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121.
成山头海域潮流能资源可开发量评估   总被引:1,自引:0,他引:1  
武贺  王鑫  韩林生 《海洋与湖沼》2013,44(3):570-576
针对潮流能资源较丰富的成山头外海域,利用FVCOM数值模式,在良好模拟该海域潮流场的基础上,运用能量耗散原理,对该海域的潮流能资源可开发量进行了评估。结果表明,在转换装置的拖拽系数为0.07时,面积为27km2的成山头近岸海域的可开发潮流能资源约为17.9MW,其中大潮期间的可开发量高达37.7MW,而小潮期间则为7.3MW。在此条件下,该海域大潮期间涨急和落急时刻的流速分别减小了40%和38%,但发电装置对潮汐的影响较小,在成山头顶端的高潮潮位仅下降了4cm。  相似文献   
122.
Experiments with a climate model were conducted under present day and last glacial maximum conditions in order to examine the model’s response to a vertical mixing scheme based on internal tide energy dissipation. The increase in internal tide energy flux caused by a 120 m reduction in sea level had the expected effect on diffusivity values, which were higher under lower sea level conditions. The impact of this vertical diffusivity change on the Atlantic meridional overturning is not straightforward and no clear relationship between diffusivity and overturning is found. There exists a weak positive correlation between overturning and changes to the power consumed by vertical mixing. Most of the climatic response generated by sea level change was not related to alterations in the internal tide energy flux but rather to the direct change in sea level itself.  相似文献   
123.
为了弄清江苏沿海滩涂利用模式分布情况,定量分析其时空变化趋势,本文基于Google Earth Engine云计算平台和Landsat卫星遥感影像数据,结合随机森林分类方法,通过机器学习建立了滩涂利用模式自动识别分类方法,样本训练后识别准确率达93%以上.利用该方法提取了2002年、2014年和2019年江苏沿海的土地...  相似文献   
124.
李鹏  杨世伦 《海洋与湖沼》2014,45(1):126-133
为研究潮间带和潮下带的水、沙、盐交换,于2006年6月25~28日(夏季大潮)和2006年12月29日~2007年1月4日(冬季中-大潮和小潮)在长江口九段沙一典型潮沟的固定点利用OBS-3A和ADP-XR进行了水深、浊度、盐度、流速流向剖面和回声强度观测。结果和结论为:(1)夏季大潮、冬季中-大潮、冬季小潮的潮周期垂向平均流速分别为26.5、15.9和8.4 cm/s,夏、冬季观测到的最大流速分别为84 cm/s和35 cm/s。(2)夏季盐度变化范围为0.65~4.91,平均盐度2.14;冬季盐度变化范围为3.5~10.3,中-大潮和小潮平均盐度分别为6.26和7.98。(3)高悬沙浓度出现在涨潮初期和部分落潮末期的低水位阶段;涨潮阶段的平均悬沙浓度是落潮阶段的1.11~7.0倍。(4)涨、落潮阶段的水体和盐输运量大体上趋于平衡;(5)无论是冬夏季或大小潮,潮沟在潮周期内的净输沙方向均指向陆,即落潮输沙量小于涨潮输沙量(平均小40%);平均每个潮周期的净输沙量为6102 kg,结合潮盆面积推算的潮周期沉积速率为0.0112 mm/tide,或8.2 mm/a。  相似文献   
125.
The effects of tidal forcing on the biogeochemical patterns of surface water masses flowing through the Strait of Gibraltar are studied by monitoring the Atlantic Inflow (AI) during both spring and neap tides. Three main phenomena are defined depending on the strength of the outflowing phase predicted over the Camarinal Sill: non-wave events (a very frequent phenomenon during the whole year); type I Internal wave events (a very energetic event, occurring during spring tides); and type II Internal wave events (less intense, occurring during neap tides).During neap tides, a non-wave event comprising oligotrophic open-ocean water from the Gulf of Cádiz is the most frequent and clearly dominant flow through the Strait. In this tidal condition, the inflow of North Atlantic Central Water (NACW) provides the main nutrient input to the surface layer of the Alboran Sea, supplying almost 70% of total annual nitrate transport to the Mediterranean basin. A low percentage of active and large phytoplankton cells and low average concentrations of chlorophyll (0.3–0.4 mg m−3) are found in this tidal phase. Around 50% of total annual phytoplankton biomass transport into the Mediterranean Sea through the Strait presents these oligotrophic characteristics.In contrast, during spring tides, patches of water with high chlorophyll levels (0.7–1 mg m−3) arrive intermittently, and these are recorded concurrently with the passage of internal waves coming from the Camarinal Sill (type I internal wave events). When large internal waves are arrested over the Camarinal Sill this implies strong interfacial mixing and the probable concurrent injection of coastal waters into the main channel of the Strait. These processes result in a mixed water column in the AI and can account for around 30% of total annual nitrate transport into the Mediterranean basin. Associated with type I internal wave events there is a regular inflow of large and active phytoplankton cells, transported in waters with relatively high nutrient concentrations, which constitutes a significant supply of planktonic resources to the pelagic ecosystem of the Alboran Sea (almost 30% of total annual phytoplankton biomass transport).  相似文献   
126.
互花米草Spartina alterniflora自1979年引入至今,已在我国海岸带大范围扩张并对盐沼湿地生态系统产生了很大影响.本研究以附着生物藤壶为例,研究了互花米草扩张对附着生物的影响.通过对5个断面共28个样方的米草植株、附着藤壶以及藤壶在互花米草上的最大附着高度调查,获得结果如下:藤壶在互花米草滩上的附着范围位于潮沟两侧,且呈宽度约为5 m的带状分布;潮沟规模越大,其向陆方向的延伸范围越宽;每个站位藤壶附着的相对最大高度都位于同一水平.附着藤壶均为白脊管藤壶Fistulobalanus albicostatus,平均干重237±69g·m-2,大部分藤壶直径在2~10mm之间.互花米草的平均干重为981±81g·m-2,潮沟附近互花米草高壮但密度较小,远离潮沟互花米草矮小但密度较大.分析表明,互花米草为藤壶提供了附着基质,并影响藤壶在潮间带的平面分布格局(尽管藤壶的生态位保持不变).影响白脊管藤壶分布特征的原因主要是海水浸没时间的差异;负地形的浸没时间更有利于藤壶的附着和生存;另外潮沟较高的潮水流速除了利于白脊管藤壶幼体的附着外,还可以通过水流的涨、落为其带来充足的食物.  相似文献   
127.
对湛江东海岛潮间带表层沉积物中酸可挥发性硫化物(AVS)和同步提取重金属(SEM)的含量及其分布进行了研究。研究表明,东海岛潮间带表层沉积物中AVS含量夏季平均为0.449μ mol/g,冬季为1.816μ mol/g,大多数站位AVS含量冬季高于夏季;AVS平均含量总体呈南、北区较高,东、西区较低的区域分布规律。潮区沉积物可提取重金属SEM总量夏季在0.56μ mol/g~4.60μ mol/g之间,冬季处于0.65μ mol/g~2.21μ mol/g之间;各重金属平均含量大小为ZnCrPbCuCd,其中Cd含量占SEM总量不到1%,Zn含量则在70%以上,SEMZn是控制着SEM分布的主要模式。联合利用(∑SEM/AVS)与(∑SEM-AVS)法和生物毒性阈值法综合评估重金属对沉积环境的影响,东海岛潮间带大部分区域沉积物中(∑SEM-AVS)处于0~5之间,重金属潜在生物毒性较强的区域为通明海区(7号站和8号站所在),具有较强潜在生物毒性的重金属为夏季通明海区的Zn。  相似文献   
128.
叶海全 《东北测绘》2014,(2):142-143,147
基于无人机的特点,快速准确获取滩涂海域航摄影像,利用PixelGrid-UAV模块影像快速处理系统,结合历史影像数据,实现了滩涂海域资源的动态监测。  相似文献   
129.
In this paper we present a method for computing the equilibrium structures and various physical parameters of a primary component of the binary system assuming that the primary is more massive than the secondary and is rotating differentially according to the law of the w2 = b0 + b1 × s2 + b2 × s4, w being the angular velocity of rotation of a fluid element distant s from the axis of rotation and b0, b1, b2 suitably chosen numerical constants. This method utilizes the averaging approach of Kippenhahn and Thomas (1997) and the concept of Roche equipotentials in a manner earlier used by Mohan et al. (1997) to incorporate the effects of rotation and tidal distortions on the equilibrium structures of certain rotationally and tidally distorted stellar models. The use of the method has been illustrated by applying it to obtain the structures and some observable parameters of certain differentially rotating and tidally distorted binary systems whose primary component is assumed to be a white dwarf star.  相似文献   
130.
A two dimensional implicit finite volume scheme for solving the shallow-water equations is developed. The effects of the Coriolis force, surface wind stress, and waves are included. A non-uniform rectilinear forward staggered grid is used with Cartesian coordinates. The time integration is performed using the Euler implicit technique. The convective flux is treated using the deferred correction method. The viscous terms are discretized using a second order central difference approximation. The SIMPLE (Semi-Implicit Method for Pressure-Linked Equations) algorithm is used for coupling the velocity components and the water elevation gradient for the water level correction. The system of equations is solved sequentially using the Strongly Implicit Procedure (SIP). To simulate wave driven current, a phase averaged wave model is used first to simulate wave transformation and calculate radiation stresses. The performance of the developed model is validated for different sources of external forces and different combinations of boundary conditions. The validation cases include tidal circulation in a harbor and wave induced currents behind a breakwater parallel to the coastline. The model is finally applied to simulate the flow pattern in a closed artificial lagoon and along the coastline near Damietta Port located along the Northern coast of Egypt. Results of the developed model agree well with the published results for the considered cases.  相似文献   
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