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91.
92.
This paper assesses the Bluff oyster fishery in New Zealand as a case study in common pool resource management. It discusses ways in which modern information technology, augmented by low-tech data gathering strategies and community ethnography, can be used to produce an integrated scientific and local knowledge-inspired fishery database that lends itself to fostering collaboration in resource management and planning. The specific context and state of the oyster fishery in Bluff are described. Issues regarding undocumented and ephemeral intergenerational knowledge, much of which is geospatial in nature, on the fishery, the current crisis that many see in the future of the fishery, and a lack of cohesion or common sense of purpose between the stakeholder groups are discussed. It is argued that the digital resource that results from the integration of local and scientific knowledge and the potential community building processes that can ensue from collaboration and dialogue around this centrepiece are of central importance in developing an oyster fishery management plan that is holistic in concept and sustainable in purpose.  相似文献   
93.
As the nations of the world negotiate future controls on greenhouse gas emissions, a critical environmental policy issue becomes understanding the multiple environmental consequences of these controls. Here we describe an integrated assessment model for quantifying multiple environmental impacts of large-scale environmental initiatives and apply this model to climate change mitigation. Our analysis shows that reductions in global warming will be accompanied by reductions in ozone depletion, acid rain and mercury emissions, and desulfurization waste generation. We also conclude that the largest collateral benefits from reducing global climate change may be in the developing world. This result is critical since it is the developing nations who ultimately control the long-term success of any climate stabilization strategy. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
94.
Australian approaches to coastal vulnerability assessment   总被引:2,自引:1,他引:1  
The Australian coastline is one of the longest and most diverse of any in the world, and Australian researchers have developed preliminary models of the behaviour of major coastal systems such as beaches and reefs. The Australian population is particularly focused along the coastline, especially in metropolitan centres; however, the population of regional centres along the coast is increasing steadily in response to a phenomenon termed seachange. Coastal systems are increasingly threatened by potential impacts as a result of climate change, as indicated by the successive assessments by the Intergovernmental Panel on Climate Change (IPCC). Although Australia played a central role in applying a common methodology (CM), developed from IPCC guidelines in the 1990s, and in devising alternative approaches, which were initially trialled at nine sites on the Australian coast, there has not been a nationally co-ordinated approach to assessing the coastal vulnerability of Australia, and such an approach is only emerging now. Instead, there have been a series of different approaches adopted to look at the different parts of the Australian coast, including wetland mapping in northern Australia; geomorphic unit mapping in South Australia; storm surge vulnerability modelling in Queensland; probabilistic approaches to beach erosion in New South Wales; indicative mapping of potential coastal retreat in Tasmania. Additionally, there have been methods proposed by insurers and coastal engineers to meet their requirements. Since 2005, the Australian government has once again seen the need for a national coastal vulnerability assessment, and a series of studies are planned or under way to achieve the aims of a National Climate Change Adaptation Framework.  相似文献   
95.
假如地球上没有人类据《新科学家》报道,毋庸置疑,人类是地球有史以来最具统治力的生物。仅仅数千年的时间,城市、农田和牧场就侵占了地球陆地超过1/3的面积。据估计,人类现在霸占了地球40%的生产力。人类的连番冲击让地球变得满目疮痍:草原变为耕地,森林夷为平地,地下蓄水层干枯;而核能废料、化学污染、入侵物种、生物灭绝及气候变暖都是人类活动造成的直接恶果。如果可能的话,与人类分享地球的其它生物会毫不犹豫地把我们“踢出”地球。现在,假设它们如愿以偿,地球上65亿人明天一夜之间从地球上消失,被送到遥远的星系接受再教育,那么,地球将会发生怎样的变化?  相似文献   
96.
A reconnaissance study was undertaken to determine potential contaminant exposures to children through soil from elementary school playgrounds. Soil samples were collected from areas along the Texas-Mexico border, inland areas (soils from elementary school yards in cities/towns within the state of Texas), and three National Parks (one on the border, one in Tennessee, and one in Washington). The present study focused on organochlorine (OC) pesticides as the potential contaminants of concern because of their historical (and possibly current) use, and their importance as persistent organic pollutants (POPs). DDE and heptachlor were the most frequently detected OCs (69 and 63%, respectively), although heptachlor concentrations in soil never exceeded 5 ppb. Relatively higher concentrations of DDE were observed in agricultural areas along the border (50-60 ppb in soils from McAllen, Palmview, and San Benito) than in other soils. However, a school yard in Lubbock, TX had the highest OC concentration observed (70 ppb dieldrin). These results may be due to historical agriculture activity prior to the banning of OC pesticides such as DDT in the early 1970s, as well as the more recent use of DDT in Central and South America for malaria control.  相似文献   
97.
轻型柴油车排放特性与机动车比功率分布的实例研究   总被引:5,自引:8,他引:5  
引入机动车比功率概念研究了驾驶条件(DrivingCondition)对机动车排放的影响及二者间的关系.利用美国Sensors公司生产的SEMTECH-D车载排放测试仪在上海选取2辆轻型柴油客货两用车开展了实际道路排放测试.测试道路包括城市快速道、主干道和次干道,2辆轻型车测试的道路全长分别为31·8和39·7km.通过计算逐秒的比功率值,研究了实际行驶中机动车比功率(VSP)与机动车油耗、空燃比和污染物排放的关系.回归分析结果表明,比功率比加速度能够更好地反映与NOx排放之间的关系,不同道路上机动车的CO、TC、NOx排放速率和油耗的比功率区间(VSPbin)分布具有较好的一致性.实测研究中VSPbin分布于-20~20kW·t-1的范围内,其中超过50%的数据分布在-3~1kW·t-1之间.高排放集中在分布频率较低的高VSP区间.应用污染物排放与VSP分布的关系式和VSPbins的频率分布可以估算机动车污染物排放总量.排放速率计算式具有一定的不确定性,还有待将来进一步修正.  相似文献   
98.
The reference method to quantify mixing ratios of the criteria air pollutant nitrogen dioxide (NO2) is NO-O3 chemiluminescence (CL), in which mixing ratios of nitric oxide (NO) are measured by sampling ambient air directly, and mixing ratios of NOx (= sum of NO and NO2) are measured by converting NO2 to NO using, for example, heated molybdenum catalyst or, more selectively, photolytic conversion (P-CL). In this work, the nitrous acid (HONO) interference in the measurement of NO2 by P-CL was investigated. Results with two photolytic NO2 converters are presented. The first used radiation centered at 395 nm, a wavelength region commonly utilized in P-CL. The second used light at 415 nm, where the overlap with the HONO absorption spectrum and hence its photolysis rate are less. Mixing ratios of NO2, NOx and HONO entering and exiting the converters were quantified by Thermal Dissociation Cavity Ring-down Spectroscopy (TD-CRDS). Both converters exhibited high NO2 conversion efficiency (CFNO2; > 90%) and partial conversion of HONO. Plots of CF against flow rate were consistent with photolysis frequencies of 4.2 s-1 and 2.9 s-1 for NO2 and 0.25 s-1 and 0.10 s?1 for HONO at 395 nm and 415 nm, respectively. CFHONO was larger than predicted from the overlap of the emission and HONO absorption spectra. The results imply that measurements of NO2 by P-CL marginally but systematically overestimate true NO2 concentrations, and that this interference should be considered in environments with high HONO:NO2 ratios such as the marine boundary layer or in biomass burning plumes.  相似文献   
99.
Invasive alien species are one of the primary threats to native biodiversity on islands worldwide. Consequently, eradicating invasive species from islands has become a mainstream conservation practice. Deciding which islands have the highest priority for eradication is of strategic importance to allocate limited resources to achieve maximum conservation benefit. Previous island prioritizations focused either on a narrow set of native species or on a small geographic area. We devised a prioritization approach that incorporates all threatened native terrestrial vertebrates and all invasive terrestrial vertebrates occurring on 11 U.K. overseas territories, which comprise over 2000 islands ranging from the sub‐Antarctic to the tropics. Our approach includes eradication feasibility and distinguishes between the potential and realistic conservation value of an eradication, which reflects the benefit that would accrue following eradication of either all invasive species or only those species for which eradication techniques currently exist. We identified the top 25 priority islands for invasive species eradication that together would benefit extant populations of 155 native species including 45 globally threatened species. The 5 most valuable islands included the 2 World Heritage islands Gough (South Atlantic) and Henderson (South Pacific) that feature unique seabird colonies, and Anegada, Little Cayman, and Guana Island in the Caribbean that feature a unique reptile fauna. This prioritization can be rapidly repeated if new information or techniques become available, and the approach could be replicated elsewhere in the world. Priorización de Islas para la Erradicación de Vertebrados Invasores en los Territorios Exteriores del Reino Unido  相似文献   
100.
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