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辽东湾北部近海海域表层沉积物类型及分布特征   总被引:1,自引:0,他引:1  
对2004年采自辽东湾北部近海海域的16个表层沉积物样品作了粒度分析和粒度参数计算,并进行了沉积物分类和分布特征的研究,结果表明,辽东湾北部近海的表层沉积物粒度主要由粉砂组成,平均含量65.15%,平均粒径5.031。总的特征是在5~10 m等深线,沉积物粒度的平均粒径由东部的4.530、中部的5.050逐渐增大到西部的6.236。沉积物粒度的组成类型由东向西按粉砂质砂→砂质粉砂→粉砂→砂-粉砂-黏土→黏土质粉砂由粗至细排列。  相似文献
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This paper provides a detailed observation of pond hydrodynamics. Bathymetry and aerator deployment largely control the hydrodynamic regime. Aerators drive pond circulation, which is resisted by bottom and bank friction. Hydrodynamic friction is characterized by sediment grain size. One particular pond is offered as a proxy representative of Australian mariculture ponds in general: Pond X. The pond had been stocked with P. monodon at densities in the range 25–35 m−2 about ten times during the period from 1989 to 1995. Observations were made in the year 1996. The site was on the east coast of Australia at 18° south latitude. The location was sheltered by a mountainous offshore island, such that winds effecting the pond averaged 2.3 m s−1. Water exchange occurred at a rate of about 8.3% of pond capacity per day. Pond X was found to be rectangular, 120 m long and 87 m wide. The banks were found to slope between 1:1.5 and 1:7.6, with an average slope near 1:3. The pond was shallowest in one corner, where depth was 834 mm, and drained diagonally with 1872-mm maximum water depth. Aeration was provided by a total of six 1.5-kW machines, comprised of two of the paddlewheel type and four of the propeller-aspirator type. Each machine was found to deliver 200 N of horizontal thrust into the pond water column. The combined effect of the aerators created a circulation current averaging about 11 cm s−1 around the pond periphery. The central region of the pond was found to have a fluctuating velocity of less than 1 cm s−1. The mass-average size of pond soil and sediment was found to vary from 25 μm in the central region to 250 μm at the banks and where the bottom was swept by paddlewheels.  相似文献
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2006年8月对定海湾海域沉积物粒度监测结果:该海域表层沉积物组分不含砾石,并以粉砂为主,海域表层沉积物类型以砂质粉砂(ST)、砂-粉砂-粘土(STY)和粘土质粉砂(YT)为主;该海域表层沉积物粒径分布,呈现由西南向东北变细的趋势;而且,该海域表层沉积物粒度参数的分布,具有一定对应性,其总体特征是,粒径越粗,分选越差,偏态系数越低,峰值也越低.另外,采用"粒度趋势分析"方法,绘制出该海域沉积物净输运趋势概示图.  相似文献
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