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1.
陈子燊  位帅 《海洋通报》2020,39(5):530-535
使用美国北卡罗来纳州的 FRF 1985—2016 年的极值波高及其持续时间数据,采用最优的 Gumbel-Hougaard copula函数和 Kendall 分布函数构建极值波高和相应历时不同组合的联合概率分布模式,分析各个组合的遭遇概率、“或”重现期、“且”重现期和 Kendall 重现期,以出现最大可能概率的方法推算各组合联合设计值。结果表明:Kendall 重现期所对应的累积频率更准确地代表了特定设计频率下的风险率;重现期分别为 5 年、10 年、20 年、50 年、100 年、200 年推算的 Kendall重现期设计值介于“或”重现期和“且”重现期设计值之间,小于相应的边缘分布设计值;基于 Kendall 重现期的极值波高及其持续时间不同重现期组合推算的结果可为海洋工程构筑物设计与风险管理提供新的选择与参考。  相似文献   

2.
球形棕囊藻(Phaeocystisglobosa)是我国南方沿海近年来主要的赤潮原因种之一,由球形棕囊藻形成的赤潮对海水养殖业发展和海域生态环境构成了严重威胁。棕囊藻通常以囊状群体形式形成赤潮,很难获取其丰度数据,以往研究中多以19′-己酰氧基岩藻黄素(Hex-fuco)或19′-丁酰氧基岩藻黄素(But-fuco)作为其特征色素,利用化学分类软件CHEMTAX计算其生物量。为了解我国近海球形棕囊藻的色素组成特征,本文采用高效液相色谱方法,分析了6株球形棕囊藻的色素组成与含量状况,其中5株分离自我国近海。结果表明, 6株球形棕囊藻均以岩藻黄素和叶绿素a为主要色素,但其特征色素Hex-fuco却存在显著的株系间差异,即便是分离自相同海域的不同球形棕囊藻藻株也存在差别。对比棕囊藻游离细胞和囊状群体的色素组成,可以看出两者在色素组成上基本一致,但囊状群体中捕光色素(Light-harvesting pigment)含量低于游离细胞,而光保护色素(Photoprotective pigment)则高于游离细胞,可能与不同存在形态的棕囊藻对光照的适应特征差异有关。以上研究表明,在以CHEMTAX方法计算球形棕囊藻生物量时,需要充分调查海域棕囊藻的特征色素组成情况,获取其特征色素信息,构建合理色素比例初始矩阵,为球形棕囊藻赤潮监测奠定基础。  相似文献   

3.
Ninteen species of subfamilies Imbricariinae and Cylindromitrinae, family Mitridae, are recorded from the China's seas. Of which, one genus and six species are recorded for the first time from China's seas, i.e., genus Ziba Adams H and Adams A, Cancilla (Cancilla) carnicolor, Ziba duplilirata, Z. insculpta, Neocancilla circula, Scabricola (Scabricola) desetangsii, Scabricola (Swainsonia) ocellata ocellata.  相似文献   

4.
Soft computing tools in the form of combination of multiple nonlinear regression and M5'' model tree were used for estimation of overtopping rate at the vertical coastal structures. For reliable and precise estimation of overtopping rate, the experimental data available in the database CLASH were used. The dimensionless overtopping rate was estimated in terms of conventional dimensionless parameters including the relative crest freeboard Rc/Hs, seabed slope tanθ, deep water wave steepness Som, surf similarity ξom and local relative water depth ht/Hs. The accuracy of the new model was compared with other existing models and also evaluated with some field measurements. The results indicated that the model presented in this paper is more accurate than other existing models. With statistical parameters, it is shown that the accuracy of predictions in the new model is better than that of other models.  相似文献   

5.
船舶压舱水可引起外来生物入侵,国际海事组织(International Maritime Organization, IMO)因此制定了具有约束力的压舱水公约,已于2019年1月对我国正式生效。大量研究证明船舶压舱泥是有害藻华种类特别是有害甲藻孢囊的携带者。另一方面,有害藻华在我国近三十年频发,尤其是新的种类不断出现。因此,这种态势是否与压舱泥带来的外来种入侵有关是一个具有重要科学和现实意义的问题。我们最近的工作表明,此前国内外通过形态学方法对压舱泥的检测都大大地低估了甲藻孢囊的种类多样性和样品间种类组成的异质性。因此,必须通过更深入全面的实证研究对外源有害藻华甲藻通过压舱泥入侵我国海域进行风险评估。本文从如下几个方面进行了综述与讨论:(1) 船舶压舱水(泥)与有害藻华地理扩散;(2) 国内外有关压舱泥中甲藻孢囊多样性的检测与溯源研究;(3) 我们对美国港口船舶压舱泥的检测发现压舱泥中甲藻孢囊具有很高的种类多样性和样品间的异质性。最后从我们最近的工作及与文献报道的工作比较获得了几个重要的科学问题。在评述国内外研究成果和前期研究结果基础上,提出有必要通过更大量、广泛的国际船舶压舱泥和中国全海域沉积物取样、高通量测序的分子鉴定与形态观察、单孢囊分子-形态鉴定、孢囊萌发、全面生信分析相结合的技术路线,实证性地评估有害藻华种类通过压舱泥入侵中国的风险,并以此建立对新出现藻华种类溯源或判断是否外来种入侵的基本依据,同时为海关职能部门的检验执法提供依据。  相似文献   

6.
基于3种生物指数的三沙湾养殖活动底栖环境效应研究   总被引:2,自引:1,他引:1  
彭广海  付婧  马增岭  周进 《海洋学报》2018,40(4):106-118
为考察我国东海区最为典型养殖海湾三沙湾养殖活动的底栖环境效应,本研究根据2016年8月航次41个样品采集站位的数据,分析香农-威纳多样性指数(Shannon-Wiener index,H')、海洋生物指数AMBI(AZTI's Marine Biotic Index)和多变量海洋生物指数M-AMBI(Multivariate-AMBI)在4种典型水域(网箱、海藻、鲍鱼养殖和无养殖水域)间的差异及其与沉积物环境因子(δ15N、δ13C、C/N比、总有机碳、总氮、总磷、硫化物、含水率和粉粒-黏粒比例)的相关性。结果表明,航次共采集74种大型底栖生物,H'介于0~3.51;物种多属环境敏感类型(AMBI方法中EGⅠ和EGⅡ生态组),AMBI指数介于0~4.13,M-AMBI指数介于0.30~0.77。3种生物指数的分布水平表明此海域总体底栖生态质量良好,仅在局部水域存在显著扰动。Kruskal-Wallis检验显示仅H'在不同类型水域之间存在显著差异(P<0.05),后续配对检验(Pairwise comparision)显示大黄鱼养殖水域H'显著高于海藻养殖水域(P<0.01)。基于斯皮尔曼秩相关系数(Spearman correlation coefficient)的相关性分析表明仅H'和M-AMBI指数分别与总磷存在显著相关性(P<0.05)。聚类分析(Cluster analysis)结果显示不同类型站位在聚类图中随机分布,聚类结果未体现出采样水域的差异性。综上,基于3种生物指数的分析结果显示三沙湾内网箱等典型养殖活动未对区域底栖生境质量造成显著影响。  相似文献   

7.
基于多项式回归模型的岛礁遥感浅海水深反演   总被引:4,自引:4,他引:0  
Lyzenga's模型由于简单有效得到广泛应用,但是模型易欠拟合导致精度不高。本文提出了一种基于Lyzenga's模型的改进模型,通过增加多项式次数的方法,扩大模型特征维度,使得反演模型正确拟合,从而提高反演精度。基于WorldView-2遥感影像和0~30 m实测水深数据反演岛礁周围浅水水深,使用10折交叉验证和模型残差分析两种方法验证了改进模型的有效性和鲁棒性。结果表明,改进模型精度更高,在多项式次数为3时,模型最优。最后,根据改进模型反演得到的水深建立岛礁水下地形模型,能够直观、丰富地表达岛礁礁盘的微地形信息。  相似文献   

8.
南沙海区万安盆地构造演化与成因机制   总被引:2,自引:1,他引:1  
本文基于地震、钻井和区域地质资料,运用回剥法和平衡剖面技术定量研究了万安盆地的构造沉降和伸展程度,重建盆地的构造演化史并探讨其成因机制。模拟结果表明,万安盆地构造沉降曲线为多段式,其南北部构造沉降差异明显,且沉降中心逐渐向南发展的趋势。晚始新世-渐新世(37.8~23.03 Ma BP)盆地中、北部快速沉降,存在两个沉降中心;早中新世(23.03~16.0 Ma BP)盆地南部也发生快速沉降,整个盆地存在3个沉降中心;中中新世(约16.0~11.63 Ma BP)沉降作用减弱,盆地进入裂后热沉降期。万安盆地的伸展和形成演化呈现北早南晚的特征,与南海海底扩张密切相关,同时受控于万安断裂带交替地右旋-左旋走滑作用,是伸展和走滑双重作用的结果。盆地的构造演化过程可细分为4个阶段:初始裂谷期、主要裂谷期、走滑改造期和裂后加速沉降期。  相似文献   

9.
China‘s coastal zone is a region with a highly developed economy that contrasts clearly with the slow paced regular investigation on its natural environment, which cannot keep pace with the requirement of economic development and modem management.Laying a theoretical foundation for the modem management of China‘s costal zone is aimed at.This research focuses on the following processing and analyzing technologies for coastal zone high-resolution remote sensing data: organization and management of large amounts of high-resolution remote sensing data, quick and precise spatial positioning system,algorithms for image fusion in feature level and coastal zone feature extraction. They will form a technical foundation of the system. And, if combined with other research results such as coastal zone remote sensing classification system and its mapping subsystem, an advanced technical frame for remote sensing investigation of coastal zone resource will be constructed.  相似文献   

10.
Stormwater plumes in the southern California coastal ocean were detected by MODIS-Aqua satellite imagery and compared to ship-based data on surface salinity and fecal indicator bacterial (FIB) counts collected during the Bight'03 Regional Water Quality Program surveys in February–March of 2004 and 2005. MODIS imagery was processed using a combined near-infrared/shortwave-infrared (NIR-SWIR) atmospheric correction method, which substantially improved normalized water-leaving radiation (nLw) optical spectra in coastal waters with high turbidity. Plumes were detected using a minimum-distance supervised classification method based on nLw spectra averaged within the training areas, defined as circular zones of 1.5–5.0-km radii around field stations with a surface salinity of S < 32.0 (“plume”) and S > 33.0 (“ocean”). The plume optical signatures (i.e., the nLw differences between “plume” and “ocean”) were most evident during the first 2 days after the rainstorms. To assess the accuracy of plume detection, stations were classified into “plume” and “ocean” using two criteria: (1) “plume” included the stations with salinity below a certain threshold estimated from the maximum accuracy of plume detection; and (2) FIB counts in “plume” exceeded the California State Water Board standards. The salinity threshold between “plume” and “ocean” was estimated as 32.2. The total accuracy of plume detection in terms of surface salinity was not high (68% on average), seemingly because of imperfect correlation between plume salinity and ocean color. The accuracy of plume detection in terms of FIB exceedances was even lower (64% on average), resulting from low correlation between ocean color and bacterial contamination. Nevertheless, satellite imagery was shown to be a useful tool for the estimation of the extent of potentially polluted plumes, which was hardly achievable by direct sampling methods (in particular, because the grids of ship-based stations covered only small parts of the plumes detected via synoptic MODIS imagery). In most southern California coastal areas, the zones of bacterial contamination were much smaller than the areas of turbid plumes; an exception was the plume of the Tijuana River, where the zone of bacterial contamination was comparable with the zone of plume detected by ocean color.  相似文献   

11.
基于线性长波方程和缓变地形近岸波幅格林公式建立了覆盖整个太平洋区域的准实时地震海啸波幅预报系统。系统利用了GPU并行加速技术,可在90 s之内完成太平洋区域32 h的海啸传播计算和中国沿海城市岸段的波幅特征值预报。筛选了自2006年以来的9次发生在太平洋区域,矩震级(Mw)超过8.0且资料丰富的历史地震海啸事件,对预报系统进行了后报检验。结果表明,线性长波模型能够很好的模拟海啸在大洋中的传播过程;格林公式能够较为准确的估算缓变水深和开阔地形条件下的近岸海啸最大波幅,波幅预警准确率可达80%,基本满足海啸预警需求。以2011年日本Mw9.0地震海啸为例,评估了该系统对中国城市岸段的波幅预警能力,结论基本合理。需要注意的是,利用该系统计算对海啸源特别敏感的近场海啸波幅可能产生较大偏差。提出了若要进一步提高定量海啸波幅预警的准确率,可从以下两个方面加强研究和业务实践:一是采用多数据联合反演方法提升海啸源的精度;二是提高格林公式的适用性,或者构建高效的近岸精细化海啸数值预报系统。  相似文献   

12.
论证南海海疆国界线   总被引:2,自引:0,他引:2  
According to a series of important historical maps,i.e.,the Location Map of the South China Sea Islands,the Nansha Islands,Zhongsha Islands,Xisha Islands,Yongxing Island and Shidao Island,and Taiping Island(archived by the Territorial Administration Division of the Ministry of Interior of Republic of China in 1946),and the Administration District Map of the Republic of China published in 1948,the dashed line surrounding the South China Sea Islands represents China's sea boundary in the South China Sea at that time.It was both connected with,and an extension of,the land boundary of China.At that time the dashed line was used to represent the waters boundaries while the solid line was used to represent the land boundary—a universal method used in maps that was then recognized internationally.The above observation provides historical and scientific evidence of China's sea boundary in the South China Sea that is useful for the international maritime delimitation over the South China Sea area.  相似文献   

13.
Studies of offshore wave climate based on satellite altimeter significant wave height(SWH) have widespread application value. This study used a calibrated multi-altimeter SWH dataset to investigate the wave climate characteristics in the offshore areas of China. First, the SWH measurements from 28 buoys located in China's coastal seas were compared with an Ifremer calibrated altimeter SWH dataset. Although the altimeter dataset tended to slightly overestimate SWH, it was in good agreement with the in situ data in general. The correlation coefficient was 0.97 and the root-mean-square(RMS) of differences was 0.30 m. The validation results showed a slight difference in different areas. The correlation coefficient was the maximum(0.97) and the RMS difference was the minimum(0.28 m) in the area from the East China Sea to the north of the South China Sea.The correlation coefficient of approximately 0.95 was relatively low in the seas off the Changjiang(Yangtze River) Estuary. The RMS difference was the maximum(0.32 m) in the seas off the Changjiang Estuary and was0.30 m in the Bohai Sea and the Yellow Sea. Based on the above evidence, it is confirmed that the multialtimeter wave data are reliable in China's offshore areas. Then, the characteristics of the wave field, including the frequency of huge waves and the multi-year return SWH in China's offshore seas were analyzed using the23-year altimeter wave dataset. The 23-year mean SWH generally ranged from 0.6–2.2 m. The greatest SWH appeared in the southeast of the China East Sea, the Taiwan Strait and the northeast of the South China Sea.Obvious seasonal variation of SWH was found in most areas; SWH was greater in winter and autumn than in summer and spring. Extreme waves greater than 4 m in height mainly occurred in the following areas: the southeast of the East China Sea, the south of the Ryukyu Islands, the east of Taiwan-Luzon Island, and the Dongsha Islands extending to the Zhongsha Islands, and the frequency of extreme waves was 3%–6%. Extreme waves occurred most frequently in autumn and rarely in spring. The 100-year return wave height was greatest from the northwest Pacific seas extending to southeast of the Ryukyu Islands(9–12 m), and the northeast of the South China Sea and the East China Sea had the second largest wave heights(7–11 m). For inshore areas, the100-year return wave height was the greatest in the waters off the east coast of Guangdong Province and the south coast of Zhejiang Province(7–8 m), whereas it was at a minimum in the area from the Changjiang Estuary to the Bohai Sea(4–6 m). An investigation of sampling effects indicates that when using the 1°×1°grid dataset, although the combination of nine altimeters obviously enhanced the time and space coverage of sampling, the accuracy of statistical results, particularly extreme values obtained from the dataset, still suffered from undersampling problems because the time sampling percent in each 1°×1°grid cell was always less than33%.  相似文献   

14.
北部湾盆地涠西南凹陷已发现多个碳酸盐岩潜山油田和含油构造,运用岩心、薄片、钻井、测井、地震等资料,对石炭系碳酸盐岩储层特征及主控因素进行了综合分析。研究认为涠西南凹陷碳酸盐潜山主要分布在一号断裂带至二号断裂带附近,其中一号断裂带碳酸盐岩潜山主要为上石炭统黄龙组,岩性为浅灰色灰岩、白云质灰岩、白云岩互层,沉积微相以碳酸盐台地-台缘生屑灰岩滩为主,发育裂缝、溶孔、溶洞等储集空间;二号断裂带碳酸盐岩潜山主要为下石炭统下部石磴子段、孟公拗段,岩性为灰色、深灰色灰岩,沉积微相以台内灰岩滩沉积和台缘生屑灰岩滩为主,发育良好的裂缝型储集层。碳酸盐岩潜山储层发育程度主要受碳酸盐岩沉积环境、地下水活动、古构造应力以及潜山上覆地层岩性等内因和外因诸多因素影响,在这些因素共同作用下,涠西南凹陷碳酸盐岩潜山发育孔隙、裂缝、溶洞等多种储集空间,具备良好的储集条件。  相似文献   

15.
Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows: Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complex- ing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China's coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly.  相似文献   

16.
海南黎安港海草床分布特征、健康状况及影响因素分析   总被引:2,自引:0,他引:2  
通过对黎安港海草资源进行调查,并采用《近岸海洋生态健康评价指南》(HY∕T087-2005)对海草床生态系统健康进行评价。结果表明,黎安港海草种类主要有2科3亚科4属4种,分别为圆叶丝粉草、泰来草、海菖蒲及卵叶喜盐草;海菖蒲分布广泛,其次为圆叶丝粉草及泰来草,海草床分布面积约为0.93 km2,黎安南岸海草分布面积最大,西岸次之,东岸最小。海草平均覆盖度为37.80%。圆叶丝粉草平均密度872.00株/m2,平均生物量150.34 g/m2,泰来草平均密度405.00株/m2,平均生物量62.45 g/m2;海菖蒲平均密度251.00株/m2,平均生物量778.50 g/m2,卵叶喜盐草平均密度6 768.00株/m2,平均生物量70.63 g/m2,2015年黎安港海草床处于健康状态;2018年处于健康状态边缘;2016年、2017年及2019年均处于亚健康状态,主要体现在沉积物环境、栖息地健康以及生物指标存在亚健康,2015年至2019年期间,黎安港海草床的健康状况总体呈现为健康转为亚健康的趋势,主要影响因素有水体交换能力较差、水产养殖活动影响、沿岸围填海工程及其他人为活动影响等。  相似文献   

17.
本文基于琼东南盆地15口钻井和西沙石岛岛礁“西科一井”的钻井资料,结合过井地震剖面,系统分析了琼东南盆地沉降(沉积充填)和西沙岛礁生长速率及其变化特征,探讨了青藏高原隆升与琼东南盆地沉降和西沙岛礁发育之间的耦合关系,三者在发育时间和发育过程上表现出高度的一致性,且南海古海水中Sr同位素组成变化也表现出对青藏高原隆升速率变化很好的响应。相对于深水区,浅水区的沉积物堆积速率及其变化能够更好地反映盆地的沉降速率及其变化。琼东南盆地的沉降(沉积物堆积)和西沙岛礁的发育过程均可以分为3个阶段,分别对应于青藏高原的3个隆升期,时间自老到新分别为:23~16 Ma BP、16~5.5 Ma BP、5.5 Ma BP至今。相比而言,岛礁的发育过程与青藏高原的隆升之间的耦合关系更为密切。在青藏高原的快速隆升期,相应发生盆地沉降(沉积充填或沉积物堆积)和岛礁生长速率的加快,同时对应发生了南海海水87Sr/86Sr比值的增大,说明青藏高原隆升可能是影响琼东南盆地乃至整个南海沉降(沉积充填)、岛礁发育和古海水Sr同位素组成变化的主要因素。  相似文献   

18.
To meet the increasing demand of national spatial database infrastructure construction and application, a concept model of China‘ s coastal zone scientific data platform is established based on the information feature analysis of a compound dataset, consisting of remote sensing data and conventional data. Based on this concept model, the detailed logical database structure and the storage strategy of remote sensing data and their metadata using ArcSDE are designed. The complicated technology of multisources data combination in this research is crucial to the future coastal zone and offshore database construction and practical running, which will provide intelligent information analysis and technological service for coastal zone and offshore investigation, research, development and management.  相似文献   

19.
付金宇  李颖 《海洋通报》2018,(2):235-240
为有效对港区大气污染进行治理、分析船舶尾气,本文详细介绍了一种基于高斯烟羽模型,通过MATLAB模拟仿真模型,其包括实验仿真过程、技术原理及理论模型对船舶尾气扩散进行的研究。该模型是在传统的高斯烟羽模型的基础上,通过对实源像源进行加权选择输入参数;通过矢量合成确定了气体扩散的方向,利用合成后的"风速"进行计算仿真,有效模拟了船舶尾气在港区或者海洋环境中的气体扩散模型。其模型简单且可以有效模拟船舶尾气扩散。并且进一步对后续模型的精确优化进行分析。  相似文献   

20.
The main purpose of this study is to highlight, on the basis of statistical tests, the significant long-term changes of the Mediterranean Sea level, through the analysis of historical tide gauge records. In this framework, 14 tide gauge monthly series selected from the Permanent Service of the Mean Sea Level (PSMSL) database were used. The search for the presence or not of trends within these series, that have a temporal coverage from 59 to 142 years, was carried out using the Mann-Kendall test and the Sen''s slope estimator. The obtained results show that the Split Rt Marjana series are the only ones which does not exhibit a significant trend. The other 13 series show significant increasing trends. This result seems sufficient to suppose the presence, in the past century, of a new climatic phase on the scale of the Mediterranean basin, where the rising sea level is one of the consequences.  相似文献   

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