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41.
For the assessment of emission inventories matching pairs of activities (emission explaining variables) and emission factors are used. Simpler and detailed methodologies are proposed within the emission inventory handbooks. The data sets needed to serve the detailed methodologies have not been at public disposal so far. Therefore, this paper investigates the applicability of simpler methodologies to the statistical data sets of activities officially available in Germany. The statistical data base for the assessment of emissions from fertilised soils is adequate if one assumes that fertilisers sold in one financial year are applied in the same year. For grassland, statistical data describing the actual management do not exist. Lack of nitrogen inputs with crop residues and due to nitrogen fixation make it impossible to deduce the respective emissions. The assessment of indirect emissions due to reactions of leached nitrogen is also impossible. For extensively managed grasslands, data concerning fertiliser application or grazing are missing when calculating emissions. The determination of emissions from organic soils presupposes the knowledge of both the area concerned and the degree of mineralisation which has been attained at the time of the inventory. The results of the biennial animal census meet the requirements of the simpler methodologies. However, the assumptions made to evaluate the mean emission factors are not correct in many cases, as far as animal performance, housing, storage and application of animal excreta are concerned. The simpler methodologies are biassed, as the emission factors are (Northwest) European means. Changes in the raising of statistical data make the construction of meaningful time-series difficult.  相似文献   
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The assessment of the deposition of both wet (rain and cloud) and dry sedimenting particles is a prerequisite for estimating element fluxes in ecosystem research. Many nations and institutions operate deposition networks using different types of sampler. However, these samplers have rarely been characterized with respect to their sink properties. Major errors in assessing bulk deposition can result from poor sampling properties and defective sampling strategies. Relevant properties are: sampler geometry and material, in particular the shape of the rim; sink properties for gases and aerosols; and microbial transformations of the collected samples. An adequate number of replicates allows the identification of samples which are contaminated, in particular by bird droppings. The paper discusses physical and chemical properties of the samplers themselves. The dependence of measurement accuracy on the number of replicates and the sampling area exposed is discussed. Recommendations are given for sampling strategies, and for making corrections and substitution of missing data.  相似文献   
44.
An increasing percentage of agricultural land in Germany is used for oil seed plants. Hence, rape has become an important agricultural plant (in Saxony 1998: 12% of the farmland) in the recent years. During flowering of rape along with intensive radiation and high temperatures, a higher production and emission of biogenic VOC was observed. The emissions of terpenes were determined and more importantly, high concentrations of organic carbonyl compounds were observed during this field experiment. All measurements of interest have been carried out during two selected days with optimal weather conditions. It is found that the origin or the mechanism of formation of different group of compounds had strong influence on the day to day variation of their concentrations. The emission flux of terpenes from flowering rape plants was determined to be 16–32 μg h−1 m−2 (30–60 ng h−1 per g dry plant––540–1080 ng h−1 per plant), in total. Limonene, -thujene and sabinene were the most important compounds (about 60% of total terpenes). For limonene and sabinene reference emission rates (MS) and temperature coefficients were determined: βlimonene=0.108 K−1 and MS=14.57 μg h−1 m−2; βsabinene=0.095 K−1 and MS=5.39 μg h−1 m−2.

The detected carbonyl compound concentrations were unexpectedly high (maximum formaldehyde concentration was 18.1 ppbv and 3.4 ppbv for butyraldehyde) for an open field. Possible reasons for these concentrations are the combination of primary emission from the plants induced by high temperature and high ozone stress, the secondary formation from biogenically and advected anthropogenically emitted VOC at high radiation intensities and furthered by the low wind speeds at this time.  相似文献   

45.
An increasing percentage of agricultural land in Germany is used for oil seed plants. Hence, rape has become an important agricultural plant (in Saxony 1998: 12% of the farmland) in the recent years. During flowering of rape along with intensive radiation and high temperatures, a higher production and emission of biogenic VOC was observed. The emissions of terpenes were determined and more importantly, high concentrations of organic carbonyl compounds were observed during this field experiment. All measurements of interest have been carried out during two selected days with optimal weather conditions. It is found that the origin or the mechanism of formation of different group of compounds had strong influence on the day to day variation of their concentrations. The emission flux of terpenes from flowering rape plants was determined to be 16–32 μg h−1 m−2 (30–60 ng h−1 per g dry plant––540–1080 ng h−1 per plant), in total. Limonene, α-thujene and sabinene were the most important compounds (about 60% of total terpenes). For limonene and sabinene reference emission rates (MS) and temperature coefficients were determined: βlimonene=0.108 K−1 and MS=14.57 μg h−1 m−2; βsabinene=0.095 K−1 and MS=5.39 μg h−1 m−2.The detected carbonyl compound concentrations were unexpectedly high (maximum formaldehyde concentration was 18.1 ppbv and 3.4 ppbv for butyraldehyde) for an open field. Possible reasons for these concentrations are the combination of primary emission from the plants induced by high temperature and high ozone stress, the secondary formation from biogenically and advected anthropogenically emitted VOC at high radiation intensities and furthered by the low wind speeds at this time.  相似文献   
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Making index insurance attractive to farmers   总被引:1,自引:0,他引:1  
There are several factors that influence whether people will want to participate in index insurance programs. A number of these influence their attractiveness on economic grounds, including both the size and timing of the premium and potential payouts, and the degree of risk aversion of the potential customers. Other factors make programs attractive for reasons that are not economic, but no less valid. These have to do with the trust that people have in the insurance product and the organizations involved in selling and managing it. Indeed, data from India, Africa, and South America show that these factors may be more important than the economic ones in influencing demand. Index insurance pilot projects, in order to estimate demand for alternative products, have typically involved a great deal of interaction with potential customers. It is important to recognize that such interaction is crucial not just as a research tool, but also as a means to build understanding and trust in the products. When scaling up from isolated pilots to operational programs, it is vital to recognize this trust building function by replicating participation efforts in every community. In this paper, we examine the role of field games in establishing and building trust in three important aspects of these projects for participants: trust in the insurance product, trust in the participating organizations, and trust in their own ability to make good decisions. While games have previously been used as a way to gauge interest in the product and to identify design features, we argue that these games are also valuable tools for constructing these kinds of trust.  相似文献   
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This paper analyses how new information shapes public perception of a controversially discussed technology over time. The test case analysed in this paper is solar radiation management (SRM), a potentially risky, environmental engineering technology, which aims to fight climate change by the injection of sulphate aerosols into the stratosphere. Using panel survey data, we show that most respondents initially show strong negative emotions towards SRM and reject the technology. However, public perception is not stable over time as emotions cool off and acceptance increases. The increase in acceptance is greater, the longer the cooling-off period between two surveys. Furthermore, we show that the cooling-off effect is more pronounced for more impulsive respondents.  相似文献   
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