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31.
通过核实从数据采集到标准时点阶段发生变化的内容,补充新增内容,消除普查前阶段由于资料时效性和外业局限性等导致的现势性不统一现象,对变化的地理国情信息进行核准,使地理国情普查数据成果在时间上达到统一,是开展地理国情监测的基础。  相似文献   
32.
A detailed study of long-term variability of winds using 30 years of data from the European Centre for Medium-range Weather Forecasts global reanalysis (ERA-Interim) over the Indian Ocean has been carried out by partitioning the Indian Ocean into six zones based on local wind extrema. The trend of mean annual wind speed averaged over each zone shows a significant increase in the equatorial region, the Southern Ocean, and the southern part of the trade winds. This indicates that the Southern Ocean winds and the southeast trade winds are becoming stronger. However, the trend for the Bay of Bengal is negative, which might be caused by a weakening of the monsoon winds and northeast trade winds. Maximum interannual variability occurs in the Arabian Sea due to monsoon activity; a minimum is observed in the subtropical region because of the divergence of winds. Wind speed variations in all zones are weakly correlated with the Dipole Mode Index (DMI). However, the equatorial Indian Ocean, the southern part of the trade winds, and subtropical zones show a relatively strong positive correlation with the Southern Oscillation Index (SOI), indicating that the SOI has a zonal influence on wind speed in the Indian Ocean. Monsoon winds have a decreasing trend in the northern Indian Ocean, indicating monsoon weakening, and an increasing trend in the equatorial region because of enhancement of the westerlies. The negative trend observed during the non-monsoon period could be a result of weakening of the northeast trade winds over the past few decades. The mean flux of kinetic energy of wind (FKEW) reaches a minimum of about 100?W?m?2 in the equatorial region and a maximum of about 1500?W?m?2 in the Southern Ocean. The seasonal variability of FKEW is large, about 1600?W?m?2, along the coast of Somalia in the northern Indian Ocean. The maximum monthly variability of the FKEW field averaged over each zone occurs during boreal summer. During the onset and withdrawal of monsoon, FKEW is as low as 50?W?m?2. The Southern Ocean has a large variation of about 1280?W?m?2 because of strong westerlies throughout the year.  相似文献   
33.
Energy-intensive industries play an important role in low-carbon development, being particularly exposed to climate policies. Concern over possible carbon leakage in this sector poses a major challenge for designing effective carbon pricing instruments (CPI). Different methodologies for assessing carbon leakage exposure are currently used by different jurisdictions, each of them based on different approaches and indicators. This paper aims to analyse the extent to which the use of different methodologies leads to different results in terms of exposure to the risk of carbon leakage, using the Brazilian industry sector as a case study. Results indicate that carbon leakage exposure is an expected outcome of eventual CPI implementation in Brazilian industry. However, results vary according to the chosen methodology, so the definition of the criteria is paramount for assessing sectoral exposure to the risk of carbon leakage.

Key policy insights

  • Despite increasing discussion about the implementation of carbon pricing on the Brazilian industrial sector, the evaluation of carbon leakage risks is still neglected.

  • Assessments of the risk of carbon leakage are directly related to the indicators and criteria used by each methodology. Thus, a given subsector may present different levels of exposure to carbon leakage depending on the methodological choice.

  • More than a purely technical discussion, the methodological definition of carbon leakage risk is a political discussion – it can be well-conducted, leading to the success of a CPI, or even sabotaged, by implicitly subsidizing energy-intensive industries.

  相似文献   
34.
地面强风可直接造成人员伤亡和经济损失,严重影响出行安全、工农业生产等社会秩序。强风的发生与天气系统和复杂下垫面的共同作用密切相关,在城市区域尤为明显。受数值模拟技术和计算资源的限制,对实际天气条件下大范围城区的强风现象进行建筑物分辨率的大规模数值模拟研究仍是一个挑战。本研究利用中尺度气象模式嵌套流体计算动力模式的超高分辨率局地气象预报系统,对强冷空气过程造成广州市区的一次强风事件进行数值模拟,深入探讨强风的精细结构和形成机制。结果表明,伴随着强冷空气入侵,广州市区的平均风速和风场高频扰动均明显增强,且在城市冠层顶尤为明显,呈现区域不均匀的三维结构,数值模拟与地面观测相一致。较大范围的强风速和阵风主要出现在建筑物较为低矮的老城区上空,并持续影响下游河道等开阔区域。在高层建筑密集的新城区,虽然整体风速明显减弱,但能在平行风向的街道狭管和下游区域形成局地强风。特别是,超高层建筑群引起显著的垂直环流,导致强风扰动向下传播,造成最大风速达8 m s?1的地面局地强风,阵风指数接近2。上游建筑群引起的风场扰动呈现大尺度湍流结构,能沿着平均气流传播影响数公里之远的下游地区。当风场扰动经过广州塔等单体超高层建筑时,可在其两侧绕流区再次加强,形成局地强风。局地强风和阵风还出现在垂直于风向排列的沿江高层建筑群的侧边,与建筑屏风的阻挡效应和缺口溢出有关。研究结果促进认识城市强风的时空特征和物理机制,有助于提升城市气象的精细化预报水平。  相似文献   
35.
There is an increased demand for the accurate prediction of fog events in the Sichuan Basin (SCB) using numerical methods. A dense fog event that occurred over the SCB on 22 December 2016 was investigated. The results show that this dense fog event was influenced by the southwest of a low pressure with a weak horizontal pressure gradient and high relative humidity. This fog event showed typical diurnal variations. The fog began to form at 1800 UTC on 21 December 2016 (0200 local standard time on 22 December 2016) and dissipated at 0600 UTC on 22 December 2016 (1400 local standard time on 22 December 2016). The Weather Research and Forecasting model was able to partially reproduce the main features of this fog event and the diurnal variation in the local mountain to basin winds. The simulated horizontal visibility and liquid water content were used to characterize the fog. The mountain to basin winds had an important role in the diurnal variation of the fog event. The positive feedback mechanism between the fog and mountain to basin winds was good for the formation and maintain of the fog during the night. During the day, the mountain to basin wind displayed a transition from downslope flows to upslope flows. Water vapor evaporated easily from the warm, strong upslope winds, which resulted in the dissipation of fog during the day. The topography surrounding the SCB favored the lifting and condensation of air parcels in the lower troposphere as a result of the low height of the lifting condensation level.  相似文献   
36.
河南省活立木交易市场发展现状及前景分析   总被引:1,自引:0,他引:1  
建立河南省活立木交易市场不仅能够促进全省林业发展,实现林木资源的规范流转,提高林农的经济收益,而且还可以提高森林覆被率、改善生态环境,并对林木资源的可持续发展起着重要作用.以河南省活立木交易市场为例,系统地阐述了活立木交易的有关概念、活立木交易市场发展中取得的成绩和存在的问题;针对市场发展中存在的问题提出了一些可行性的建议;最后对河南省活立木交易市场的发展前景进行了分析.  相似文献   
37.
The live reef food fish (LRFF) trade has an estimated annual retail value of US$1 billion in the Asia-Pacific region and at least US$30 million in the Philippines. Palawan Province is the trade's center accounting for as much as 55% of the commodity's total export. Concern about the LRFF trade has caused the Palawan Provincial government to take action to regulate the trade. Four key policy options to address the short-term policy objective of developing a sustainable LRFF industry through the reduction of threats associated with destructive fishing and overfishing were proposed. These four policy options and associated analyses were presented to stakeholders at three separate policy consultations. The stakeholders reached a consensus that a regulated LRFF trade was the most sensible option. As a result, the Provincial Government of Palawan took action to enact “The Palawan Live Reef Fish Ordinance of 2006”, which provides for the sustainable and integrated regulation of the LRFF industry. This provincial ordinance will assist in crafting a national policy for the LRFF trade and may also be useful in revising the 1998 Philippine Fisheries Code. The key challenge is how to translate the ordinance provisions into effective on-the-ground actions.  相似文献   
38.
本文简要介绍了现代测绘性质、作用、地位及本学科的发展方向;较为详细叙述了现代测绘的主要技术的发展状况及 3S集成的广阔应用前景;简述了数字地球的概念及其主要支撑技术、与现代测绘关系,及现代测绘的主要任务;在迎接21世纪的挑战中,提出一些建议,供研究参考。  相似文献   
39.
全球手机贸易网络演化特征研究   总被引:3,自引:2,他引:1  
基于复杂网络方法,运用Pajek、Ucinet、Gephi等软件,构建全球手机产业贸易网络,探究2001-2016年全球手机产业贸易网络结构及其演化过程。根据研究发现全球手机贸易网络呈现稠密化发展趋势,网络整体遵循“核心-边缘”的圈层结构,结构内部不断演化和重组;全球手机贸易网络呈现由双核主导向多核演变,空间格局上形成由欧美日发达国家向东亚发展中国家的转移趋势;全球手机贸易网络的四大子群网络板块特征明显,且随着时间的发展而发生变化。  相似文献   
40.
黎诗扬  朱华晟  丁玥 《地理科学进展》2019,38(10):1514-1522
随着中国人口红利逐渐消失,劳动力技能升级的问题日益突出。已有研究表明,发展中国家融入全球生产网络体系并非必定能够促进劳动力技能的升级。论文以中国大陆地区主要地级市为例,利用2005、2010、2015年的面板数据,试图分析国际贸易对各地区劳动力技能结构变动及技能升级方面的影响。结果表明:出口贸易对地区高技能劳动力就业比重具有抑制作用,表现为出口贸易对劳动力技能降级的影响;而进口贸易所产生的技术扩散效应尚未显现,进出口贸易整体影响并不显著。进一步来看,从区域产业地理格局角度,对外贸易影响了不同技能水平劳动力人群的区域间流动,使得对外贸易对劳动力技能升级的影响效果在不同的区位与城市规模特征间存在显著差异。沿海城市和大城市主要表现为进口贸易显著促进高技能劳动力就业比重进而带来地区劳动力技能升级,相对于内陆地区和小城市而言,出口贸易会带来高技能劳动力就业比重下降,地区劳动力技能呈现降级趋势。  相似文献   
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