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281.
论文基于2007—2010年中国30个省份区域间投入产出表数据,结合线性规划建立了多区域投入产出优化模型,研究了环境约束下中国八大经济区的出口结构优化。结果表明:2007—2010年需要提高服务业和农业的出口比重,同时降低煤炭开采和洗选业、造纸印刷及文教体育用品制造业、金属冶炼及压延业和电力热力生产供应业的出口比重,通过以上结构调整达到最优出口结构,可以实现在不增加碳、工业二氧化硫和工业废水排放的基础上促使全国GDP分别提高6.84%和8.17%。东北区域、黄河中游区域、长江中游区域、大西南区域和大西北区域需要降低的出口部门较多,且多集中在高能耗高排放产业;东部沿海区域、南部沿海区域、北部沿海区域需要提高的出口部门较多,主要集中在制造业和服务业,2010年东部沿海区域、南部沿海区域和大西北区域的总体出口结构优化度比2007年有所提高。在八大经济区中,东部沿海区域和南部沿海区域由于区位优势,其出口结构整体优化度相对较高,而东北区域则最低。地理区位对于区域出口结构优化具有一定程度的影响。 相似文献
282.
An environmental assessment of the management of organic household waste (OHW) was performed from a life cycle perspective by means of the waste-life cycle assessment (LCA) model EASEWASTE. The focus was on home composting of OHW in Denmark and six different home composting units (with different input and different mixing frequencies) were modelled. In addition, incineration and landfilling was modelled as alternatives to home composting. The most important processes contributing to the environmental impact of home composting were identified as greenhouse gas (GHG) emissions (load) and the avoided emissions in relation to the substitution of fertiliser and peat when compost was used in hobby gardening (saving). The replacement of fertiliser and peat was also identified as one of the most sensible parameters, which could potentially have a significant environmental benefit. Many of the impact categories (especially human toxicity via water (HTw) and soil (HTs)) were affected by the heavy metal contents of the incoming OHW. The concentrations of heavy metals in the compost were below the threshold values for compost used on land and were thus not considered to constitute a problem. The GHG emissions were, on the other hand, dependent on the management of the composting units. The frequently mixed composting units had the highest GHG emissions. The environmental profiles of the home composting scenarios were in the order of −2 to 16 milli person equivalents (mPE) Mg−1 wet waste (ww) for the non-toxic categories and −0.9 to 28 mPE Mg−1 ww for the toxic categories. Home composting performed better than or as good as incineration and landfilling in several of the potential impact categories. One exception was the global warming (GW) category, in which incineration performed better due to the substitution of heat and electricity based on fossil fuels. 相似文献
283.
LEE HANNAH 《Conservation biology》2010,24(1):70-77
Abstract: Climate change has created the need for a new strategic framework for conservation. This framework needs to include new protected areas that account for species range shifts and management that addresses large-scale change across international borders. Actions within the framework must be effective in international waters and across political frontiers and have the ability to accommodate large income and ability-to-pay discrepancies between countries. A global protected-area system responds to these needs. A fully implemented global system of protected areas will help in the transition to a new conservation paradigm robust to climate change and will ensure the integrity of the climate services provided by carbon sequestration from the world's natural habitats. The internationally coordinated response to climate change afforded by such a system could have significant cost savings relative to a system of climate adaptation that unfolds solely at a country level. Implementation of a global system is needed very soon because the effects of climate change on species and ecosystems are already well underway . 相似文献
284.
近地面大气臭氧(O3)含量不断升高对生态环境的影响已引起人们的广泛关注,然而O3含量升高对土壤有机碳的矿化及转化影响却少有研究。土壤有机碳是全球碳循环的重要组成部分,土壤碳库的微小变化将引起大气CO2浓度的显著改变。文章以典型土壤腐殖质单体化合物儿茶酚为代表,利用14C示踪技术,研究了O3含量比当前背景升高约0.15μmol·mol-1时对土壤中腐殖质苯酚类前体化合物的矿化及转化的影响。结果表明,O3含量升高会对土壤中培育12d后儿茶酚的矿化及残留物分布具有显著的影响,而且这种影响程度和规律同土壤有关。O3含量升高促进了黄棕壤中儿茶酚的矿化,增加了儿茶酚残留物在黄棕壤腐殖酸(HA)中的总量,并使残留物在HA中偏向于同大分子结合。O3含量升高对灰潮土中儿茶酚的矿化有抑制作用,但对儿茶酚残留在HA内总量及分布没有显著影响。O3含量升高对儿茶酚在土壤中的稳定性及归趋的影响可能是O3对于微生物活性的抑制作用和O3的直接氧化作用的共同结果。后续工作中应研究土壤腐殖质中其它组份的稳定性及转化对近地面大气O3含量升高的响应,以全面考察O3含量升高对土壤碳库的影响。 相似文献
285.
286.
土壤侵蚀环境演变与全球变化及防灾减灾的机制 总被引:1,自引:0,他引:1
以土壤侵蚀学和环境学的交叉为基础,讨论了土壤侵蚀环境学的内涵、土壤侵蚀环境演变及其调控、全球变化及防灾减灾的机制。为揭示土壤侵蚀的实质及制定土壤侵蚀的防治对策提供了新的思想。 相似文献
287.
George Halkos George Papageorgiou 《Journal of Environmental Planning and Management》2016,59(1):62-78
This paper computes and analyses, for the first time, environmental efficiencies in waste generation of 116 European regions in NUTS 2 level in five European countries over the period of 2008–2010. For this reason, different data envelopment analysis (DEA) model formulations are used for modeling the pollutant in the form of waste generation as a regular output and as a regular input. In the latter case, we also use the notion of eco-efficiency. The empirical findings reveal environmental inefficiencies among the regions, indicating the lack of a uniform regional environmental policy among the European countries. This finding is observed not only for regions between different countries but also among the regions within countries, implying the need for implementation of unified appropriate municipal environmental policies in waste management. 相似文献
288.
分析丘陵山区都市边缘的农村居民点土地利用空间特征,对于科学认识自然条件与社会经济发展交错影响下的新型农村人地关系具有重要意义。以重庆市两江新区为例,从居民点用地规模特征、居民点空间分异特征、居民点分形特征以及居民点空间格局四方面对农村居民点土地利用空间特征进行了分析。结果表明:两江新区农村居民点用地规模表现出明显的地域差异,在区域内部,受高程、坡度、地质灾害分布、水系、城镇和交通的影响,农村居民点用地表现出较强的空间分异特征,其中有相当一部分居民点的交通及基础设施条件亟待改善;两江新区内农村居民点分形维数介于1.12~1.53之间,由西南向东北方向逐步增大,围绕城市呈现"扇形圈层结构"特征,距离城镇越远农村居民点斑块结构越复杂;从居民点空间格局来看,两江新区镇域尺度上的农村居民点呈现出集聚、均匀与随机3种分布状态,图斑尺度的居民点受地形约束总体上呈条带状分布,在此基础上城镇发展的极化作用吸引农村居民点向城镇集中,形成若干聚集区。研究结果可为丘陵地区开展土地整治及模式探讨、土地利用规划筹提供参考。 相似文献
289.
Melinda R. Weathers Brenden E. Kendall 《Environmental Communication: A Journal of Nature and Culture》2016,10(5):593-611
News media are major channels for the transmission of information to the public and deliver news about the latest developments regarding health issues such as climate change. How the media frame such information may enhance public understanding and enable appropriate responses by individuals and communities. This study follows up on previous research examining media portrayals of climate change in US newspapers from 1 January 2007 to 31 December 2008. Here, we content analyze 270 news stories on climate change as a public health issue from five US newspapers between 1 January 2011 and 31 December 2012. Findings indicate that the total number of articles about climate change declined while emphasis on the public health dimension of climate change increased. The types of generic news frames (i.e., dramatic/substantive) most frequently used did not considerably change across the two time periods, however. To explain this, we discuss ways in which people may assess and spark change in news framing of public issues to better reach and influence a range of audiences. 相似文献
290.
Monika Djerf-Pierre John Cokley Louise J. Kuchel 《Environmental Communication: A Journal of Nature and Culture》2016,10(5):634-655
Australia and Sweden display very different institutional settings and contexts for the production of environmental journalism. This empirical study examined how two major quality newspapers in Sweden and Australia have framed renewable energy as an environmental, political, scientific, economic and civil society issue. A deductive, quantitative methodological approach was used to identify dominant frames and actors in articles in The Australian (Australia) and Dagens Nyheter (Sweden) between October 2010 and June 2011 2010/2011. The findings suggest that the attention given to different types of renewable energy in the two newspapers and how issues were framed was contingent on the domestication of the discussion of renewable energy in the two countries. Reporting on renewable energy in both newspapers was characterized by a focus on “elite” actors and economic frames, the absence of civil society frames and negative (The Australian) or ambiguous (Dagens Nyheter) environmental frames. The study extends our understanding of the contextual conditions that enable and limit journalists when reporting environmental issues. 相似文献