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文章从海南岛海湾的数量、分布、海岸地貌类型和成因分类等方面阐述了海南岛海湾的特征。海南岛拥有大小海湾68个,分布在沿海12个市、县,重要海湾有28个;琼北、琼东、琼南及琼西海湾的地貌特征有明显差异;依海湾成因类型,海南海湾分为两个大类,5个亚类,其中原生海湾52个,占76.5%,次生海湾16个,占23.5%;按照海湾的开敞度进行分类,海南岛开敞、半开敞型海湾有55个,占80.9%;封闭、半封闭型海湾13个,占19.1%。在分析海南岛海湾特征基础上对海南岛海湾合理开发利用和保护进行了探讨。 相似文献
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《海洋地质与第四纪地质》2010,(4)
近几十年以来,随着对海湾开发的不断深入,人类活动在海湾的演化过程中逐渐扮演了重要角色,海湾沉积环境发生了异于纯自然状态下演化规律的变化。从海湾沉积物来源、特征、沉积速率和地貌体系4个方面,结合国内外海湾开发利用过程中已呈现出来的问题,初步探讨了人类活动对海湾沉积环境的影响,证明人类在海湾及其周边地区修建各种工程和围海造地等方式,逐渐改变了海湾沉积体系的演化进程。根据现实社会的需求,对海湾沉积领域中急需研究的问题进行了分析,提出急需加强海湾演化规律、寿命和稳定性判据的研究。 相似文献
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研究海湾平衡剖面对理解海湾地貌演变具有重要意义。本文给出了收缩型、扩张型和矩形3种典型海湾平面形态对平衡剖面的影响。建立了海湾长度远小于潮汐波长的短尺度海湾的平衡剖面和对应的时均悬沙浓度的解析解。采用水深平均的水动力方程、泥沙输移方程和地形演变方程的耦合模型对以上3种类型海湾的平衡剖面进行了数值模拟，得到了这3种类型海湾的水面、流速、时均悬沙浓度和平衡剖面的计算结果，并利用水面数值结果确定了海湾水面解析解所含的一个待定常数。研究结果给出了3种不同海湾平面形态所对应的平衡剖面形态:矩形海湾对应斜坡型；收缩型海湾对应下凹型；扩张型海湾对应上凸型。所得海湾平衡剖面和时均悬沙浓度的解析解与数值解一致。 相似文献
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山东半岛南岸潮汐汊道式海湾海洋环境特征及开发功能探讨 总被引：4，自引：0，他引：4
本文以靖海湾、乳山湾、丁字湾为例,论述了潮汐汉道式海湾的自然形态、水文气象、地质地貌之特性,提出要开发利用海湾,首先必须保护海湾,并提出了海湾开发的四项准则:经济效益;促进经济发展的程度;开发项目对国家和地区的重要程度;对环境的影响。据此,靖海湾、乳山湾、丁字湾开发应以港口运输为主,辅以水产生产。 相似文献
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海湾是保护与利用矛盾最突出的区域，是生态环境保护研究关注的焦点区域。“十四五”期间，生态环境管理部门将以海湾为抓手，稳步推进美丽海湾建设。但是目前美丽海湾的相关概念和理论尚不完善，鉴于此，文章在回顾国内外海洋生态环境治理发展历程的基础上，梳理了国内外在海湾生态环境治理方面的主要经验教训，在此基础上完善了美丽海湾的概念以及对概念的科学理解，提出了美丽海湾的行动框架，并对我国建设美丽海湾提出了做好顶层设计，完善法规制度；制定清晰的目标，并层层分解落实；做好陆海统筹，注重以海定陆；注重科技支撑，科技参与决策；发动公众积极参与美丽海湾建设等建议，以期为美丽海湾建设提供技术支撑。 相似文献
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岬间海湾平面平衡形态规律的研究是砂质海岸稳定与演变研究的重要内容。简要回顾了岬间海湾平面形态规律的研究进展,着重介绍了海湾平衡形态的五个模型。通过评述平衡形态模型的优缺点,指出机理分析和经验拟合相结合应该为以后海湾平面平衡形态规律的研究发展方向,并论述了我国岬间砂质海湾平面平衡形态研究的重要意义。 相似文献
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山东半岛北岸与南岸现代岸线差异及其影响因素 总被引：2，自引：0，他引：2
山东半岛北岸、南岸现代岸线差异显著,北岸岸线相对平直,沿岸海积砂体发育,海湾成因类型以次生海湾为主;南岸海积砂体不发育,海湾类型以原生海湾为主。造成这种差异的因素包括地质构造、地形、海水动力条件、全新世相对海面变化及其河流地貌响应等。 相似文献
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岬间海湾岸线平衡形态神经网络模型 总被引：1，自引：0，他引：1
讨论了目前海湾岸线平衡形态经验模型存在的不足之处。从沿岸输沙公式入手,阐述了平衡岸线的机理模式,重新定义了平衡海湾的“下岬角”,给出了模型参数与主波向的具体计算方法,并以华南典型海湾为学习样本,建立了岸线平衡形态的神经网络模型。通过模拟海湾与实际稳定海湾——乌场湾间的对比分析,表明所建神经网络模型是较抛物模型更为理想的平衡岸线模型。 相似文献
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The rise or fall trend of the sea level along the coast of East Asia is estimated with different computational methods based on sea‐level data of longer time series collected from 45 tide gauge stations there. The results show that the relative sea level, on average, has been rising along the coast of the whole of East Asia from the early 1950s to the early 1990s. The regional change of sea‐level rise or fall is greater. The sea level along the coast of China, except along the Shandong Peninsula, is rising; the sea level along the coast of the southern islands of Japan and the southern Korean peninsula, as estimated by several methods, is mostly rising, but the rate of rise is very small. The difference between the results estimated in this study and the corresponding results of Barnett along the coast of East Asia is significant. This is mainly because the number of the stations selected by Barnett is relatively small, and the selected stations are concentrated at the southern and northern ends of the region, without data in the middle of the region. The effect of the estimating methods is smaller. 相似文献
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The process of upwelling/sinking and associated sea level variations are seen as a response of coastal ocean to pure wind stress forcing. Further,precipitation and monsoonal floods, apart from the marine meteorological parameters, are expected to influence the sea level fluctuations along the coast. This study comprises determining the sea level from the various parameters together with the pure wind stress forcing, which is compared with the observed cycle. However, it is found that there is considerable difference between the computations and observations. This suggests that the sea level is dependent not just on the local forcing alone, but also on the induced background circulation as well. For example, the sea level changes along the east coast of India, particularly the northern region, are more sensitive to freshwater discharge from various rivers joining the Bay of Bengal. This is due to more frequently occurring pre- and postmonsoon cyclonic storms and the associated surges in the Bay of Bengal as compared to the Arabian Sea. Hence the salinity effects are particularly important in the coastal waters off the east coast of India during monsoon months (June-September). For the west coast of India, however, it is expected that the large-scale coastal circulation may play a role in determining sea level changes in addition to other forcings. The salinity effects are negligible along the west coast in the absence of any major river systems that join the Arabian Sea. The local advection currents caused by the offshore directed freshwater discharge from various estuaries joining the coastal bay also seemed to influence the sea level. In order to elucidate the essential dynamics involved and to study the effect of the remote forcing, a three-dimensional baroclinic, nonlinear numerical model is used with appropriate open boundary conditions. The local effect of the current has been incorporated in the west coast model by means of opening a channel at Cochin through which the rainwater is carried away to the model ocean. The low saline plume, cascading from north along the east cost of India, has been incorporated in the east coast model through a proper forcing applied at the northern boundary of the model. With the inclusion of these remote forcings in the models, the disagreement between the simulations and the observations is minimized. 相似文献
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The process of upwelling/sinking and associated sea level variations are seen as a response of coastal ocean to pure wind stress forcing. Further,precipitation and monsoonal floods, apart from the marine meteorological parameters, are expected to influence the sea level fluctuations along the coast. This study comprises determining the sea level from the various parameters together with the pure wind stress forcing, which is compared with the observed cycle. However, it is found that there is considerable difference between the computations and observations. This suggests that the sea level is dependent not just on the local forcing alone, but also on the induced background circulation as well. For example, the sea level changes along the east coast of India, particularly the northern region, are more sensitive to freshwater discharge from various rivers joining the Bay of Bengal. This is due to more frequently occurring pre- and postmonsoon cyclonic storms and the associated surges in the Bay of Bengal as compared to the Arabian Sea. Hence the salinity effects are particularly important in the coastal waters off the east coast of India during monsoon months (June-September). For the west coast of India, however, it is expected that the large-scale coastal circulation may play a role in determining sea level changes in addition to other forcings. The salinity effects are negligible along the west coast in the absence of any major river systems that join the Arabian Sea. The local advection currents caused by the offshore directed freshwater discharge from various estuaries joining the coastal bay also seemed to influence the sea level. In order to elucidate the essential dynamics involved and to study the effect of the remote forcing, a three-dimensional baroclinic, nonlinear numerical model is used with appropriate open boundary conditions. The local effect of the current has been incorporated in the west coast model by means of opening a channel at Cochin through which the rainwater is carried away to the model ocean. The low saline plume, cascading from north along the east cost of India, has been incorporated in the east coast model through a proper forcing applied at the northern boundary of the model. With the inclusion of these remote forcings in the models, the disagreement between the simulations and the observations is minimized. 相似文献
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粤西海岸全新世中期以来海平面升降与海岸沙坝潟湖发育过程 总被引：3，自引：0，他引：3
沙坝湖海岸是一种重要的海岸类型。文章论述了粤西海岸全新世中期以来在海平面升降影响下沙坝湖地貌的发育过程,得出如下结论：距今7000a至5000a．海平面曾上升至＋4m,由于大陆架泥沙的向陆堆积,形成了揭湖拦湾沙坝的后缘高突部分：以后海平面逐步下降至现今位置,它所形成的海退沙楔发育成低矮的向海沙坝和海滩;距今2000a,海平面趋于相对稳定;现今海平面微升,出现了海岸侵蚀。文章还对该地在海平面升降影响下的海岸泥沙运移机制以及海岸高海面堆积和现今海岸侵蚀现象作了解析。 相似文献
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The wave climate at the Maui site off the west coast of the North Island and off the east coast of Great Barrier Island to the east of the North Island are examined. This is done by means of average wave spectra derived from a 2‐year database, acquired from Waverider buoy measurements made over 1980 and 1981. The average spectra provide information about the individual sea states which characterise the wave climate, and show that on average the sea state on the east coast is less energetic than it is on the west coast. Further, it is seen that this difference results largely from a dominant and persistent long‐period south‐westerly swell of 12.4 s period which is present at the Maui location but absent from the Great Barrier Island seas. 相似文献
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通过实地调查和资料搜集,对丹麦日德兰半岛西海岸典型岸段的地貌类型和研究现状进行了总结。丹麦日德兰半岛西海岸岸线长度约为470km,海岸类型可以分为无障壁海岸和有障壁海岸2大类。无障壁海岸以沙丘为主,并有海蚀崖,主要分布在斯卡恩(Skagen)到布劳万角(Bl?vands Huk);有障壁海岸地貌类型以障壁岛—潟湖、盐沼为主,主要分布在布劳万角到勒姆岛(R?m?),并向南进入德国。丹麦西海岸北部属于冰后期地壳回弹上升区,向南地壳回弹幅度逐渐减弱,至Ringk?bing峡湾地区变为地壳稳定区,再向南地壳变为下降区,因此,全新世地层中分别记录了不同的相对海面变化信息。距今7 150a以来,北部的Skagen岬角地区的相对海面下降了16~25m;Skallingen地区过去5 000a间海面在现代海面附近波动,其后侧Ho Bugt盐沼地区4 000a以来相对海面上升了4m;过去8 000a间,R?m?障壁岛的相对海面上升了15m。欧洲学者在丹麦西海岸地区取得的典型成果包括:海面变化重建(包括海面变化标志点、泥炭层压实校正、定年等)、全新世地质环境演化、开放潮坪现代沉积定量研究等,为海岸带研究提供了有益参考。 相似文献
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O. P. Singh 《Marine Geodesy》2013,36(3):205-212
The Bangladesh coast is threatened by rising sea level due to various factors. The results based on the analysis of past 22 years of tidal data of the Bangladesh coast reveal that the annual mean tidal level in the eastern Bangladesh coast is rising at an alarmingly high rate of 7.8 mm/year, which is almost twice the observed rate in the western region. This type of sea level trend seems to be the result of changing local conditions like increased precipitation and land subsidence during the recent decades. It seems that the higher rate of land subsidence in the eastern Bangladesh coast is the main causative factor for the steeper sea level trends there. The differential sea level trends show that the subsidence component in the sea level rise may be as high as 4 mm/year in the eastern Bangladesh coast. However, this needs to be verified with actual geological observations. 相似文献
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Spatial Variation of Sea Level Trend Along the Bangladesh Coast 总被引：1，自引：0，他引：1
O. P. Singh 《Marine Geodesy》2002,25(3):205-212
The Bangladesh coast is threatened by rising sea level due to various factors. The results based on the analysis of past 22 years of tidal data of the Bangladesh coast reveal that the annual mean tidal level in the eastern Bangladesh coast is rising at an alarmingly high rate of 7.8 mm/year, which is almost twice the observed rate in the western region. This type of sea level trend seems to be the result of changing local conditions like increased precipitation and land subsidence during the recent decades. It seems that the higher rate of land subsidence in the eastern Bangladesh coast is the main causative factor for the steeper sea level trends there. The differential sea level trends show that the subsidence component in the sea level rise may be as high as 4 mm/year in the eastern Bangladesh coast. However, this needs to be verified with actual geological observations. 相似文献
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根据东亚沿岸４５个水位观测站的长序列水位资料，用不同的计算区域平均海平面升降的方法，估计了该区海平面升降趋势。结果表明，从本世纪５０年代初至９０年代初，整个海区平均而言海平面呈上升趋势。海平面升降的区域性变化较大：中国沿岸除山东半岛外，其他海区平均是上升的，在日本群岛南部和朝鲜半岛南部沿岸，由几种方法得出的结果多数是上升的，但上升幅度很小。本文对东亚沿岸海平面升降的估计结果与Ｂａｒｎｅｔｔ的相应估计差别较大，其主要原因是Ｂａｒｎｅｔｔ选站较少，且选的站集中在该区南北两端，中间部分无资料；估计方法虽有影响，但属次要的。 相似文献
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基于海洋站潮位观测和中国沿海海平面变化影响调查等数据,分析了辽东湾沿岸海平面变化及海岸侵蚀状况,并定量评估了未来海平面上升情景下,辽东湾两岸典型沙质海岸侵蚀影响和沙滩养护投入。分析预测和评估结果表明:1980-2017年,辽东湾沿海海平面上升速率为3.0 mm/a,其中辽东湾东岸沿海海平面上升速率明显高于西岸。2009-2017年,辽宁营口白沙湾、绥中网户、绥中南山港和绥中团山气象观测场岸段后退和下蚀较为严重,部分岸段滩肩蚀退达2～3 m/a。预计2100年,辽东湾沿海海平面上升幅度在20～48 cm之间,由海平面上升引发的辽东湾海岸侵蚀土地损失为23.1 km2,土地经济损失为1410万元。为减缓海岸侵蚀,旅游沙滩和一般沙滩养护总投入分别为11亿元和46亿元,全岸段养护成本较高,应选取旅游沙滩等重点岸段进行养护。 相似文献