首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
基于Copula函数的设计潮位过程要素组合风险分析   总被引:1,自引:1,他引:0       下载免费PDF全文
刘学  诸裕良  孙林云  孙波 《水文》2014,34(2):32-37
现行推求设计潮位过程大多采用高潮位与潮差同频率放大的方法,未考虑到二者遭遇可能性的大小。采用G-H Copula函数建立了年最高潮位和相应潮差的二维联合分布模型,通过组合风险分析法研究了设计高潮位和设计潮差的组合风险率。以天津港多年实测资料计算分析为例,结果表明:较大重现期的高潮位和潮差同时发生的概率较小,50年一遇高潮位与50年一遇潮差组合的风险率仅为0.05%,同频率设计偏安全,可依据组合风险率适当降低潮差设计标准。所采用的联合分布模型及其应用,在定量分析基础上为设计潮位过程的推求提供了一种新方法。  相似文献   

2.
毛兴华  顾圣华  唐桂兰 《水文》2013,33(2):11-14
利用代表潮位站吴淞站19752010年实测资料,分析了长江口潮位变化对潮型的影响。研究结果表明,随着年平均潮位的上升,代表站年平均高(低)潮位会相应抬升,二者线性相关关系非常密切,而潮差、潮历时与年平均潮位的相关关系不明显。另外,年最高(低)高(低)潮位、年最大涨(落)潮潮差、年最大(小)涨(落)潮历时等各项极值与年平均潮位变化也没有明显的相关关系。  相似文献   

3.
为研究南京站多年来年最高潮位的变化特征,根据水文变异综合诊断方法,分析检验了长江南京站近百年高潮潮位变化的整体趋势;利用db N系列小波变换分析了年高潮潮位变化的局部趋势;利用复数Morlet小波分析了年最高潮位的周期变化规律。分析结果表明,南京站年最高潮位序列总体上无明显趋势变化,局部变化趋势明显;年最高潮位存在5a、11a、42a和63a时间尺度四个主要变化周期。分析结果为认识南京站年最高潮位变化、做好水安全工作以及水资源的开发利用提供相关依据。  相似文献   

4.
根据大洋河流域规划设计,通过水文分析,计算大洋河河道各频率洪峰流量、分析洪水特性,由于邻近大洋河口的大鹿岛站为临时站,潮水位资料匮乏,因而把大东港站潮位资料作为本次潮水位设计的理论依据,同时计算不同频率潮位,将大鹿岛站作为大洋河河口的设计潮位,计算结果可知:发生20年和100年一遇洪水时,对应起点水位分别为4.22 m和4.51 m。计算结果可供相关规划设计部门参考。  相似文献   

5.
周月英  关帅 《水文》2018,38(5):1-5
针对同倍比方法与同频率方法推求设计潮位过程线中的局限性,采用4种边际分布函数对珠江口年最高潮位与年最大潮差序列进行拟合的基础上,选取4种不同的二维Archimedean Copula函数建立珠江口年最高潮位与年最大潮差的联合分布,并分析了高潮位重现期与潮位过程同现重现期的线性关系。结果表明:高潮位与潮差的同现重现期总是大于相应边际分布的重现期,并且随着边际分布重现期的增大,同现重现期增幅也越大,说明较高重现期的高潮位与潮差同时发生的可能性很小;基于高潮位重现期与潮位过程同现重现期的线性关系,采用基于联合分布的方法推求珠江口潮位过程线,推求结果较同频率法更为合理。  相似文献   

6.
基于潮流数值模拟的设计潮位推算方法   总被引:2,自引:0,他引:2       下载免费PDF全文
针对一些拟建工程位于潮位不易观测地区的情况,提出了一种设计潮位的推算方法。首先,通过潮流数值计算,获得拟建工程地点一个月以上的短期潮位过程;其次,与临近的、具有长期实测资料的港口或验潮站的潮位进行同步相关分析,建立回归方程;最后,采用《海港水文规范》中的方法推算港口或验潮站的设计潮位,并将其由回归方程换算至拟建工程地点。通过算例的计算分析,表明本文方法是合理的、可行的。  相似文献   

7.
谢欣荣 《水文》2011,31(2):27-31
广义极值分布频率曲线,也可采用均值、变差系数和偏态系数等三个统计参数来进行计算。通过建立离均系数表,可以方便地进行频率分析计算。现以澧水某站年最大流量系列为例,采用广义极值分布的适线法进行频率分析计算,成果表明广义极值分布具有一定适应性。  相似文献   

8.
可考虑历史洪水信息的广义极值分布线性矩法的研究   总被引:3,自引:1,他引:2  
陈元芳  李兴凯  陈民  许睢  马斌勋 《水文》2008,28(3):8-13
在水文及其他行业中广义极值分布(GEV)是一种较为常用的分布线型,包括极值Ⅰ型、极值Ⅱ型和极值Ⅲ型分布.在介绍了该分布线性矩与其参数关系后,给出了有效的可以考虑历史洪水信息的线性矩公式,并对由线性矩推求分布密度函数中k值作了改进.通过统计试验计算分析了线性矩在该分布中的统计性能及历史洪水公式的适用性,并与绝对值准则和平方和准则两种不同优化适线法、矩法作了比较.统计试验表明,改进k值计算后的线性矩法略优于传统线性矩法.从总体上讲,改进k值计算后的线性矩法优于平方和准则适线法及矩法,其参数及设计值的不偏性很好,与绝对值准则适线法总体上相当.  相似文献   

9.
福建沿海设计潮位查算图研制   总被引:4,自引:1,他引:3  
李松仕  林永泉  胡美英 《水文》2000,20(1):26-30
就目前在推求设计位中若干争议的问题进行了分析,应用统计假设检验理论研究了年最高潮位的随机性,提出了通过区分不同的组合概率法推求设计潮位的新方法,根据福建沿海位资料研制了设计潮位查算图,以便于无潮位观测资料的地区查求出设计潮位。  相似文献   

10.
刘宏宽 《水文》2022,42(3):27-31
为研究极端高潮位对上海吴淞口设计高潮位(千年一遇)的影响,采用无偏估计计算初值、P-Ⅲ型曲线目估适线,研究了吴淞口1985—2018年逐年设计高潮位变化。结果表明9711和0012台风期间产生的极端高潮位分别提升设计高潮位0.184 m和0.128 m。对未来情景,采用MCMC和MetropolisHastings抽样生成1000组与历史序列趋势一致的样本序列,研究了未来30年出现0次、1次、2次极端高潮位对2050年吴淞口设计高潮位的影响,结果较现状(2018)6.58 m分别约提升2 cm、14 cm和24cm。平均每遇到一次极端高潮位,吴淞口设计高潮位上升约10~12 cm。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

14.
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.  相似文献   

15.
PALEONTOLOGY     
正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)  相似文献   

16.
正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)  相似文献   

17.
正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)  相似文献   

18.
PETROLOGY     
正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,  相似文献   

19.
正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an  相似文献   

20.
正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号