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121.
Past changes and possible future variations in the nature of extreme precipitation and flood events in Central Europe and the Alpine region are examined from a physical standpoint. An overview is given of the following key contributory physical processes: (1) the variability of the large-scale atmospheric flow and the associated changes of the North-Atlantic storm track; (2) the feedback process between climate warming and the water cycle, and in particular the potential for more frequent heavy precipitation events; and (3) the catchment-scale hydrological processes associated with variations in major river flooding events and that are related to land-use changes, river training measures, and shifts in the proportion of rain to snowfall. In this context an account is provided of the possible future forecasting and warning methodologies based upon high-resolution weather prediction and runoff models. Also consideration is given to the detectability of past (future) changes in observed (modeled) extreme events. It is shown that their rarity and natural fluctuation largely impedes a detection of systematic variations. These effects restrict trend analysis of such events to return periods of below a few months. An illustration using daily precipitation from the Swiss Alps does yield evidence for pronounced trends of intense precipitation events (return period 30 days), while trends of stronger event classes are not detectable (but nevertheless can not be excluded). The small detection probability for extreme events limits possible mitigation of future damage costs through an abatement of climate change alone, and points to the desirability of developing improved early forecasting/warning systems as an additional no-regret strategy. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
122.
This communication summarizes the main findings of INASUD, an European-wide research project on integrated assessment of climate policies. The project aimed at improving the framing of climate policy analysis through the parallel use of various existing integrated assessment models. It provides a comprehensive examination of the link between uncertainty regarding damages and inertia in economic systems. Results show that the Kyoto targets and timing are consistent with the precautionary principle but offers little insurance for longer-term climate protection. Flexibility mechanisms offer potentials for cooperation with developing countries, and are necessary to tap the environmental and economic benefits of joint carbon and sulfur emissions abatement.  相似文献   
123.
It is indicated that up to the year 2030, the annual average temperatures in China will increase by 0.88 to 1.2°C, with increments in the south less than in the north. Annual average precipitation would raise slightly, but the increment could be 4% in northeastern China. The increment of annual mean runoff could rise over 6% in the northeastern area, and decrease in the other regions 1.4 to 10.5%. The increased water shortage due to climate change could achieve 160 to 5090 million m3 in some areas of China. Financial loss due to the lack of water could reach 1300 million yuan, and up to 4400 million yuan in serious drought years in the Beijing-Tianjin-Tangshan area.  相似文献   
124.
利用唐山市1976-2005年各县年降水序列,分析了该市降水的空间分布规律和时间变化特点。采用灰色系统的灾变预测方法,对各县分别建立了GM(1,1)模型,进行未来25年唐山市各站的干旱年预测。利用残差检验、后验差检验和关联度检验对各模型分别进行了精度检验。结果表明,预测模型精度较高,可以对唐山市各县未来的干旱年进行预测,从而为科学决策提供依据。  相似文献   
125.

Problem

Psychometrically validated measurement tools are needed to evaluate an organization's safety climate. In 2000, Gershon and colleagues published a new healthcare safety climate measurement tool to determine its relationship to safe work behavior (Gershon, R., Karkashian, C., Grosch, J., Murphy, L., Escamilla-Cejudo, A., Flanagan, P., et al. (2000). Hospital safety climate and its relationship with safe work practices and workplace exposure incidents. American Journal of Infection Control, 28, 211-21). The present study evaluated the psychometric properties of the Gershon tool when modified to address respiratory rather than bloodborne pathogen exposures.

Method

Medical practitioners, nurses, and nurse aides (n = 460) were surveyed using the modified Gershon tool. Data were analyzed by factor analysis and psychometric properties of the tool evaluated.

Results

Eight safety climate dimensions were extracted from 25 items (Cronbach's alpha range: 0.62 - 0.88). Factor extractions and psychometric properties were reasonably consistent with those of the Gershon tool.

Impact on Industry

The Gershon safety climate tool appears to have sufficient reliability and validity for use by healthcare decision makers as an indicator of employee perceptions of safety in their institution.  相似文献   
126.
127.
基于TM与MODIS遥感数据的农业旱情监测——以河北省为例   总被引:4,自引:0,他引:4  
以河北省冬小麦种植区域为研究区,基于TM和MOD IS遥感数据,利用植被供水指数法确定了研究区旱情等级。首先,将其与遥感解译获得的冬小麦空间分布图叠加得到受灾冬小麦空间分布图;然后以1 km的距离在受灾冬小麦周围做缓冲区,并与通过人口密度模型获得的人口密度空间分布图叠加,得出受灾人口空间分布;最后基于光能利用率改进模型构建粮食产量回归统计模型,得到粮食产量。目的是从粮食产量和作物受灾影响人口两个方面对农业受干旱影响情况进行遥感监测和定量评价,以期为相关部门制定防灾、抗灾措施提供科学依据。结果表明,2004年研究区:(1)春季受灾面积小,仅占16.4%;(2)旱情较轻,以轻旱为主,占受灾面积的89%;(3)冬小麦种植面积约为23 965.0 km2,受灾面积约606.3 km2,主要位于唐山市和保定市;(4)粮食产量回归统计模型精度达到了87%,冬小麦产量约为11939247 t,单产约为498.8 t/km2。  相似文献   
128.
中国北方地区干旱化趋势与防御对策研究   总被引:22,自引:3,他引:19  
利用最新的气象资料,计算并分析了中国北方地区与干旱有关的气象因素(可能蒸散量、水面蒸发量和降水量)的区域分布及其20世纪90年代的变化情况,结果表明,从总体上来看,20世纪90年代的干旱程度略轻于前30年的平均水平,但地区间存在显著差异,内蒙古东部地区,京津冀地区干旱有所缓解,山西大部分地区、陕西、宁夏南部、甘南及青海部分地区,则干旱有所发展,其它大部分地区的干旱程度几乎没有变化,最后,根据该地区的具体情况,提出了相应的防御干旱进一步发展的对策。  相似文献   
129.
分析陕西省2000年天气气候变化发现,隆冬降雪明显增多,春旱异常严重,秋霖明显,沙尘暴天气明显增加,这是多年来未曾见到的现象。异常的天气气候使得多种自然灾害并发。  相似文献   
130.
How do choices among information sources reinforce political differences on topics such as climate change? Environmental sociologists have observed large-scale and long-term impacts from news media and think-tank reports, while experimental science-communication studies detect more immediate effects from variations in supplied information. Applying generalized structural equation modeling to recent survey data, previous work is extended to show that political ideology, education and their interaction predict news media information choices in much the same way they predict opinions about climate change itself. Consequently, media information sources serve as intervening variables that can reinforce and, through their own independent effects, amplify existing beliefs about climate change. Results provide empirical support for selective exposure and biased assimilation as mechanisms widening political divisions on climate change in the United States. The findings fit with the reinforcing spirals framework suggesting partisan media strengthens climate change beliefs which then influences subsequent use of media.  相似文献   
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