市的可持续性与规划程序

可持续性是一个关于人与自然或社会与环境平衡的概念。根据自身历史、地理或社会文化背景的不同，每个人或社会对这一概念的理解也不相同。虽然在理论上缺乏一致性，但是可持续发展概念一直存在于社会的自然与人为空间适应和变化过程中，以及以生存和发展为目的的生产过程中。当涉及到城市或城市空间时，这些过程反映了一个社会认可、支配和确定保证满足基本需求范围的方式，同时确保城市随着时间的发展而生存下来。     

底辟作用和重力构造会议

<正> 引言自 H.Ramberg(1963)在实验室开始他的著名的模拟底辟构造研究,并将这些模拟研究应用于解释造山带主要构造的成因以来,至今将近二十年了。在此期间,构造地质学思想发生了一场革命,即基于地球板块构造运动的水平构造的思想比与底辟有关的垂直构造的思想来说占优势地位。因此考虑,应及时地回顾一下底辟作用在区域变形中的相对作用,于是构造研究组(隶属伦敦地质学会)于1980年3月25-     

青年决定环保公众参与的未来

环境问题的产生很大程度上是过度消费导致的。青年是社会的未来。青年能否 转换消费观念,树立绿色消费模式,积极投身保护环境,直接决定了未来社会 的发展。     

The role of socio-economic data in food needs assessment and monitoring

This paper reviews six case studies examined as part of a project to review targetting methodologies employed by non-government organisations in Africa during the 1984-6 food crisis. Most agencies have not yet fully evaluated the role of data in informing policy decisions during their respective emergency programmes. The case studies presented reflect a wide variety of approaches to targetting emergency food aid that are based largely on the use of 'socio-economic' data. The recent emergency relief operations in Africa seem to indicate a change in relief agencies' approaches to the assessment and monitoring of needs of the affected populations. Earlier dependance on nutritional data has given way to an increasing reliance on the use of socio-economic indicators. There was a wide variation in the case studies of the type of indicators collected and utilised in needs assessment and monitoring. There were those who relied almost exclusively on nutritional data to target resources during the 1984-86 African crisis, and others whose experiences during that period lead them to attach more weight to socio-economic data. Other agencies appear to have recognised the problems of relying solely on nutritional data to target food aid during their 1984–86 emergency programmes, and thus more or less abandoned classical anthropometric surveys in their needs assessment and monitoring methodologies during this period. Thus nutritional data has a less significant role in the decision making process than previously had been the case.     

Effect of nickel on some aspects of protein metabolism in the gill and kidney of the freshwater fish, Cyprinus carpio L

Nickel has an adverse effect on some aspects of protein metabolism of the freshwater fish, Cyprinus carpio. The main changes observed were: (a) Decrease in soluble, structural and total proteins, AlAT and AAT activities with an increase in the levels of free amino acids, protease and GDH activities and ammonia in the gill and kidney at 1, 2, 3, and 4 days of exposure to a lethal concentration, 40 mg litre(-1) of nickel; (b) Increase in soluble, structural and total proteins, free amino acids and the activities of protease, AlAT, AAT and GDH with a decrease in ammonia and urea in these organs at 1, 5, 10 and 15 days of exposure to sublethal concentration, 8 mg litre(-1); (c) The magnitude in these changes increased over time with both concentrations of the metal, and was more marked in gill than in kidney.     

The response of stream-dwelling fish to liming

The fish fauna in 22 limed and seven unlimed small streams was monitored using yearly electrofishing to assess the effects of liming on species occurrence and abundance. The liming techniques were divided into three main methods, lake liming, doser liming and wetland liming, to evaluate whether different strategies had different effects on the fish fauna. The predominant species at the investigated stations were salmonids, mainly brown trout (Salmo trutta) and Atlantic salmon (Salmo salar). Other species generally occurred in low numbers. The average number of fish species did not increase significantly after liming, which was probably due to recolonization difficulties caused by the frequent occurrence of migration obstacles in the streams. After liming the density of salmonids increased significantly, irrespective of the liming method. Other fish species showed no general increase, but in individual streams significant increases of European minnow (Phoxinus phoxinus) and bullhead (Cottus gobio) occurred. Some unlimed streams had acid spates with a pH below 6, which immediately lowered the numbers of salmonid parr. Other unlimed streams lost fish species progressively due to increasing acidification. pH, and probably increased levels of metals, were the major factors regulating the fish fauna. Few examples of biotic interactions were observed, but with an increase of Atlantic salmon parr after liming, brown trout abundances decreased in three streams.     

Contribution of canopy leaching to sulphate deposition in a Scots pine forest

Radioactive sulphate (35SO4) was applied to the soil below a Scots pine forest on 23 June 1989, and its movement into the canopy and into throughfall and stemflow was measured over 4 months. The specific activity, Bq (mg S)(-1), of the canopy increased monotonically; uptake by current-year (1989) expanding needles was initially twice as fast as by older needles or live twigs. By 10 October the canopy average specific activity was 62 Bq (mg S)(-1). The specific activity of net throughfall (throughfall + stemflow - rain), deduced from measurements from six throughfall collectors, six stemflow collectors and two rain collectors, fell rapidly from 12.6 Bq (mg S)(-1) in late July to <1 Bq (mg S)(-1) in mid-August. The results suggest (assuming rapid equilibration of 35S with sulphate in soil) that root-derived sulphate contributed c. 3% of sulphate in net throughfall and that dry deposition of SO2 and sulphate particles contributed c. 97% of the 0.56 g S m(-2) measured in net throughfall over the period. Simultaneous measurements of SO2 at canopy height and of NH3 above and within the canopy gave mean concentrations of 5.9 and 0.86 microg m(-3), respectively, sufficient to account for the sulphate measured in net throughfall only if codeposition of NH3 and SO2 occurred to canopy surfaces. The large values of specific activity observed in July, however, indicate that throughfall composition may be closely related to recent soil input of sulphate, and that equilibrium cannot be safely assumed. The possibility of a significant contribution of soil-derived sulphate to sulphate deposition in net throughfall cannot be ruled out on the basis of this experiment.     

Factors affecting trace-metal bioaccumulation in Finnish headwater lakes

Fourteen unpolluted Finnish headwater lakes with pH values varying from 4.8 to 7.0 were studied for trace-metal concentrations in water, sediment, aquatic plants (Nuphar luteum L., Sparganium sp.), aquatic insect larvae (Limnophilus sp., Phryganea sp.) and fish (Esox lucius L., Perca fluviatilis L., Coregonus sp., Salvelinus fontinalis L., Salmo trutta L.). Trace-metal deposition was estimated by analysing the snowpack. Non-parametric correlation analysis was carried out between trace metal concentrations in biota and pH, ANC, TOC, CA + Mg concentration in water and a given metal concentration in water and sediment. Bioaccumulation of several trace metals increased with increasing acidity and decreasing ANC in water. This was especially true for Pb and Cd. Aquatic plants were, in general, the best indicator group concerning differences in trace-metal bioaccumulation in lakes with different acidity. There was some evidence that a higher concentration of TOC in water may reduce bioaccumulation of Pb, Cd and Zn in aquatic plants and fish. The copper concentration in sediment was the only background variable explaining Cu concentration in aquatic insects. Multivariate analysis of the whole background data gave comparable preliminary results. Over 80% of the trace metal concentrations in biota of different lakes was explained by the background variables. In general, elevated concentrations of most of these trace metals can be expected to occur in the biota of acidified low calcareous lakes.