黄骅港一期工程疏浚物倾倒预选区的浮游生物调查     

王立俊  陈伟斌  李崇德 《海洋科学进展》2000,18(2):61-66

分析了1995年10月黄骅港一期工程疏浚物倾倒预选区浮游生物调查样品和资料.结果表明,调查区的浮游植物是以圆筛藻(Coscinodiscusspp.)等为优势种的近岸广温生态群,浮游动物是以强壮箭虫(Sagittacrassa)等为优势种的近岸低盐生态群,且浮游生物的种类和数量都很丰富.文中还对疏浚施工提出了加强对疏浚船只倾倒到位率监督,根据海洋生物繁殖季节调整疏浚活动等措施,以最大限度地减小因疏浚施工对生态环境造成的危害.  相似文献   

钱塘江河口风暴潮经验预报     

谢亚力  黄世昌 《海洋预报》2006,23(1):54-58

钱塘江河口的风暴潮预报工作可归结为澉浦或乍浦两个单站的预报,这使得经验预报成为可能。利用一种动力线性模型将动力学的线性问题转化为统计学的线性回归模型,通过合理选取预报量及预报因子,并采用正交筛选技术确定每个预报因子所对应的系数,建立经验预报方程。后报结果表明该方法可取得较好的效果。  相似文献   

Improved understanding of petroleum migration history in the Hongche fault zone,northwestern Junggar Basin (northwest China): Constrained by vein-calcite fluid inclusions and trace elements   总被引：1，自引：0，他引：1  

Jian Cao  Zhijun Jin  Wenxuan Hu  Yijie Zhang  Suping Yao  Xulong Wang  Yueqian Zhang  Yong Tang 《Marine and Petroleum Geology》2010

Calcite veins and cements occur widely in Carboniferous and Permian reservoirs of the Hongche fault zone, northwestern Junggar Basin in northwest China. The calcites were investigated by fluid inclusion and trace-element analyses, providing an improved understanding of the petroleum migration history. It is indicated that the Hongche fault behaved as a migration pathway before the Early Cretaceous, allowing two oil charges to migrate into the hanging-wall, fault-core and footwall reservoirs across the fault. Since the Late Cretaceous, the Hongche fault has been sealed. As a consequence, meteoric water flowed down only into the hanging-wall and fault-core reservoirs. The meteoric-water incursion is likely an important cause for degradation of reservoir oils. In contrast, the footwall reservoirs received gas charge (the third hydrocarbon event) following the Late Cretaceous. This helps explain the distribution of petroleum across the fault. This study provides an example of how a fault may evolve as pathway and seal over time, and how reservoir diagenetic minerals can provide clues to complex petroleum migration histories.  相似文献   

广利港河道水位变化及河口拦门沙地形变化分析研究     

林维田  吴永亭  刘建立 《海岸工程》2008,27(3):9-14

根据1984年和2007年两次对广利港航道水深测量的结果,分析研究了广利港航道内的水位变化规律,以及河口拦门沙的地形特征。结果表明广利港航道内水位变化复杂,拦门沙形态改变,水深变浅,原有的航道已经消失。  相似文献   

Infaunal burrow ventilation and pore-water transport in muddy sediments     

D.H. Shull  J.M. Benoit  C. Wojcik  J.R. Senning 《Estuarine, Coastal and Shelf Science》2009

The ventilation of burrows by tube-dwelling benthos is understood to be important in determining rates of exchange of solutes between the sediment and overlying water. However, few models have attempted to link the burrow ventilation behavior of tube-dwelling organisms with their geochemical consequences. The classic cylinder model of bioirrigation in muddy sediments (Aller, R.C., 1980. Quantifying solute distributions in the bioturbated zone of marine sediments by defining an average microenvironment. Geochimica et Cosmochimica Acta 44, 1955–1965) links pore-water processes and burrow sizes and distributions in the sediment by assuming that burrows are fully flushed. The equivalence between the cylinder model and the more commonly used one-dimensional non-local exchange model depends upon this assumption. However, this assumption has seldom been tested in the field. We have extended the cylinder model of bioirrigation to include burrow ventilation activities of organisms. Burrow ventilation is modeled as a simple non-local exchange of burrow water with overlying water. Model simulations indicate that burrow ventilation has a large effect on vertical profiles and fluxes of solute tracers. We collected data on burrow geometry in the field by CT-scanning freshly collected sediment cores. At the same study sites, we measured activity profiles of ²²²Rn, a naturally occurring radionuclide tracer of pore-water transport. With model geometry independently constrained, we tested the model by comparing our model-predicted profiles with measured profiles. Our results demonstrate that burrows in the field are not fully flushed. Our estimated burrow ventilation rates compare favorably with previous laboratory measurements. The inclusion of realistic burrow ventilation in this pore-water transport model strongly affects modeled solute profiles and fluxes. We demonstrate how model parameters can be determined from field samples and present a model that more realistically simulates pore-water transport processes in muddy sediments.  相似文献   

船载ADCP资料的潮流分离方法在厦门港断面重复走航中的应用   总被引：1，自引：0，他引：1  

黄奖  葛勇 《台湾海峡》2009,28(1):123-129

本文运用Candela等提出的潮流分离方法,选用高斯函数作为基函数,采用Matlab程序,首次对厦门港嵩鼓水道的船载ADCP断面重复走航资料进行潮流分离计算．通过对14个计算点的Candela方法计算结果与引进差比关系准调和分析方法计算结果的分析比较可见：（1）两种方法计算所得余流在大、小潮的相关系数分别为0．9882和0．8521,余流相对误差在大、小潮分别为0．065和0．150,而所得余流方向在大、小潮的相关系数分别为0．9982和0．9865,余流方向相对误差在大、小潮分别为0．023和0．027．两种方法计算的余流及其方向的相关性很高（在样本数为14,置信度为α=1％时,相关系数大于0．6610,结果是可信的）,而平均相对误差也很小．（2）对14个计算点的M2、S2、K1、O1、M4和MS4等6个分潮的计算结果（共有84个样本数据）进行分析比较,两种方法计算所得6个分潮的长轴、长轴方向和短轴在大潮的相关系数分别为0．9838、0．8960和0．2335,而在小潮的相关系数分别为0．9656、0．7555和0．2209．这两种方法计算所得6个分潮的长轴、长轴方向和短轴在大潮的平均相对误差分别为0．375、0．071和0．753,而在小潮的平均相对误差分别为0．287、0．254和0．845．两种方法计算的分潮长轴及其方向的相关性很高（在样本数为84,置信度为α=1％时,相关系数大于0．283,结果是可信的）．相应的分潮长轴的相关性略低,但是在样本数为84,置信度为α=5％时,相关系数均大于0．217．可认为在置信度为α=5％时,计算结果是可信的,而平均相对误差则略显较大．综上所述,我们认为采用Candela等的方法对船载ADCP断面重复走航资料进行潮流分离计算是可行的．  相似文献   

福建沙埕港浮游动物群落特征及影响因子   总被引：1，自引：0，他引：1  

朱延忠  陈洪举  刘光兴 《中国海洋大学学报(自然科学版)》2008,38(6)

根据沙埕港2006年1月和4月冬、春季2个航次的调查资料,分析了浮游动物种类组成、优势种、丰度和生物多样性的季节变化,并利用PRIMER统计软件中的PCA、BIOENV和RELATE程序探讨了浮游动物与环境因子的关系.经鉴定共有浮游动物77个种类(含浮游幼虫15类 ).中华哲水蚤(Calanus sinicus)和真刺唇角水蚤(Labidocera euchaeta)是2个航次共有的优势种,桡足幼体在2个航次中也都占优势.与1990年调查相比,浮游动物丰度大幅下降,浮游动物种类组成已发生了较大改变.沙埕港的浮游动物大致可分为河口型类群、沿岸型类群和近海型类群.冬季航次浮游动物的平均总丰度为20.6 ind/m3,春季航次为92. 2 ind/m3,低于福清湾浮游动物同期调查结果.浮游动物总丰度分布均为由湾口向湾顶递减的趋势.春季的浮游动物总丰度和香农-威纳多样性指数均高于冬季,冬季浮游动物生物多样性呈现湾中、西部高,湾口、湾顶低的趋势,而春季浮游动物多样性分布比较均匀.经统计分析,影响冬季和春季浮游动物分布的主要环境因子为盐度、温度.  相似文献   

Theoretical aspects of cap-rock and fault seals for single- and two-phase hydrocarbon columns   总被引：6，自引：0，他引：6  

N.L. Watts   《Marine and Petroleum Geology》1987,4(4)

Cap-rock seals can be divided genetically into those that fail by capillary leakage (membrane seals) and those whose capillary entry pressures are so high that seal failure preferentially occurs by fracturing and/or wedging open of faults (hydraulic seals). A given membrane seal can trap a larger oil column than gas column at shallow depths, but below a critical depth (interval), gas is more easily sealed than oil. This critical depth increases with lower API gravity, lower oil GOR and overpressured conditions (for the gas phase). These observations arise from a series of modelling studies of membrane sealing and can be conveniently represented using pressure/ depth (P/D) profiles through sealed hydrocarbon columns. P/D diagrams have been applied to the more complex situation of the membrane sealing of a gas cap underlain by an oil rim; at seal capacity, such a two-phase column will be always greater than if only oil or gas occurs below the seal.These conclusions contrast with those for hydraulic seals where the seal capacity to oil always exceeds that for gas. Moreover, a trapped two-phase column, at hydraulic seal capacity will be less than the maximum-allowed oil-only column, but more than the maximum gas-only column. Unlike membrane seals, hydraulic seal capacity should be directly related to cap-rock thickness, in addition to the magnitude of the minimum effective stress in the sealing layer and the degree of overpressure development in the sequence as a whole.Fault-related seals are effectively analogous to membrane cap-rocks which have been tilted to the angle of the fault plane. Consequently, all of the above conclusions derived for membrane cap-rocks apply to both sealing faults sensu stricto (fault plane itself seals) and juxtaposition faults (hydrocarbon trapped laterally against a juxtaposed sealing unit). The maximum-allowed two-phase column trapped by a sealing fault is greater than for equivalent oil-only and gas-only columns, but less than that predicted for a horizontal membrane cap-rock under similar conditions. Where a two-phase column is present on both sides of a sealing fault (which is at two-phase seal capacity), a deeper oil/water contact (OWC) in one fault block is associated with a deeper gas/oil contact (GOC) compared with the adjacent fault block. If the fault seal is discontinuous in the gas leg, however, the deeper OWC is accompanied by a shallower GOC, whereas a break in the fault seal in the oil leg results in a common OWC in both fault blocks, even though separate GOC's exist. Schematic P/D profiles are provided for each of the above situations from which a series of fundamental equations governing single- and two-phase cap-rock and fault seal capacities can be derived. These relationships may have significant implications for exploration prospect appraisal exercises where more meaningful estimates of differential seal capacities can be made.The membrane sealing theory developed herein assumes that all reservoirs and seals are water-wet and no hydrodynamic flow exists. The conclusions on membrane seal capacity place constraints on the migration efficiency of gas along low-permeabiligy paths at depth where fracturing, wedging open of faults and/or diffusion process may be more important. Contrary to previous assertions, it is speculated that leakage of hydrocarbons through membrane seals occurs in distinct pulses such that the seal is at or near the theoretically calculated seal capacity, once this has been initially attained.Finally, the developed seal theory and P/D profile concepts are applied to a series of development geological problems including the effects of differential depletion, and degree of aquifer support, on sealing fault leakage, and the evaluation of barriers to vertical cross-flow using RFT profiles through depleted reservoirs. It is shown that imbibition processes and dynamic effects related to active cross-flow across such barriers often preclude quantitative analysis and solution of these problems for which simulation studies are usually required.  相似文献   

用于海洋环境科学的一种新方法--影响因子分析法   总被引：3，自引：0，他引：3  

张丽旭  张小伟 《海洋科学进展》2004,22(1):55-61

用影响因子法对象山港海域叶绿素a与海水理化因子之间关系分析,结果表明：水温、溶解氧(DO)、气温、盐度、化学耗氧量(COD)因子为叶绿素a浓度变化的重要有效影响因子,其中水温、溶解氧因子占主导地位。由于该海域的富营养化,N、P和Si营养盐已经不再是影响浮游植物生长的有效因子。在特定海域资料有限的情况下,影响因子法比普通的相关和灰色系统分析更具有透明性,能够有效剔除无效因子,定量表达各理化因子对叶绿素a的影响程度。用影响因子法可以明确地判断出特定海域各海水理化因子对叶绿素a影响的主次程度及其有效性,从而定量确定出影响叶绿素a浓度的主要因子。  相似文献   

广西珍珠港红树林湿地保护与恢复对策     

何彬元 《湿地科学与管理》2017,(2):47-49

结合广西珍珠港红树林湿地保护与恢复工程项目的实施,分析了项目实施过程中存在的主要问题,探讨了广西珍珠港红树林湿地保护与恢复对策。  相似文献