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221.
Christopher A. Airriess Wei Li Karen J. Leong Angela Chia-Chen Chen Verna M. Keith 《Geoforum》2008,39(3):1333-1346
This research examines the role of social capital and networks to explain the evacuation, relocation, and recovery experiences of a Vietnamese American community in New Orleans, Louisiana in the aftermath of Hurricane Katrina. As the single largest community institution, the parish church’s complex bonding and bridging social capital and networks proved particularly critical in part because of its historically based ontological security. The process of evacuation, but especially relocation and recovery, was dependent on deploying co-ethnic social capital and networks at a variety of geographical scales. Beyond the local or community scale, extra-local, regional, and national scales of social capital and networks reproduced a spatially redefined Vietnamese American community. Part of the recovery process included constructing discursive place-based collective-action frames to successfully contest a nearby landfill that in turn engendered social capital and networks crossing ethnic boundaries to include the extra-local African American community. Engaging social capital and networks beyond the local geographical scale cultivated a Vietnamese American community with an emergent post-Katrina cultural and political identity. 相似文献
222.
223.
G. N. Sadovnikov 《Stratigraphy and Geological Correlation》2008,16(1):31-46
A unique succession of volcanogenic deposits with representative paleontological remains characterizing the Permian-Triassic boundary interval in the North Siberian platform and Taimyr is described. The succession is suitable for selecting a standard for the Triassic base in nonmarine deposits. Abundant and diverse fossils occurring in the succession evidence that volcanism responsible for origin of the plateau basalt province in Siberia was not a brief epoch of paroxysmal eruptions, which eliminated everything alive. Throughout the formation history of relevant plateau basalts, the organic world of the plateau and around existed and gradually evolved. 相似文献
224.
Tidal inundation mapping under enhanced land subsidence in Semarang,Central Java Indonesia 总被引:3,自引:0,他引:3
Tidal inundation by high tide under enhanced land subsidence is a damaging phenomenon and a major threat to the Semarang urban
area in Indonesia. It impacts on economic activities, as well as the cost of an emergency program and causes interruption
of pubic services, danger of infectious diseases and injury to human lives. This study examines a spatial analysis tool on
the GIS-raster system for the tidal inundation mapping based on the subsidence-benchmark data and modified detail digital
elevation model. Neighborhood operation and iteration model as a spatial analysis tool have been applied in order to calculate
the encroachment of the tidal inundation on the coastal area. The resulting map shows that the tidal flood spreads to the
lowland area and causes the inundation of coastal settlement, infrastructure, as well as productive agricultural land, i.e.,
the fish-pond area. The monitoring of the vulnerable area due to the tidal inundation under the scenario of extended land
subsidence plays an important role in long-term coastal zone management in Semarang. 相似文献
225.
The state of land subsidence and prediction approaches due to groundwater withdrawal in China 总被引:13,自引:6,他引:7
This article gives a general introduction to land subsidence with the prediction approaches due to withdrawal of groundwater
in three subsided/subsiding regions in China: the deltaic plain of Yangtse River (YRDP), North China Plain (NCP), and Fenwei
Plain (FP). On YRDP, Shanghai is the typical subsided/subsiding city; on NCP Tianjin is the typical subsided/subsiding city,
and on FP Taiyuan is the typical subsided/subsiding city. The subsided area with subsidence over 200 mm on YRDP is about 10,000 km2 and the maximum subsided value reached 2.9 m at Shanghai; on NCP the subsided area reached 60,000 km2 with the maximum subsidence of 3.9 m at Tianjing; on FP the subsided area is relatively smaller than that on the other two
plains and is about 1,135 km2 with maximum subsidence of 3.7 m at Taiyuan city. In order to protect the civil and industrial facilities, it is necessary
to predict the future development of land subsidence based on present state. Many researchers proposed several approaches
to predict the land subsidence due to groundwater withdrawal according to different geological conditions and groundwater
withdrawal practice. This article classifies these approaches into five categories: (i) statistical methods; (ii) 1D numerical
method; (iii) quasi-3D seepage model; (iv) 3D seepage model; (v) fully coupled 3D model. In China, the former four categories
are presently employed in the prediction practice and their merits and demerits are discussed. According to the prediction
practice, 3D seepage model is the best method presently. 相似文献
226.
227.
南海西部海域构造复杂,主要发育有北东—北东东向、北西向和近南北向3组深大断裂。其中,北西向断裂与板块汇聚、碰撞有关,多具走滑性质;北东—北东东向断裂具有与中国东部裂谷盆地相似的发育特点,呈张扭性质;近南北向断裂可能是南海在扩张活动期间于洋、陆壳过渡部位形成的走滑调节断裂,是洋盆扩张的西部边界。新生代里,南海经历了4次成盆事件与3期扩张活动,盆地经历了古新世—中始新世陆缘断陷、渐新世—早中新世扩展与中中新世以来的热沉降3个演化阶段。陆缘断陷阶段的充填系列主要是北东—北东东向与北西向的河流—冲积扇、湖泊沼泽等陆相沉积及火山岩等;盆地扩展阶段表现为中-小型断陷、断-坳陷逐渐复合与联合为大-中型坳陷,古地理格局逐渐由河流与湖沼陆相环境演变为滨海至浅海相的沉积环境;热沉降阶段的成盆活动逐渐减弱以至停止,地层表现超覆,盆地出现联合迹象。结合以往勘探与油气资源调查成果分析,认为南海西部海域陆架陆坡区发育的大-中型沉积盆地石油地质条件良好,蕴藏着丰富的油气资源,勘探潜力巨大。 相似文献
228.
位于辽东湾西部低凸起北端的JZ20-2超压凝析气田,离供烃中心较远,压力系数却达到1.56~1.7,这在我国东部裂谷盆地比较少见。经过综合分析,作者认为JZ20-2凝析气田异常高压的形成与其所处的特殊地质背景紧密相关,辽中凹陷沙河街组三段超压凝析油气沿不整合面、砂体输导通道向辽东湾西部低凸起的运移、充注和能量的侧向传递是JZ20-2凝析气田异常高压形成的根本原因,而上覆东营组二段下亚段-东营组三段巨厚的强超压泥岩封盖和辽西3号边界断层侧向遮挡共同构成的优越封闭环境是超压保存的必要条件。本文分析了该气田超压特征及其远距离超压侧向传递的成因机制,不仅有助于揭示辽东湾西部低凸起超压流体运移聚集的规律和成藏作用,而且可能提供了一个超压远距离侧向传递的典型实例。 相似文献
229.
K. Vinod kumar R. C. Lakhera Tapas R. Martha R. S. Chatterjee A. Bhattacharya 《Environmental Geology》2008,55(4):789-799
Mass movements such as landslides in mountainous terrains are natural degradation processes and one of the most important
landscape-building factors. Varunawat Parbat overlooking Uttarkashi town witnessed a series of landslides on 23 September
2003 and the debris slides and rock falls continued for 2 weeks. This landslide complex was triggered due to the incessant
rainfall prior to the event, and its occurrence led to the blockage of the pilgrim route to Gangotri (source of the Ganges
river) and evacuation of thousands of people to safer places. Though there was no loss of lives due to timely evacuation,
heavy losses to the property were reported. High-resolution stereoscopic earth observation data were acquired after the incidence
to study the landslide in detail with emphasis on the cause of the landslide and mode of failure. Areas along the road and
below the Varunawat foothill region are mapped for landslide risk. It was found that the foothill region of the Varunawat
Parbat was highly disturbed by man-made activities and houses are dangerously located below steep slopes. The potential zones
for landslides along with the existing active and old landslides are mapped. These areas are critical and their treatment
with priority is required in order to minimise further landslide occurrences. 相似文献
230.
气候变化对塔里木河来自天山的地表径流影响 总被引:21,自引:10,他引:11
塔里木河水资源主要来自天山南坡两条源流,选择西段阿克苏河和中段开都河-孔雀河作为研究区.1956-2003年研究河源山区气温呈持续升温且降水波动增加的趋势,其中1995-2003年升温强劲,升温速率高出48 a期间平均的3倍以上;降水自1986年后持续增加,20世纪90年代较80年代增幅达18%,并显示出河源山区湿岛向塔里木盆地扩展.因高山缺少气象观测,出山径流过程变化可以综合反映中高山带的气候变化.塔里木河来自天山的地表径流在1986-2003年间持续增长,以冰川融水补给为主的库玛拉克河,1994年以来年径流量增加已在前期平均值基础上提升了一个台阶;开都河以降水径流补给为主,1986-2002年出现了观测记录以来的丰水期,并使1986年后博斯腾湖水位快速上升,恢复到1958年记录的最高水位以上.两河年径流变化趋势基本相似,但也显示有西、中段的气候变化局部差异,出现丰枯水期的不一致;然而,在近16 a升温过程中,年径流增长幅度和快慢相近. 相似文献