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381.
Climate change caused by carbon emissions continuously threatens sustainable development. Due to China’s immense territory, there are remarkable regional differences in carbon emissions. The construction industry, which has strong internal industrial differences, further leads to carbon emission disparity in China. Policymakers should consider spatial effects and attempt to eliminate carbon emission inequality to promote the sustainable development of the construction industry and realize emission reduction targets. Based on the classic Markov chain and spatial Markov chain, this paper investigates the club convergence and spatial distribution dynamics of China’s carbon intensity in the construction industry from 2005 to 2014. The results show that the provincial carbon intensity in the construction industry is characterized by “convergence clubs” during the research period, and very low-level and very high-level convergence clubs have strong stability. Moreover, the carbon intensity class transitions of provinces tend to be consistent with that of their neighbors. Furthermore, the transition of carbon intensity types is highly influenced by their regional backgrounds. The provinces with high carbon emissions have a negative influence on their neighbors, whereas the provinces with low carbon emissions have a positive influence. These analyses provide a spatial interpretation to the “club convergence” of carbon intensity.  相似文献   
382.
The factors that explain the speed of recovery after disaster remain contested. While many have argued that physical infrastructure, social capital, and disaster damage influence the arc of recovery, empirical studies that test these various factors within a unified modeling framework are few. We conducted a mail survey to collect data on household recovery in four small towns in southern Indiana that were hit by deadly tornadoes in March 2012. The recovery effort is ongoing; while many of the homes, businesses, and community facilities were rebuilt in 2013, some are still under construction. We investigate how households in these communities are recovering from damage that they experienced and the role of social capital, personal networks, and assistance from emergency responders on the overall recovery experience. We used an ordered probit modeling framework to test the combined as well as relative effects of (a) damage to physical infrastructures (houses, vehicles, etc.); (b) recovery assistance from emergency responders (FEMA) as well as friends and neighbors; (c) personal network characteristics (size, network density, proximity, length of relationship); (d) social capital (civic engagement, contact with neighbors, trust); and (e) household characteristics. Results show that while households with higher levels of damage experienced slower recovery, those with recovery assistance from neighbors, stronger personal networks, and higher levels of social capital experienced faster recovery. The insights gained in this study will enable emergency managers and disaster response personnel to implement targeted strategies in facilitating post-disaster recovery and community resilience.  相似文献   
383.
红色精灵是一种发生于闪电放电活跃的雷暴云上空的中高层大气瞬态发光现象,它们通常由中尺度对流系统层状云降水区内的强地闪回击产生,是对流层和中间层之间的一种能量耦合过程。目前,有关中国南海及东南亚地区的红色精灵观测鲜有报道。为了进一步了解热带地区产生红色精灵事件的沿海性雷暴特征,于2019年利用低光度光学观测系统和低频磁场天线在马来西亚马六甲地区开展了地基观测。实验于11月9日、12月11日和12月15日三次在沿海雷暴上空共捕捉到7例红色精灵事件,其中包括4例圆柱型、2例胡萝卜型和1例舞蹈型。结合闪电定位、云顶亮温和低频磁场信号等同步数据,分析表明所有事件均由正极性地闪回击产生,且母体闪电回击位于雷暴对流区附近(云顶亮温≤ 210 K处),这可能是该地区产生红色精灵的沿海性雷暴的共同特征。此外,红色精灵生成期并不是闪电活动最强期,而是发生于闪电频数短暂降低后,这表明红色精灵的发生可能是该地区成熟雷暴中对流减弱的一个信号。  相似文献   
384.

Background

In June 2018, the European Parliament and Council of the European Union adopted a legislative regulation for incorporating greenhouse gas emissions and removals from Land Use, Land Use Change and Forestry (EU-LULUCF) under its 2030 Climate and Energy Framework. The LULUCF regulation aim to incentivise EU Member States to decrease greenhouse gas emissions and increase removals in the LULUCF sector. The regulation, however, does not set a target for increasing the LULUCF carbon sink, but rather includes a ‘no net debit’ target for LULUCF (Forests and Agricultural soils). For Managed Forest Land (MFL) an accounting framework with capped credits for additional mitigation against a set forest reference level (FRL) was agreed for 2021–2030. The FRL gives the projected future carbon sink in the two compliance periods 2021–2025 and 2026–2030 under “continuation of forest management practices as they were in the reference period 2000–2009”. This FRL was disputed by some Member States as it was perceived to put a limit on their future wood harvesting from MFL. Here we simulated with the EFISCEN European forest model the “continuation of forest management practices” and determined the corresponding wood harvest for 26 EU countries under progressing age classes.

Results

The simulations showed that under “continuation of forest management practices” the harvest (wood removals) in the 26 EU countries as a whole can increase from 420 million m3/year in 2000–2009 to 560 million m3/year in 2050 due to progressing age classes. This implies there is a possibility to increase absolute wood harvests without creating debits compared to the forest reference level. However, the manner in which ‘continuation of forest management’ developed with a progressing age class development over time, meant that in some countries the future harvesting exceeded 90% of the increment. Since this generally is considered to be unsustainable we additionally set a harvesting cut-off as max 90% of increment to be harvested for each individual country as a possible interpretation of sustainability criteria that are included in the regulation. Using this additional limit the projected harvest will only increase to 493 million m3/year.

Conclusions

The worry from Member States (MS) that the FRL will prevent any additional harvesting seems unwarranted. Due to differences between Member States concerning the state of their forest resources, the FRL as a baseline for harvesting works out very differently for the different Member States. The FRL may have other unforeseen consequences which we discuss. Under all scenarios the living forest biomass sink shows a decline. This can be counteracted through incentivising measures under Climate Smart Forestry.
  相似文献   
385.
南北钦防城市群作为西部地区经济发展的重要增长极,在我国沿海经济发展格局中占有重要地位.为了正确认知南北钦防城市群土地利用变化的时空演化特征,本文采用1990、2000和2013年3期土地利用分类数据,通过分类统计、GIS空间分析方法,土地利用转移矩阵与土地利用动态度分析了1990—2013年土地利用数量变化、转移方向以及土地利用动态度区域差异特征.  相似文献   
386.
387.
林宝玉  李明  黄莫  邓丽婷 《地质论评》2021,67(3):67040025-67040025
《中国扬子区兰多维列统特列奇阶及其与英国的对比》一书(陈旭,戎嘉余,1996)有以下结论:①将回星哨组、茅山组、西坑组等的层位归属于特列奇阶上部;②将回星哨组、茅山组及其相当地层与英国特列奇阶对比;③将扬子区特列奇阶的顶界置于回星哨组、茅山组及其相当地层之顶;④将回星哨组、茅山组、西坑组等地层资料编制的古地理图称为特列奇期晚期古地理图;⑤将回星哨组、茅山组、西坑组等地层与上覆中泥盆统—中二叠统之间的不整合面代表的上升运动,称为“特列奇期的扬子上升”。笔者等依据多年对扬子地台志留纪地层剖面的实地考察和近数十年来扬子区坟头组中—上部、茅山组、回星哨组、小溪峪组、西坑组等地层中文洛克世、拉德洛世、普里多利世早期古生物化石的发现,认为:①回星哨组、小溪峪组、茅山组、西坑组等的层位是文洛克统—普里多利统;② 回星哨组、小溪峪组等大致与英国的文洛克统—普里多利统对比;③回星哨组、小溪峪组、茅山组的顶界是文洛克统—普里多利统剥蚀后残留的层位随地而异的顶界;④根据回星哨组、西坑组、茅山组等地层资料编制的古地理图应是文洛克世—普里多利世古地理图;⑤“扬子地台整个上升”(黄汲清,1945)的时代是志留纪末期,没有“特列奇期的扬子上升”。特提出商榷。上述这些地层时代的解决,对扬子区志留系4统层序的建立具有重要意义,而且也为中国扬子区与英国命名剖面志留系的对比以及中国南方早古生代加里东运动最后一幕时代的再次确定提供了地层学和古生物方面的依据。  相似文献   
388.
Kim  Ji Eun  Yu  Jisoo  Ryu  Jae-Hee  Lee  Joo-Heon  Kim  Tae-Woong 《Natural Hazards》2021,109(1):707-724

Due to the complex characteristics of drought, drought risk needs to be quantified by combining drought vulnerability and drought hazard. Recently, the major focus in drought vulnerability has been on how to calculate the weights of indicators to comprehensively quantify drought risk. In this study, principal component analysis (PCA), a Gaussian mixture model (GMM), and the equal-weighting method (EWM) were applied to objectively determine the weights for drought vulnerability assessment in Chungcheong Province, located in the west-central part of South Korea. The PCA provided larger weights for agricultural and industrial factors, whereas the GMM computed larger weights for agricultural factors than did the EWM. The drought risk was assessed by combining the drought vulnerability index (DVI) and the drought hazard index (DHI). Based on the DVI, the most vulnerable region was CCN9 in the northwestern part of the province, whereas the most drought-prone region based on the DHI was CCN12 in the southwest. Considering both DVI and DHI, the regions with the highest risk were CCN12 and CCN10 in the southern part of the province. Using the proposed PCA and GMM, we validated drought vulnerability using objective weighting methods and assessed comprehensive drought risk considering both meteorological hazard and socioeconomic vulnerability.

  相似文献   
389.
海底块状硫化物(SMS)蕴藏有丰富的Cu、Cd、Au、Fe、Ag、Co等战略性金属,是未来可供人类开发利用的战略资源.本文搜集了全球3 946组SMS化学成分数据,根据构造环境可将其分成4类(快速、中速、慢速、超慢速扩张)洋中脊型和2类(弧后扩张中心和弧火山)岛弧型SMS矿床.利用多元统计方法分析了SMS战略性金属的分布特征和主控因素,探讨了其资源前景.结果表明:洋中脊型SMS矿床富集Cu+Fe+Co±Mo,而岛弧型普遍富集Zn+Pb+Cd+Sb+Ag±Au等关键元素.分析表明,成矿温度、成矿物质来源、酸碱度和氧化还原条件是战略性金属富集的主要影响因素,其中流体温度主要受水深条件控制,成矿物质来源主要受控于构造地质环境,酸碱度和氧化还原性主要受控于围岩类型.Cu+Au+Fe+Co在水深超过约2 650 m的慢速—超慢速扩张脊非转换不连续带和拆离断层带等区域具较好的勘查前景;而Cu+Au+Cd+Ag在水深约1 080~2 160 m的弧后扩张中心区域具较好的勘查前景.   相似文献   
390.
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