Temporal vulnerability in hazardscapes: Flood memory-networks and referentiality along the North Carolina Neuse River (USA)     

Daniel H. de Vries   《Global Environmental Change》2011,21(1):154-164

Social models of population vulnerability to disasters increasingly include the notion that vulnerability has a strong temporal component. While this temporality is typically conceptualized as objective (making vulnerability “dynamic,” “multiscalar,” and/or “historical”), it consistently fails to acknowledge that among stakeholders managing hazardscapes temporality is also a social process in which subjective experience of time may play a role in creating situations of population vulnerability. This paper proposes that the temporal situatedness of a population relative to past hazard events and the quality with which stakeholders engage hazard memory-chains combine to significantly influences its vulnerability to natural hazards. It is proposed that this temporal vulnerability is characterized by shared, population level potential for surprise and can be evaluated by exploration of time-series depth and temporal reference points in historical ecological narratives and documents. Based on ethnohistoric research conducted from 2002 to 2006 in flood-prone eastern North Carolina (USA), it is illustrated how temporal vulnerability was relatively higher in the Neuse River watershed located at the City of Kinston than surrounding watersheds. Due to the combination of factors including the damming of the Neuse River in the 1980s, outdated official floodplain maps, relatively unmonitored floodplain development, the stochastic timing of flood events (placing the last major flood more than a generation away), technological optimism, and turnover of floodplain officials and residents, local stakeholders were seriously misinformed about the space-time risks involved both before and after the disaster of Hurricane Floyd (1999) happened. To deal with this inconsistency, the temporal rarity of Hurricane Floyd as a “500-year event” has been motivated and embraced by many in an effort to continue life-as-is. The paper proposes that the concept of temporal vulnerability is further explored and used as key dimension in the vulnerability sciences.  相似文献   

Detecting tents to estimate the displaced populations for post-disaster relief using high resolution satellite imagery     

《International Journal of Applied Earth Observation and Geoinformation》2015

Estimating the number of refugees and internally displaced persons is important for planning and managing an efficient relief operation following disasters and conflicts. Accurate estimates of refugee numbers can be inferred from the number of tents. Extracting tents from high-resolution satellite imagery has recently been suggested. However, it is still a significant challenge to extract tents automatically and reliably from remote sensing imagery. This paper describes a novel automated method, which is based on mathematical morphology, to generate a camp map to estimate the refugee numbers by counting tents on the camp map. The method is especially useful in detecting objects with a clear shape, size, and significant spectral contrast with their surroundings. Results for two study sites with different satellite sensors and different spatial resolutions demonstrate that the method achieves good performance in detecting tents. The overall accuracy can be up to 81% in this study. Further improvements should be possible if over-identified isolated single pixel objects can be filtered. The performance of the method is impacted by spectral characteristics of satellite sensors and image scenes, such as the extent of area of interest and the spatial arrangement of tents. It is expected that the image scene would have a much higher influence on the performance of the method than the sensor characteristics.  相似文献   

三疣梭子蟹(Portunus trituberculatus)低盐耐受性和体重的遗传参数估计及其相关分析   总被引：1，自引：0，他引：1  

卢少坤  李荣华  母昌考  宋微微  郑维兵  王春琳 《海洋与湖沼》2015,46(5):1040-1045

为评估三疣梭子蟹(Portunus trituberculatus)体重及其低盐耐受性遗传力,本实验构建了20个三疣梭子蟹全同胞家系,分别在其60、90养殖日龄测量其各个家系的体重,并在60日龄时取每个家系90个个体,在盐度4胁迫下分别在12h、24h、48h、72h统计其死亡率,作为衡量其盐度耐受性指标。利用全同胞方差组分分析法评估其低盐耐受性及体重遗传参数。结果发现三疣梭子蟹在60日龄下,其体重遗传力为0.45,其在12h、24h、48h、72h处理条件低盐耐受性遗传力分别为0.13、0.18、0.21、0.29。通过聚类分析的方法将其耐受性状分为3类,并通过相关性分析发现三疣梭子蟹生长性状与低盐耐受性性状的相关系数为0.143,检验并不显著(P=0.547),说明三疣梭子蟹生长性状与耐低盐性状并不相关,在选育时可采用复合选育,提高育种效率。  相似文献   

Experimental research on horizontal bearing behavior of caisson-pile composite foundationEI北大核心CSCD     

Wang Lei  Guo Chao  Mu Bao-gang  Gong Wei-ming  Sun Zhen-wei 《岩土力学》2015,(11):3150-+

In this study, four groups of different types of bridge foundation model are tested to research the horizontal bearing behavior of caisson-pile composite foundation in lab based on the Qiongzhou Strait bridge project. The Q-s curve and horizontal ultimate bearing capacity of these four groups of foundations in sandy soil layer are obtained. Pile bending moment and shear force of pile shaft are analyzed in detail. At the same time, the load sharing ratio of caisson and piles is discussed. The results show that the horizontal ultimate bearing capacities of a single caisson foundation are increased by 1.2 times, 1.6 times and 2 times respectively with adding skirts, steel pipe pile, or steel pipe pile and the skirt. The maximum bending moment point is in the middle of the pile shaft, i.e. at about 0.5 m under the mud surface. The horizontal load is borne mainly by the upper caisson foundation and soil layers above the middle upper part of pile. The maximum shear force is found at the joint of pile top of steel pipe and caisson pile, where the reinforcement measures should be taken in practical engineering. The research achievements could provide a better reference for design or construction of caisson-pile composite foundation.  相似文献   

Geochemical characteristics and LA-ICP-MS zircon U-Pb age of the Lanhualing granite in Ningguo,Anhui ProvinceEI北大核心CSCD     

Chen F.  Wang D.  Du J.  Xu W.  Wang K.  Yu Y.  Tang J. 《大地构造与成矿学》2015,(2):369-377

The Lanhualing tungsten-molybdenum deposit is a skarn-type deposit located in Ningguo county, Anhui province. This deposit is mainly hosted in the Yinzhubu Formation and the Yanwashan Formation of Ordovician, and genetically related to the Lanhualing granite. The Lanhualing granite belongs to high-K calc-alkaline series with high alkali (Na2O+K2O=4.00%-7.03%), SiO2 (67.87%-74.92%) and MgO (0.62%-1.23%) contents. The granitic rocks show right-dipping chondrite normalized REE patterns with weak δEu anomalies. The granitic rocks are relatively enriched in large ion lithophile elements (LILE) and depleted in high field strength elements (HFSE). The ore-bearing granite was dated at 148.17±0.94 Ma by LA-ICP-MS zircon U-Pb method. The late Yanshanian is the main tungsten mineralization epoch in the South Anhui-north Jiangxi area; and indeed, the Dongyuan, Zhuxi, Yangchuling, Dahutang and other large and super-large tungsten deposits were formed in this period. Geochemical Characteristics of the Lanhualing granite indicate a crustal source but with mantle input under tectonic regime of compression thickening. ©, 2015, Science Press. All right reserved.  相似文献   

φ71 mm绳索取心铝合金钻杆的研制   总被引：1，自引：1，他引：0       下载免费PDF全文

张喜超 《探矿工程》2015,42(7):58-61，71

介绍了国内外铝合金钻杆的研制现状,分析了绳索取心铝合金钻杆在地质钻探中的优势。对φ71 mm×5.5 mm绳索取心铝合金钻杆体与钢接头连接结构进行了详细设计。通过对试验钻杆进行静拉力、扭矩试验,得出了铝合金钻杆体与钢接头主要技术参数。  相似文献   

青海祁漫塔格卡尔却卡铜多金属矿区矿床地质特征及控矿因素          下载免费PDF全文

高西平 《地质找矿论丛》2015,30(1):87-91

卡尔却卡地区是青海省重要的铁、铜、铅、锌、金多金属矿集区,具有特征明显的构造-岩浆岩带。在分析区内地层、构造、岩浆岩及接触带等控矿因素与成矿的关系的基础上,建立了找矿标志;根据区内的成矿特征,初步认为卡尔却卡多金属矿床为斑岩型矿床成矿系列,有斑岩型、夕卡岩型和蚀变岩型3种成因类型,形成斑岩-夕卡岩-热液成矿系统,成矿作用均与中-晚三叠世底侵事件有关。  相似文献   

皖南地区天井山金矿的矿化时空结构及矿体定位规律          下载免费PDF全文

陈昌明  曾令高  张均 《地质找矿论丛》2015,30(2):199-207

天井山金矿的矿化类型有石英脉型、蚀变岩型和千糜岩型,构成复合金矿化体系,各矿化类型的成因及时空配置具有密切的内在成生联系,组合产出特征明显。主成矿期成矿演化可以划分为微量金-石英阶段、金-单硫化物-石英阶段、金-多金属硫化物-石英阶段和微量金-萤石-方解石-石英阶段。矿体主要赋存于接触带构造及其附近,呈脉状、透镜状,膨大狭缩、尖灭再现、舒缓波状产出特征明显;断裂产状变化处及裂隙发育地段易于形成厚大富矿体,矿化发育程度与基性岩脉空间关系密切。矿体总体走向NE,具有浅部NW倾向、NE向侧伏,深部SE倾向、SW向侧伏的定位规律。其空间定位产出样式可分为外接触带型、接触带型和内接触带型。  相似文献   

鄂尔多斯盆地横山地区下石盒子组盒8段优势砂体研究     

宋平  高路恒  高小刚 《地下水》2015,(3)

横山地区位于盆鄂尔多斯盆地北部,上古生界下石盒子组盒8期处于辫状河三角洲平原与三角洲前缘过渡区。由于地形平缓、间歇性水流供给使得河流频繁改道。不同形态与规模的河道砂体交错叠置,加大连续沉积砂体的寻找难度。通过连井剖面追踪主河道内的单一砂体,揭示其空间展布规律,多条砂体追踪得到不同厚度砂体的空间延伸形态,其结果表明连续沉积越厚的砂体,其延伸距离越远。基于砂泥叠置关系与砂体发育规模确定优势砂体为多期次叠加的且隔夹层较少的具有一定规模的整套砂体。优势砂体空间延伸较远、沉积厚度较大、岩性较为均一,为理想的储集砂体。确定优势砂体的平面发育情况,为优势储层的寻找奠定基础。  相似文献   

竖向高荷载作用下大直径超长钻孔灌注桩承载性能试验     

桑伟锋 《世界地质》2020,39(1):127-134

通过机场—西华高速大直径超长钻孔灌注桩大吨位竖向单桩静载试验,分析了该地区大直径超长钻孔灌注桩的承载性状以及荷载传递机理。试验结果表明:试桩的Q-S曲线呈缓变型,桩端承载力占总荷载的比例均<10%,即均表现为摩擦桩特性;试桩的侧摩阻力自上而下逐步发挥,侧摩阻力和桩端阻力异步发挥且互相耦合;大直径超长钻孔灌注桩桩侧摩阻力的发挥与土层性质、土层埋深及桩顶荷载水平有关;在高荷载作用下桩侧上部土层摩阻力具有不同程度的软化现象,而中下部土层侧摩阻力具有不同程度的强化现象,甚至即使在最大加载情况下,桩身下部土层的侧摩阻力也并未完全发挥,因此在根据规范计算超长桩承载力时,不同深度土层的侧摩阻力应乘以相应不同的修正系数。  相似文献