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1.
近年来我国海洋灾害损失及防灾减灾策略   总被引:2,自引:0,他引:2  
王爱军 《江苏地质》2005,29(2):98-101
我国是世界上海洋灾害最为严重的少数国家之一。近年来,由风暴潮、灾害性海浪、赤潮、海冰、海平面上升等海洋灾害带来的经济损失和人员伤亡越来越严重,其中,风暴潮是影响我国沿海地区最为严重的海洋灾害。通过建立海岸生态防护网、提高沿海地区防潮工程标准、开发海洋灾害监测和预报系统、实行海洋数据资料和信息共享等方法,降低海洋灾害发生的机率,减少海洋灾害损失。  相似文献   

2.
Phenomenal storm surge levels associated with cyclones are common in East Coast of India. The coastal regions of Andhra Pradesh are in rapid stride of myriad marine infrastructural developments. The safe elevations of coastal structures need a long-term assessment of storm surge conditions. Hence, past 50 years (1949–1998), tropical cyclones hit the Bay are obtained from Fleet Naval Meteorological & Oceanographic Center, USA, and analyzed to assess the storm surge experienced around Kakinada and along south Andhra Pradesh coast. In this paper, authors implemented Rankin Hydromet Vortex model and Bretschneider’s wind stress formulation to hindcast the surge levels. It is seen from the hindcast data that the November, 1977 cyclone has generated highest surge of the order of 1.98 m. Extreme value analysis is carried out using Weibull distribution for long-term prediction. The results reveal that the surge for 1 in 100-year return period is 2.0 m. Further the highest surge in 50 years generated by the severe cyclone (1977) is numerically simulated using hydrodynamic model of Mike-21. The simulation results show that the Krishnapatnam, Nizampatnam and south of Kakinada have experienced a surge of 1.0, 1.5 and 0.75 m, respectively.  相似文献   

3.
Storm surge, sea wave, sea ice, red tide and harmful marine creature bloom are main marine disasters occurring in the coast and offshore areas of Qingdao City, Shandong Province, China. Marine disasters mentioned above can be divided into five categories, namely, marine meteorological disasters, marine hydrological disasters, marine geological disasters, marine ecological disasters and man-made marine disasters. Over the past century, the marine disasters in the coast and offshore areas of Qingdao City have caused great economic losses and casualties. In recent years, some problems still exist in emergency management against marine disasters in Qingdao City, such as inaccurate predictions of disasters, untimely early warning and lack of social participation in the emergency management. On the basis of scenario analysis, the authors try to predict different possible scenarios of marine disasters at different early warning levels and propose some optimized emergency countermeasures against marine disaster in Qingdao City. Results of our research can provide a theoretical basis for the revision and improvement of emergency plans and thus guarantee timely and effective emergency management actions against marine disasters in Qingdao City.  相似文献   

4.
Zhang  Zhaohui  Zhang  Xuliang  Xu  Zongjun  Yao  Haiyan  Li  Ge  Liu  Xiujun 《Natural Hazards》2014,75(2):233-255

Storm surge, sea wave, sea ice, red tide and harmful marine creature bloom are main marine disasters occurring in the coast and offshore areas of Qingdao City, Shandong Province, China. Marine disasters mentioned above can be divided into five categories, namely, marine meteorological disasters, marine hydrological disasters, marine geological disasters, marine ecological disasters and man-made marine disasters. Over the past century, the marine disasters in the coast and offshore areas of Qingdao City have caused great economic losses and casualties. In recent years, some problems still exist in emergency management against marine disasters in Qingdao City, such as inaccurate predictions of disasters, untimely early warning and lack of social participation in the emergency management. On the basis of scenario analysis, the authors try to predict different possible scenarios of marine disasters at different early warning levels and propose some optimized emergency countermeasures against marine disaster in Qingdao City. Results of our research can provide a theoretical basis for the revision and improvement of emergency plans and thus guarantee timely and effective emergency management actions against marine disasters in Qingdao City.

  相似文献   

5.
An Analysis of the Recent Severe Storm Surge Disaster Events in China   总被引:3,自引:1,他引:2  
Kentang  Le 《Natural Hazards》2000,21(2-3):215-223
The economic loss caused by the storm surgedisasters is much higher than that caused by anyother marine disaster in China, the loss from the severestorm surge disaster being the highest. Statistics showthat there were 62 typhoon landings over the east-southeastcoast of China since 1990, three of which,occurring in 1992, 1994 and 1997, respectively, caused themost severe damage. The direct economic lossesdue to these events are 9.3, 17.0 and 30 billion yuan(RMB, or about 1.7, 2.6 and 3.8 billion USD,respectively), which is much greater than the loss of 5.5billion yuan (RMB) on an average every year duringthe 1989–1991 period. This paper makes a comparativeanalysis of the damage caused by the three events andpresents an overview of progress of precautions againststorm surge disaster in China. The suggestedcounter measures to mitigate the loss from the severe stormsurge disasters in China is as follows: (1) Raisethe whole society awareness of precaution against severestorm surge disaster; (2) Work out a new plan forbuilding sea walls; (3) Improve and perfect the availablewarning and disaster relief command system; (4)Develop the insurance service in order to promptly mitigatethe loss caused by severe storm surge disaster event.  相似文献   

6.
The glacier Sefstrombreen in Spitsbergen surged across an arm of the sea between 1882 and 1886 and rode up onto the island Coraholmen. Marine and terrestrial geological observations and archive records show that the glacier advanced on a deforming carpet of marine mud which was eroded from its original location, transported, and smeared over the sea bed and Coraholmen as a deformation till. The glacier emplaced about 2108M3 (0.2 km3) of drift in the terminal 2 km of its advance in a maximum of 14 years, leaving a thickness of up to 20 m on Coraholmen, which was doubled in size as a result.During the surge, subglacial muds were characterised by high water pressures, low effective pressures and low frictional resistance to glacier movement. Original sedimentary inhomogenities permit fold structures to be identified, but repeated refolding and progressive remoulding produce mixing and homogenisation of deformation tills.The surge was probably shortlived, and as the heavily crevassed glacier stagnated, underlying water saturated muds were intruded into crevasses and then extruded on the glacier surface. Reticulate “crevasse-intrusion” ridges on Coraholmen and the sea floor reflect the orientation of surge generated crevasses. Water and sediment was also extruded beyond the glacier at its maximum extent, to form extensive flows producing “till tongues” both on Coraholmen and the sea floor extending over 1.3 km from the glacier.It is argued that subglacial deformation of pre-existing sediment will almost invariably be associated with glaciation of marine areas and that this process will not only produce deformation tills through remoulding of pre-existing sediments, but will also play a fundamental role in glacier dynamics. Criteria which permit glacial tills produced by such events from marine and glaciomarine muds are discussed.  相似文献   

7.
黔中—渝南地区于紫云运动初期的泥盆纪末已准平原化,在石炭纪铝土矿含矿岩系沉积过程中,含矿岩系下段(铁质-粘土岩段)主要为近海湖泊相,含矿岩系上段(铝质岩段)为近海平原相。在这种大环境前提下,经常会受到海泛与强风暴潮的影响与改造,使得主要是陆相环境沉积形成的铝土矿含矿岩系中,含有少量海相大化石(腕足类)和微体生物化石(疑源类和牙形石);另在下段和上段岩矿层间,时夹海相碳酸盐岩透镜体,具明显海相沉积特征。以上表明,黔中—渝南石炭系铝土矿含矿岩系形成环境具有显著的多样性和复杂性,而非单纯的陆相沉积环境所能概括的。  相似文献   

8.
The length (more than 300 km) and size of the St. Narcisse morainic system suggest that it represents an important glacial event, probably climatically controlled and not related to a surge. Dates on marine material (shells) both from within and external to the moraine suggest that its time of emplacement was roughly 11,000 years ago, well after the beginning of the Champlain Sea Episode, but still possibly correlative with the Valders event of the Lake Michigan area.  相似文献   

9.
古风暴学是始于20世纪90年代的一门新兴学科,通过研究风暴活动的地质记录和历史文献资料,恢复器测之前几百年至数千年前的热带气旋活动规律。经过十几年的发展,逐渐形成一套包括研究领域、方法、技术与手段等比较完整的理论体系,成为第四纪古气候研究和过去全球变化的重要组成部分。古风暴学研究的替代指标包括:文字记载、特征的风暴事件沉积、海相化石组合、同位素地球化学组成等。这些指标单独使用时都有一定局限性。寻找新的替代指标,并运用多种指标综合分析方法提高古风暴事件的分辨率和可信度,是今后该学科发展的重要方向。已有的研究多侧重于古风暴频数的研究,今后应充分利用现代风暴潮理论的新进展,通过数值模拟与替代指标研究相结合,更准确地恢复古风暴强度。同时,应加强古风暴活动的全球对比研究,以揭示风暴活动与全球气候变化的关系,为在全球不断变暖背景下台风活动的情景预测提供依据。  相似文献   

10.
Submarine geomorphology is one of the main tools for understanding past fluctuations of tidewater glaciers. In this study we investigate the glacial history of Mohnbukta, on the east coast of Spitsbergen, Svalbard, by combining multibeam‐bathymetric data, marine sediment cores and remote sensing data. Presently, three tidewater glaciers, Heuglinbreen, Königsbergbreen and Hayesbreen calve into Mohnbukta. Hayesbreen surged at the end of the Little Ice Age, between 1901 and 1910. The submarine landform assemblage in Mohnbukta contains two large transverse ridges, interpreted as terminal moraines, with debrisflow lobes on their distal slopes and sets of well‐preserved geometric networks of ridges, interpreted as crevasse‐squeeze ridges inshore of the moraines. The arrangement of crevasse‐squeeze ridges suggests that both landform sets were produced during surge‐type advances. The terminus position of the 1901–1910 Hayesbreen surge correlates with the inner (R.2) terminal moraine ridge suggesting that the R.1 ridge formed prior to 1901. Marine sediment cores display 14C ages between 5700–7700 cal. a BP derived from benthic foraminifera, from a clast‐rich mud unit. This unit represents pre‐surge unconsolidated Holocene sediments pushed in front of the glacier terminus and mixed up during the 1901 surge. An absence of retreat moraines in the deeper part of the inner basin and the observation of tabular icebergs calving off the glacier front during retreat suggest that the front of Hayesbreen was close to flotation, at least in the deeper parts of the basin. As the MOH15‐01 core does not penetrate into a subglacial till and the foraminifera in the samples were well preserved, the R.1 ridge is suggested to have formed prior to the deposition of the foraminifera. Based on these data we propose that a surge‐type advance occurred in Mohnbukta in the early Holocene, prior to 7700 cal. a BP, which in turn indicates that glaciers can switch to and from surge mode.  相似文献   

11.
《Geodinamica Acta》2013,26(5-6):259-272
The contents and the distribution of clay minerals in modern sediments of the Cadiz bay and the continental shelf have been studied aiming to establish the sedimentary exchange model and the pathways followed by the clay fraction between the bay and the adjoining continental shelf. The most abundant clay minerals in the muddy sediments consist mainly of illite, smectite, interstratified illite-smectite, kaolinite and chlorite. The application of factor analysis method (PCA) to clay minerals data are considered to be useful in the determination of sedimentary transport patterns. The data from clay mineral assemblages, and their distribution map, make possible to establish the fine sediments transport paths in the study area using clay mineral as natural tracers. This model of transport takes in consideration the facies distribution, the supplies sources and the way of fine sediments are incorporated to the marine environment.

Two flows paths have been established: the outflows coming from Cadiz bay and the littoral zones; and the inflows coming from external marine zones of the bay. These flows are controlled by tidal currents and the morphology of the coast. The action of surge and the marine currents, specially the Atlantic Surface Water flow, are also important in the transport of fine sediments coming from sources located to the north of the study zone.  相似文献   

12.
Hurricane Gilbert made its landfall on the Yucatan peninsula on September 14, 1988, destroying valuable resort property in Cancun, Isla Mujeres, and Cozumel. Salt flats (salinas) in northern Quintana Roo and Yucatan were flooded by the storm surge and coastal marine ecosystem were devastated. Inland, the hurricane caused damages to houses, power lines, and farming land, but increased opportunities for garden hunting on destroyed fields. Twenty percent of tropical rain forest suffered losses of canopy and in the deciduous forests of north-central Yucatan noxiuous insects populations increased. Although damaging in its ultimate effects, hurricane Gilbert tested the resilience of Maya Indians and their readiness for post-disaster accommodation.  相似文献   

13.
风暴潮灾害风险评估研究综述   总被引:3,自引:0,他引:3  
我国是受风暴潮影响最严重的少数国家之一,风暴潮灾害致灾机理的研究在过去几十年取得了极大的进展,而风暴潮脆弱性评估和综合风险评估还不能满足风暴潮灾害风险管理的需求.系统总结了风暴潮危险性、脆弱性、综合风险评估及其应用的研究进展,重点分析了典型重现期风暴潮估计、可能最大风暴潮计算、风暴潮物理脆弱性和社会脆弱性评估以及风暴潮风险评估及其应用的研究进展及不足,并对我国风暴潮风险评估急需解决的问题以及未来的研究重点进行了展望,指出了风暴潮灾害风险评估的模型化、系统化、定量化是未来风暴潮风险评估研究的发展趋势,风暴潮灾害的未来风险评估还需考虑全球气候变化以及海平面上升等因素的影响,而风暴潮灾害承灾体脆弱性的定量评价是风暴潮综合风险评估的重点和难点.  相似文献   

14.
The storm surge in coastal Mississippi caused by Hurricane Katrina was unprecedented in the region. The height and geographic extent of the storm surge came as a surprise to many and exceeded pre-impact surge scenarios based on SLOSH models that were the basis for emergency preparedness and local land use decision-making. This paper explores the spatial accuracy of three interpolated storm surge surfaces derived from post-event reconnaissance data by comparing the interpolation results to a specific SLOSH run. The findings are used to suggest improvements in the calibration of existing pre-event storm surge models such as SLOSH. Finally, the paper provides some suggestions on an optimal surge forecast map that could enhance the communication of storm surge risks to the public.  相似文献   

15.
滑坡涌浪问题是近水滑坡灾害链上的一个重要的研究内容,长期以来一直是滑坡界、水电工程领域研究的难点和热点。特别是一些灾难性的滑坡涌浪事故的发生,使人们越来越认识到涌浪作为近水岸滑坡灾害链上的一个重要派生灾害。本文运用耦合的欧拉与拉格朗日(CEL)算法采用多种正交数值试验的方法研究了滑坡体形状、滑坡体前缘形态、滑坡体体积、滑面摩擦角及水面宽度等对滑坡涌浪的影响。通过研究发现:对于同体积的滑体而言,楔形体的滑体形成的涌浪最大,且楔形体的前缘角度越大形成的涌浪高度越高,这种影响在近场范围内影响更为显著; 滑坡体的体积对涌浪高度影响较大,随着体积的增加浪高呈现明显的增加趋势; 在相同条件下,滑面的摩擦系数越大所形成的涌浪高度越小; 由于受到阻挡作用,随着水面宽度的减小,涌浪高度呈现增高的趋势,尤其是涌浪爬坡高度有明显的增加。  相似文献   

16.
We here discuss the concept of the magnitude and the intensity of disaster of a storm surge and propose a method of calculation based on the principle of the wind scale and the earthquake magnitude. The magnitude of a storm surge is the quantitative index that describes the scale of the storm surge, and the intensity of disaster of a storm surge is the quantitative index that describes the losses caused by the storm surge.  相似文献   

17.
山东惠民凹陷古近系湖泊地震涌浪记录的新发现   总被引:4,自引:4,他引:4  
杨剑萍  王亚丽  查明  牟雪梅 《地质学报》2006,80(11):1715-1721
在陆相湖盆中,地震引起的各种作用力可以对各种先成沉积物进行改造而形成原地震积岩,同样地震可引发涌浪、浊流及碎屑流而形成地震涌浪沉积及震浊积岩.通过大量岩心观察描述和成像测井资料分析,首次提出惠民凹陷中央隆起带沙河街组含有丘状交错层理的碎屑岩与典型的原地震积岩(包括震裂岩、震褶岩、自碎屑角砾岩等)紧密共生,当属于地震作用引发涌浪的沉积产物.本区地震涌浪沉积中发育丘状及洼状层理、包卷层理、平行层理、块状层理、波痕、冲刷及截切面等沉积构造.根据沉积特征和分布位置,本区地震涌浪沉积划分为两种类型,即位于涌浪基面附近的含塑性泥砾的搅动型和涌浪基面与正常浪基面之间的回流型.垂向上地震涌浪沉积一般位于原地震积岩之上,震浊积岩之下,组成完整的原地震积岩—地震涌浪沉积—地震浊积岩序列或原地震积岩—地震涌浪沉积序列.本区地震涌浪沉积的发现和研究,将为地质学家识别陆相湖盆地震事件沉积提供对比标准.  相似文献   

18.
Geological identification of past tsunamis is important for risk assessment studies, especially in areas where the historical record is limited or absent. The main problem when using the geological evidence is to distinguish between tsunami and storm deposits. Both are high-energy events that may leave marine traces in coastal stratigraphic sequences. At Martinhal, SW Portugal both storm surge and tsunami deposits are present at the same site within a single stratigraphic sequence, which makes it suitable to study the differences between them, excluding variations caused by local factors.

The tsunami associated with the Lisbon earthquake of November 1st 1755 AD, had a major impact on the geomorphology and sedimentology of Martinhal. It breached the barrier and laid down an extensive sheet of sand, as described in eyewitness reports. Besides the tsunami deposit the stratigraphy of Martinhal also displays evidence for storm surges that have breached and overtopped the barrier, flooding the lowland and leaving sand layers. Both marine-derived flood deposits show similar grain size characteristics and distinctive marine foraminifera. The most important differences are the rip-up clasts and boulders exclusively found in the tsunami deposit and the landward extent of the tsunami deposit that everywhere exceeds that of the storm deposits. Identification of both depositional units was only possible using a collection of different data and extensive stratigraphical information from cores as well as trenches.  相似文献   


19.
《Sedimentary Geology》2006,183(1-2):145-156
Prehistoric depositional signatures for large-scale washover involving marine inundation events such as storms and tsunami have been the subject of considerable research over the last 15 years. Much of this research has focused on the identification of sandsheets in back-barrier environments as depositional records for extreme washover events. All these deposits must have a sediment source and, by their nature, the most likely source of sediment for washover into back-barrier environments is the barrier itself. This study identifies an erosional signature for large-scale washover from a small coastal barrier on the southeast Australian coast. A distinct lens of marine sand, up to 90 cm thick, confined vertically by peat, is found in the upper fill of a closed freshwater back-barrier lagoon sequence. This sand lens is attributed to a large-scale washover event during the last 800 years, and was possibly deposited by a tsunami. The hypothesis for this study was that any event that breached the dune system must have caused considerable geomorphic change to the dunes and hence may have left an erosional signature. Ground penetrating radar transects of the system show an erosional contact between a series of truncated pre-event dunes and several small overlying post-event dunes. This study outlines a relatively simple non-invasive method for the identification of an erosional signature for prehistoric large-scale washovers caused by storm surge, exceptionally large waves, or tsunami.  相似文献   

20.
地下工程涌突水是影响工程施工及运行的一个重要问题,目前对水电站地下工程涌突水危险性评价的研究较少。本文以自一里水电站为例,参考已有且较为完善的岩溶隧道涌突水及非可溶岩长深隧道涌突水的危险性评价方法,从地下水通道和地下水来源(补给)两个涌突水控制因素入手,综合分析各项要素,对自一里电站地下硐室的涌突水危险性进行初步分区。结果表明:自一里电站厂址区整体涌突水危险性较低,但在局部地段有发生涌水的可能。厂址区硐室按照涌突水危险性高低可分为较高危险区、中等危险区和低危险区。  相似文献   

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