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湖南省酸雨现状与成因分析 总被引:1,自引:0,他引:1
湖南省是地处中南的酸雨污染严重区域。本文依据湖南省1993—1999年监测酸雨的数据资料,对湖南省酸雨的现状特征作了简要的阐述,对湖南省酸雨的成因进行了较为系统的分析,并对酸雨的发展趋势进行了预测,初步提出了一些酸雨防治对策。 相似文献
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中国南方酸雨的分布特征及其成因分析 总被引:4,自引:0,他引:4
本文阐述了酸雨的危害、近几年中国南方地区酸雨的污染的时空分布状况、酸雨的成因等3方面的内容。研究表明:我国南方酸雨区的酸雨污染状况基本上处在一个稳定的时期。降水pH〈5的区域有从长江中上游向长江中下游发展的趋势;在时间分布上,秋季冬季降水pH低,酸雨发生的频率高;春季夏季降水pH高,酸雨发生的频率低。在酸雨的成因上,着重讨论了大气性质、污染物的迁移和扩散、气候条件、大气中颗粒物浓度以及土壤性质对酸雨形成的影响。 相似文献
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为掌握我国酸雨污染现状和发展趋势,确定我国酸雨污染区域和污染程度,核查我国酸雨污染的主要污染组分和特征,为更好地控制酸雨污染提供依据,安徽省17个省辖市分别于2002年、2004~2005年参加了为期3年的酸雨普查工作。安徽省酸雨频率分布与变化普查期间,安徽省出现酸雨的城市在10个左右,主要出现在长江以南及江淮之间中、东部,淮河以北及江淮之间西部基本无酸雨。全省酸雨频率大于5%的地区主要分布在安徽的中、南部区域,主要包括合肥、蚌埠、滁州、宣城、铜陵、池州、黄山等市,面积约5.87万平方公里,占全省国土面积的42%。安徽省酸雨频率大… 相似文献
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依据山东省多年来的降水观测资料,评价了酸雨污染现状,研究了酸雨时空分布规律.通过对主要酸雨前体物的排放强度与降水酸度的关系,土壤酸碱性与降水酸度的关系,以及气象条件对酸雨影响的分析,探讨了山东省酸雨的成因. 相似文献
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本文对2006年泸州市的酸雨污染状况,以及降水中阴、阳离子成分进行了分析,为确定泸州市酸雨污染原因和酸雨类型提供了依据,并对降低酸雨污染提出了控制措施。 相似文献
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近年酸雨监测数据表明,四川已出现大面积的酸雨区。为了解和评价目前酸雨对四川水体的影响,我们测定了自贡市荣县、宜宾市郊和南充县三个重酸雨区内非 相似文献
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Donald L. Chery Calvin G. Clyde Roger E. Smith 《Journal of the American Water Resources Association》1979,15(4):1126-1145
ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m2) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft3/sec (0.085 to 3.34 m3/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes. 相似文献
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A. U. Mallik 《Environmental management》1995,19(5):675-684
Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into
heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil
acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed
habitats.
If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged
unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest
vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation
shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation. 相似文献
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Carl J. Sindermann 《Journal of the American Water Resources Association》1988,24(5):931-939
ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities. 相似文献
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Pickett ST Cadenasso ML Grove JM Boone CG Groffman PM Irwin E Kaushal SS Marshall V McGrath BP Nilon CH Pouyat RV Szlavecz K Troy A Warren P 《Journal of environmental management》2011,92(3):331-362
Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs. 相似文献
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Justin D. Burdine 《Local Environment》2018,23(2):198-219
Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered. 相似文献
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All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by
outside sources. However, much of the previous research on agricultural information has concentrated on what information various
media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few
studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural
journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover
agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial
copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being
in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy.
Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work,
and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who
cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel
study. 相似文献
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Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences
in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental
classifications of the streams and rivers of France that had been defined from the same environmental data using geographic
regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages,
water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by
analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables
and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a
given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a
posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions.
The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly
better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using
different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and
that alleged differences in performance arising from different classification procedures can be small relative to unexplained
variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental
classifications and decisions over which procedures to use should be based primarily on pragmatic considerations. 相似文献
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Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions. 相似文献
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Kathryn Paxton George 《Journal of Agricultural and Environmental Ethics》1988,1(3):175-192
The maintenance of biodiversity is urged from many quarters and on grounds ranging from aesthetic considerations to its usefulness, particularly for biotechnology. But regardless of the grounds for preserving biodiversity, writers are generally in agreement that it should be preserved. But, in examining the various references biodiversity, such as species diversity, genetic diversity, and habitat diversity, it is apparent that we cannot aim to preserve biodiversityas such, since there are a number of conflicts in any such undertaking. In preserving one aspect of biodiversity, we damage another aspect. Five arguments which attempt to ground our moral concern for biodiversity are reviewed and critiqued, not only for their consistency but also for their power to move us to action. The final section of the paper shows how conflicts in the values of personal and environmental health can impair ethical action and especially policy formation.An earlier version of this paper was read at the conference on Agriculture, Food, and Human Values: Tradition and Change, Orlando, Florida, October 7–9, 1987. 相似文献
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Donald M. Bruce 《Journal of Agricultural and Environmental Ethics》2002,15(3):279-289
Future technological developmentsconcerning food, agriculture, and theenvironment face a gulf of social legitimationfrom a skeptical public and media, in the wakeof the crises of BSE, GM food, and foot andmouth disease in the UK (House of Lords, 2000). Keyethical issues were ignored by the bioindustry,regulators, and the Government, leaving alegacy of distrust. The paper examinesagricultural biotechnology in terms of a socialcontract, whose conditions would have to be fulfilled togain acceptance of novel applications. Variouscurrent and future GM applications areevaluated against these conditions. Successwould depend critically on how far a sharedvision can be found with the public. Tore-establish trust, significant changes areidentified in the planning and pursuit ofbiotechnology. 相似文献