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81.
热污染及其防治   总被引:6,自引:1,他引:5  
对热污染状况进行了介绍.概括了热污染的危害,包括危害人体健康、影响全球气候变化、污染大气、污染水体、加快水分蒸发、增加能量消耗等.分析了热污染的原因,自然气候的异常变化和人为因素是热污染产生的两大原因.最后提出了几点防治热污染的措施.  相似文献   
82.
生命周期评价理论与方法作为一种量化环境影响的工具,在诸多领域中得到了广泛的应用。在垃圾处理领域,生命周期评价最早在20世纪90年代得到应用。生命周期评价与城市生活垃圾处理的有效结合,将促进城市生活垃圾的减量化、资源化、无害化目标的实现。总结了生命周期评价理论与方法在城市生活垃圾处理中的应用现状。对国内不同城市生活垃圾处理方式环境影响因子进行比较分析,诸如全球变暖潜力、酸化潜力和富营养化潜力等因子。针对其目标范围定义、数据收集、评价方法的选择、结果解释及工艺改进等方面指出了目前研究的局限性和不足。并对未来城市生活垃圾处理生命周期评价的发展方向进行展望。  相似文献   
83.
Abstract:  Although it is known that changes in land use and climate have an impact on ecological communities, it is unclear which of these factors is currently most important. We sought to determine the influence of land-use and climate alteration on changes in the abundance of Central European birds. We examined the impact of these factors by contrasting abundance changes of birds of different breeding habitat, latitudinal distribution, and migratory behavior. We examined data from the semiquantitative Breeding Bird Atlas of Lake Constance, which borders Germany, Switzerland, and Austria. Changes in the regional abundance of the 159 coexisting bird species from 1980–1981 to 2000–2002 were influenced by all three factors. Farmland birds, species with northerly ranges, and long-distance migrants declined, and wetland birds and species with southerly ranges increased in abundance. A separate analysis of the two decades between 1980–1981 and 1990–1992 and between 1990–1992 and 2000–2002 showed that the impact of climate change increased significantly over time. Latitudinal distribution was not significant in the first decade and became the most significant predictor of abundance changes in the second decade. Although the spatial scale and temporal resolution of our study is limited, this is the first study that suggests that climate change has overtaken land-use modification in determining population trends of Central European birds.  相似文献   
84.
Effects of Widespread Fish Introductions on Paedomorphic Newts in Europe   总被引:4,自引:0,他引:4  
Abstract:  As a result of factors such as global warming, habitat destruction, and species introduction, amphibians are declining worldwide. No one, however, has analyzed the status of polymorphic amphibian species at a national or continental scale, although some local reports exist. Our aim was to report on the loss of intraspecific heterochrony as a loss to diversity in determining the consequences of fish stocking on European populations of paedomorphic newts. Paedomorphosis is a polymorphism in which larval traits are retained in the adult stage. We surveyed 39 paedomorphic populations of the alpine (  Triturus alpestris ) and palmate ( T. helveticus ) newts, all but one of which initially occupied fishless ponds and lakes in France, Italy, Slovenia, Bosnia, Montenegro, and Greece. Exotic fishes were found in 44% of the studied aquatic habitats, with a 100% presence in Montenegro. At all sites paedomorphs disappeared and metamorphs declined. Only fish explained these population changes because alternative factors such as drying were not significant. More catastrophically, fish introductions occurred in habitats known to support the largest populations of newts and even some endemic subspecies. If management and legislative measures are not taken to stop fish stocking, protect paedomorphs as conservation units at national and international levels, and restore natural habitats, all the largest paedomorphic populations may disappear in the near future. Their disappearance would represent a loss of one of the rare, fascinating examples of intraspecific heterochrony.  相似文献   
85.
由于大量人类活动的影响,大气CO_2浓度持续增加,其中约1/3被海洋吸收,导致表层海水pH值降低和碳酸盐平衡体系波动,即"海洋酸化"现象。污染物的海洋环境效应一直是全球环境科学领域研究的热点。在实际环境中,海洋酸化往往与污染物共同存在并作用于海洋生态系统,且海洋酸化极有可能改变污染物的海洋环境行为从而影响其毒性效应。但现有研究大多针对海洋酸化或者污染物单独作用下的毒性效应展开,对海洋酸化与污染物的联合毒性效应的研究不足、亟待加强。为此,综述了近年来海洋酸化与典型污染物(重金属、有机污染物)及新型污染物(人工纳米颗粒)的相关文献,重点阐述了海洋酸化对污染物环境行为的影响和海洋酸化与污染物对海洋生物的联合毒性效应,指出当前的研究不足,并对未来的研究方向进行了展望。  相似文献   
86.
土地利用和土地覆盖变化研究模型综述   总被引:112,自引:6,他引:112  
本文综述了全球变化研究中土地利用和土地覆盖变化(LUCC)的主要模型,重点介绍了植被模型和引入社会驱动力的LUCC模型,并归纳出LUCC模型的以下发展趋势:①新一代的LUCC模型应该能够模拟LUCC的主要社会经济和自然驱动力,包括从LUCC到驱动力和全球变化的主要反馈关系;②具有明确的空间关系,能够以适当的空间分辨率,比较好地预测长期的(50~100a)土地利用和覆盖变化及有关的生物物理参数,如植被特征、资源的积聚和退化等;③能够更好地认识LUCC与其主要驱动力之间的关系在局地、区域和全球尺度上的动态和后果;充分考虑土地利用和覆盖变化对政策、技术进步、人口增长、经济发展、市场变化等社会变量的灵敏性,此外,还应注意意识、信仰等文化因素的影响;④发展新的LUCC建模方法,使LUCC模型能够与其它类型的全球变化模型,特别是气候模型建立联系。  相似文献   
87.
Many proposed activities formitigating global warming in the land-use change and forestry(LUCF) sector differ from measures to avoid fossilfuel emissions because carbon (C) may be held out ofthe atmosphere only temporarily. In addition, thetiming of the effects is usually different. Many LUCFactivities alter C fluxes to and from the atmosphereseveral decades into the future, whereas fossil fuelemissions avoidance has immediate effects. Non-CO2 greenhouse gases (GHGs), which are animportant part of emissions from deforestation inlow-latitude regions, also pose complications forcomparisons between fossil fuel and LUCF, since themechanism generally used to compare these gases(global warming potentials) assumes simultaneousemissions. A common numeraire is needed to expressglobal warming mitigation benefits of different kindsof projects, such as fossil fuel emissions reduction,C sequestration in forest plantations, avoideddeforestation by creating protected areas and throughpolicy changes to slow rates of land-use changes suchas clearing. Megagram (Mg)-year (also known as`ton-year') accounting provides a mechanism forexpressing the benefits of activities such as these ona consistent basis. One can calculate the atmosphericload of each GHG that will be present in each year,expressed as C in the form of CO2 and itsinstantaneous impact equivalent contributed by othergases. The atmospheric load of CO2-equivalent Cpresent over a time horizon is a possible indicator ofthe climatic impact of the emission that placed thisload in the atmosphere. Conversely, this index alsoprovides a measure of the benefit of notproducing the emission. One accounting methodcompares sequestered CO2 in trees with theCO2 that would be in the atmosphere had thesequestration project not been undertaken, whileanother method (used in this paper) compares theatmospheric load of C (or equivalent in non-CO2GHGs) in both project and no-project scenarios.Time preference, expressed by means of a discount rateon C, can be applied to Mg-year equivalencecalculations to allow societal decisions regarding thevalue of time to be integrated into the system forcalculating global warming impacts and benefits. Giving a high value to time, either by raising thediscount rate or by shortening the time horizon,increases the value attributed to temporarysequestration (such as many forest plantationprojects). A high value for time also favorsmitigation measures that have rapid effects (such asslowing deforestation rates) as compared to measuresthat only affect emissions years in the future (suchas creating protected areas in countries with largeareas of remaining forest). Decisions on temporalissues will guide mitigation efforts towards optionsthat may or may not be desirable on the basis ofsocial and environmental effects in spheres other thanglobal warming. How sustainable development criteriaare incorporated into the approval and creditingsystems for activities under the Kyoto Protocol willdetermine the overall environmental and social impactsof pending decisions on temporal issues.  相似文献   
88.
海洋原位化学探测核心技术的研究应用   总被引:3,自引:0,他引:3  
化学传感器和化学分析器是海洋原位化学探测系统中的核心技术。本文从电化学、光纤化学和湿法化学分析等三个领域介绍了国际上化学传感器和化学分析器的研究和应用现状 ,比较了部分化学传感器和化学分析器的性能指标和优缺点 ,指出了海洋原位化学探测技术的发展趋势。与国外海洋原位化学探测技术的研究相比 ,我国在这方面的研究基本上还是空白 ,海洋原位化学探测技术已成为我国亟待发展的海洋高新技术之一。  相似文献   
89.
糖蜜酒精废水厌氧可生化性实验研究   总被引:2,自引:0,他引:2  
采用自制的球形反应器对糖蜜酒精废水进行厌氧可生化性研究.实验持续了40 d,CODcr从38 652 mg·L-1下降到6 094 mg·L-1,总去除率达84.23%.说明糖蜜酒精废水的厌氧可生化性较好;硫酸盐浓度由最初的3 860 mg·L-1下降到470 mg·L-1,去除率为87.82%.同时,有机污染物的去除高峰期比其硫酸盐延迟了2~4 d,说明可以通过控制运行反应条件和参数,对该废水采用两相厌氧处理工艺,在产酸相提前去除大部分的硫酸盐,减弱高浓度硫酸盐对厌氧反应的抑制作用.  相似文献   
90.
通过调查温州滨海地区近岸海上渔业、航运码头、滨海旅游及餐饮业等行业塑料垃圾的排放,分析行业区域塑料垃圾赋存特征,并初步估算各行业塑料垃圾排放量.结果表明:海上渔业活动区中,以避风塘渔港(S4)塑料垃圾占比最高(91.68%),且以聚乙烯、聚苯乙烯和聚丙烯塑料为主,而东沙渔港(S2)和霞关海水养殖区(S6)以聚苯乙烯泡沫为主,占比分别为26.75%和23.66%.海滩餐饮活动区的塑料垃圾最少,塑料垃圾占比为33.13%.各活动区塑料垃圾的主要类型有塑料袋、塑料瓶、塑料盒、塑料管及破碎的塑料块.据估算,海上渔业活动区与滨海旅游区年排放塑料垃圾量约为1.21×104t/a.为从根本上防治海洋塑料垃圾和海洋微塑料污染,需首先对沿海各行业的塑料垃圾排放源头加强管理,如海水养殖与海洋捕捞活动.  相似文献   
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