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1.
跨海桥隧工程设计需要推算工程位置不同重现期设计流速,由于现场缺乏长期实测流速资料,设计流速推算存在很大困难。研究提出了采用不同重现期典型风暴潮过程推算河口海岸设计流速的数值模拟方法,对河口地区考虑洪水径流与风暴潮流的耦合。在依据澳门验潮站1925—2003年实测潮位资料分析珠江口海域风暴潮过程特征的基础上,结合潮位和潮差年极值频率分析结果构建了不同重现期典型风暴潮潮型。采用平面二维水动力数学模型模拟了不同重现期风暴潮和上游一般洪水组合条件下珠江口水域的流场,得出港珠澳大桥沿线各控制点处设计流速。  相似文献   

2.
李勇  田立柱  裴艳东  王福  王宏 《地质通报》2016,35(10):1638-1645
基于ROMS海洋模式,结合近年的地质实测资料,建立了渤海湾西部地区风暴潮漫滩的数值模型。对模型进行验证后,对渤海湾西部区域重现期为50a、100a、200a及500a的风暴潮漫滩进行了数值模拟,分析了不同重现期风暴潮漫滩发展的动态过程及最大漫滩淹水范围。结果表明,数值模型基本能反映风暴潮的增水趋势,能够模拟风暴潮漫滩发生发展的动态过程。随着风暴潮强度的增加,渤海湾西部地区淹水范围具有从东海岸向西部内陆区域扩展的趋势。通过曲线拟合发现,风暴潮最大漫滩面积比值与高水位之间基本呈线性关系。  相似文献   

3.
沙埕港台风暴潮特征分析   总被引:1,自引:0,他引:1  
李克先  陈新加 《水文》2001,21(Z1):60-61
以沙埕港历史台风暴潮实测资料为依据,分析了影响增水的主要因素,并通过该港台风与增水特征的时应关系,初步揭示了产生这一现象的物理本质.  相似文献   

4.
王威  周俊  易长荣 《城市地质》2011,6(4):31-35
渤海湾沿海地区地面沉降严重、风暴潮灾害频发。本文以天津作为典型区域,对风暴潮潮位测定、风暴潮灾害和防风暴潮预案措施等方面开展研究,认为地面沉降对上述3方面均有的不同程度的影响,在风暴潮灾害防治中必须考虑地面沉降问题。  相似文献   

5.
给出了对渤海、南黄海和东海风暴潮的正压和层化浅海动力学特性的研究成果,简述了对海面风和风应力的诊断和预报结果、以及对浅海风暴潮的数值模拟实验和数值预报的效果,最后讲述了风暴潮理论在一些海洋工程上的应用。  相似文献   

6.
海岸地区致灾台风暴潮的长期分布模式   总被引:2,自引:0,他引:2       下载免费PDF全文
考虑台风导致的高水位和海浪波高对风暴潮灾害的贡献,对1949年以来影响青岛地区的台风暴潮进行了抽样统计.基于二维的泊松冈贝尔逻辑分布模式,对海岸地区的致灾风暴潮进行了长期的随机分析.与传统的警戒水位法不同,新模式能够反映多种环境荷载的综合作用,推算了青岛地区的特大台风暴潮灾害的重现期.计算结果显示,二维复合分布模式适合于描述台风暴潮过程中极值水位与相应波高的联合概率,所得结论对青岛地区的防潮减灾规划和工程建设具有指导意义.  相似文献   

7.
渤海湾西岸海岸带现代地质作用及影响因素分析   总被引:3,自引:0,他引:3  
李建芬  康慧  王宏  裴艳东 《华北地质》2007,30(4):295-301
通过对渤海湾西岸粉砂淤泥质海岸带的现代地质作用调查与分析,阐述了渤海湾海岸带在现代地质作用下侵蚀和淤积并存的现状:目前潮间带上部在不断淤高,而潮下带则存在侵蚀,正处于淤蚀过渡期。遥感资料及沉积物粒度的进一步分析,认为渤海湾西岸现代地质作用的影响因素及海岸带淤积泥砂主要来自岸滩下部及浅海区的侵蚀作用。提出在海岸开发中注意防淤的同时,高度重视侵蚀作用可能对海岸带造成的危害。  相似文献   

8.
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   

9.
渤海湾西岸贝壳堤堆积与海陆相互作用*   总被引:5,自引:3,他引:2  
渤海湾西岸淤泥质海岸已见两类砂体,滨外坝先形成于水下,而后随着海岸进积和在海洋动力作用下,逐渐出露于潮间带和陆地上; 另一种普遍出现的是具沿岸堤意义的贝壳堤,而且是在海岸进入弱侵蚀期即形成。研究发现,在海岸进积和海-陆相对稳定条件下,海岸线附近中潮坪-高潮坪受向岸风和波浪作用也可形成雏形贝壳堤砂体。目前研究区海岸上的贝壳堆积有3类,即:风暴潮堆积的沿岸堤型贝壳堤,主要堆积在中潮坪-高潮坪-滨海低平原上; 潮沟~潮汐河道型"贝壳堤",为潮汐河口湾顶或潮道外侧风暴贝壳堆积(自潮汐通道水下堆积延续到低地); 以及沿海低平原在大潮或风暴潮天气背景下出现的无序贝壳堆积。贝壳堤堆积既有风暴潮大浪瞬时、高能幕式堆积,又有大浪、向岸风综合作用下堆积的可能,贝壳测年及贝壳堤层序表明其形成是复杂的再堆积过程,不宜解释为海平面变化。在三角洲不均衡推进过程中,有可能形成不规则的海岸线,向岸风浪对不同地貌岸段的作用,可导致形成并非与现代海岸线平行的贝壳堤。贝壳堤术语的随意使用,已经造成海岸线变迁研究的简单化。严格使用沿岸堤的贝壳堤概念,可进一步划分三角洲叶瓣变迁,但是事件堆积必须剔除。将贝壳堤的研究与三角洲顶面泥炭测年相结合,可能更精确重塑海岸形成过程。  相似文献   

10.
刘宪斌  朱琳  李海明 《地学前缘》2005,12(2):178-178
天津海岸带位于华北平原的东北部,渤海湾西岸,是海陆相互作用十分强烈的地区,以堆积地貌为主,沉积物组成以粘土质粉砂、粉砂质粘土和极细砂等组成,在海岸类型划分上属于沉降平原粉砂淤泥质海岸(天津市海岸带和海涂资源综合调查报告,1987)。本文主要对上古林古贝壳堤、驴驹河古贝壳堤和宁河命俵口村进行了现场实地考察和研究,结合前人对古贝壳堤的研究成果(蔡爱智,1981;王宏等,2000;徐家声,1994;  相似文献   

11.
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.  相似文献   

12.
The Global Stratotype Section and Point (GSSP) for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy (SSS) proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy (ICS). The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob's Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs.  相似文献   

13.
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″.  相似文献   

14.
Important tendencies in development of the world mineral-resources sector at the beginning of the 21st century were an increase in production and consumption of mineral materials differentiated by types of metals and nonmetallic mineral raw materials, by countries and regions, as well as the concentration of the production of mineral raw materials in a small number of countries, and a reduction in industrial reserves of minerals in the world economy, even at the current stage of their extraction. These tendencies should be taken into account in working out a strategy for development of the Russian mineral raw-material base.  相似文献   

15.
Taking the example of W Sudan, an analysis of the climatic incidents leading to the two recent famine disasters is made. On this natural background, the human side is investigated. Focus is directed towards the fragile economic structure of the famine-prone population groups. An early-warning system for famine in the Sahelian Zone is proposed taking grain production and storage, livestock development and the relationship between the prices of livestock and grain as major indicators.  相似文献   

16.
东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。  相似文献   

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19.
郯庐断裂南段研究进展与断裂性质讨论   总被引:13,自引:3,他引:13  
据1:5万区域地质调查和专题研究资料,就郯庐断裂带是否南延与消失的原因,其与大别—苏鲁造山带交截形成的假位错效应,以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上,讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。  相似文献   

20.
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.  相似文献   

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