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61.
常州市裸露地面风蚀扬尘排放清单及分布特征研究   总被引:3,自引:0,他引:3  
以2014年为基准年,以常州市行政边界为研究区域,利用卫星遥感解译的土地利用类型和裸土面积信息,并通过国土、气象等部门提供的土壤类型、气象因子等相关资料获取本地化因子和参数,估算常州市行政区域内裸露地面土壤扬尘中颗粒物的年排放量。结果表明:常州市裸露地面主要分布在金坛市、溧阳市和武进区,市中心区域最少,裸露土地利用类型主要为农田、滩涂、裸露山体、荒地及未硬化或未绿化的空地等;2014年常州市行政区域内裸露地面风蚀扬尘中TSP、PM 10、PM 2.5的年排放量分别为62.66 t、5.63 t、0.24 t,其中,金坛市土壤起尘量最大,其次为武进区,再次为新北区、溧阳市,市中心区域土壤扬尘最少。  相似文献   
62.
63.
Several wind tunnel experiments of tracer dispersion from reduced-scale landfill models are presented in this paper. Different experimental set-ups, hot-wire anemometry, particle image velocimetry and tracer concentration measurements were used for the characterisation of flow and dispersion phenomena nearby the models. The main aim of these experiments is to build an extensive experimental data set useful for model validation purposes. To demonstrate the potentiality of the experimental data set, a validation exercise on several mathematical models was performed by means of a statistical technique. The experiments highlighted an increase in pollutant ground level concentrations immediately downwind from the landfill because of induced turbulence and mean flow deflection. This phenomenon turns out to be predominant for the dispersion process. Tests with a different set-up showed an important dependence of the dispersion phenomena from the landfill height and highlighted how complex orographic conditions downwind of the landfill do not affect significantly the dispersion behaviour. Validation exercises were useful for model calibration, improving code reliability, as well as evaluating performances. The Van Ulden model proved to give the most encouraging results.  相似文献   
64.
The sensitivity of an integrated model to assess the potential for wind-borne spread of foot-and-mouth disease (FMD) to variations in key parameters controlling different physical and biological processes was evaluated. The estimated number of farms at risk is sensitive to the virus strain used and the accompanying effective contact rate. The C Noville strain increased the estimated number of exposed farms ranked as high and medium risk of being infected by a factor of 5, compared to the baseline, based on the O UKG 2001 strain. The inclusion of a model for biological ageing of the virus can also have a significant effect on the concentration patterns arising from transport and dispersion of the virus. Its inclusion has the practical advantage of markedly reducing the time required for the calculations. The estimated number of farms affected by exposure to high and medium virus concentrations is not grossly sensitive to attenuation caused by temperature or relative humidity effects. Changes in susceptibility to infection, as determined by the parameter θ in the exposure-risk model, does not change the configuration of the virus plumes, but it does change the distribution of farms at risk by risk category. These findings suggest that a good understanding of characteristics (excretion rates from infected animals, susceptibility of different species to infection, virus survival, etc.) of the virus strain involved in an FMD outbreak is necessary to provide a reliable assessment of the risk of wind-borne spread. In the event of an incursion of FMD, provision for laboratory studies on the virus will be an essential component of the disease response and should be factored into contingency plans.
X. YangEmail:
  相似文献   
65.
This work investigates the release and dispersion of volatile organic hydrocarbons, which may escape from external floating roof tanks (EFRT) during normal operation or in case of damage. The dispersion will be described using CFD simulations in close range of the EFRT where hazardous areas are assigned. The aim of this work is to investigate which events can lead to emissions in dangerous quantities and to estimate the corresponding likelihood with regard to explosion protection. An emission in hazardous amount is present if the lower explosion limit has been exceeded and if the extent of this emission is not too low. It is discussed in particular whether the used zoning of potentially explosive areas is conservative or over-conservative.  相似文献   
66.
Renewable energy often provokes heated debate on climate change, energy security and the local impacts of developments. However, how far such discussions involve thorough and inclusive debate on the energy and environmental-social justice issues associated with renewable energy siting remains ambiguous, particularly where government agendas prioritise renewable energy and planning systems offer limited opportunities for public debate on value-based arguments for and against renewable energy developments. Using the concept of justice self-recognition, we argue for greater attention to public discussion of the justice dimensions of renewable energy to assist in developing mechanisms to integrate distributive and procedural fairness principles into renewable energy decision-making. To explore how justice is currently invoked in such contexts, we examine recent U.K. policies for renewable energy and public submissions to applications for small-scale wind energy projects in Cornwall, U.K. The analysis of public comments revealed that justice concerns were rarely discussed explicitly. Comments instead did not raise concerns as justice issues or focused implicitly on distributive justice, stressing local aesthetic, community and economic impacts, clean energy and climate change. However, the findings indicated limited discussion of procedural or participatory justice, an absence that hampers the establishment of coherent procedures for deciding acceptable impacts, information standards, public participation and arbitrating disputes. We conclude by suggesting procedural reforms to policy and planning to enable greater public expression of justice concerns and debate on how to negotiate tensions between energy and environmental-social justice in renewable energy siting decisions.  相似文献   
67.
Data on the parameters of migration of two land snails of the genus Xeropicta are presented. In relatively homogeneous habitats, the locomotor activity of these mollusks is relatively high: they can travel for up to 300 cm per day, with neither the phenotype nor size of the shell having any significant influence on the level of dispersal. The snails prefer to travel westward and southward, but the distances covered by individuals moving in different directions are similar. No connection between the directions or distances of movement on two successive days has been observed.  相似文献   
68.
西藏阿里地区的林业资源及其发展方向探讨   总被引:1,自引:1,他引:1  
该文对西藏阿里地区林业资源的类型、数量、质量特征和生产现状进行了深入分析,同时,探讨了该地区林业生产存在的“资源结构简单、后续资源极端贫乏;资源分布不均,水平和垂直分异突出;宜林荒山荒地资源面积大,造林任务艰巨、生态环境破坏严重”等主要问题,提出了如下的对策和建议:①健全林业行政管理体制,加强林业资源管理;②节省薪柴,保护生态环境;③实行林地承包制,大力兴办林业;④加强林业科技投入,以科技兴林,走林业可持续发展之路。  相似文献   
69.
土壤退化研究的进展与趋向   总被引:39,自引:0,他引:39  
定义了土壤退化的概念 ,分析了全球及我国土壤退化概况 ,总结了土壤退化的研究进展 ,最后提出了土壤退化科学的研究方向  相似文献   
70.
环境保护执法新探   总被引:2,自引:0,他引:2  
环境执法的方式、手段起到优化作用.随着环境立法的完备和社会公众对环境质量要求的提高.如何加强环境执法的力度、改变环境执法的方式和执法领域.只有严格的执法才能保证和刺激政府、企业对环境服务的需求.通过建立完备的环境执法体系,坚决做到有法可依、有法必依、执法必严.以法规的形式,进一步明确环境保护行政主管部门的执法主体地位,调整和强化环保行政主管部门的管理职责,加大统一监管力度.做到法定执法权限,公开执法程序,明晰执法责任,规范执法行为.文章通过分析现行环境执法的缺陷,提出中国环境执法的优化目标和方向.  相似文献   
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