【作者】 陈可锋；

【导师】 喻国华；

【作者基本信息】 南京水利科学研究院 ， 港口、海岸及近海工程， 2008， 博士

【摘要】 海岸带陆海相互作用（LOICZ,Land-ocean Interactions in the Coastal Zone）,在近几年中成为海岸带研究的热点以及全球变化中的研究前沿。自上个世纪90年代以来,各国相继开展了陆海相互作用（LOICZ）及其相关研究。江苏海岸带受季风气候控制,处于北亚热带向暖温带过渡的地带,兼受海洋性和大陆性气候双重影响,地貌沉积类型丰富。近一个半世纪以来废黄河三角洲海岸数十公里的岸线后退和上百公里尺度的辐射沙洲的逐渐形成,在国内乃至全世界都是十分罕见的。江苏海岸是区域内开展LOICZ研究的理想场所。黄河北归前河口地区突出岸段的岸线在目前岸线以外20余km,且岸外有广阔的水下三角洲浅水区。经过一个半世纪的调整改造,水下三角洲已经被夷平,目前-15m等深线已内移至距岸约4km。由于废黄河三角洲及其水下三角洲被侵蚀的泥沙,在海流的携带下向南搬运堆积,加上长江口北上泥沙流在此带堆积,南部海岸继续淤涨,向海推进最远约20km。岸线和水下地形的剧烈改变对潮波传播的局部影响不容忽视。目前尚无实测资料对比和模拟研究证实这种变化的过程及其趋势。近期对辐射沙洲区近岸水道、沙洲和岸滩稳定性研究发现,近半个世纪以来,辐射沙洲南翼的小庙洪、网仓洪、烂沙洋和黄沙洋等水道及其之间的沙洲普遍存在逐渐向南偏移的趋势。考虑到废黄河三角洲海岸作为辐射沙洲地区的主要泥沙源,同时,南黄海旋转潮波需经废黄河三角洲岸外向南传播进入辐射沙洲区,构成辐聚辐散的潮流格局。黄河北归150年来废黄河三角洲海岸20余km的侵蚀后退以及侵蚀泥沙的逐渐减少对辐射沙洲区两大潮波系统强弱对比和区域泥沙供给条件的可能影响。可以推测废黄河三角洲海岸整体大范围后退对由北向南传播的旋转潮波阻碍作用有所减弱,从而使旋转潮波相对加强。两大潮波系统辐聚形成的辐射沙洲近期动态表现出主轴南移趋势与废黄河三角洲侵蚀后退后北部旋转潮波加强可能有成因上的联系。另外,东中国海平均海平面在此期间数十厘米的上升也是值得考虑的因素。海平面上升引起的黄海潮波系统的变化,势必影响到辐射沙洲趋势性演变的宏观背景和江苏海岸的侵蚀,但是否是影响辐射沙洲趋势性演变的主要动力驱动因素,以及海平面上升与江苏海岸侵蚀的关系,其作用的强度有多大等都需要进一步的研究。本项研究通过大量的实测资料和数值模拟的结果,分析了江苏海岸水动力和岸滩演变的特点;在恢复黄河北归以来,苏北黄河三角洲海岸不同发育阶段的岸线位置和水下地形的基础之上,通过所建立的潮波数学模型,研究了在苏北黄河三角洲不同演变阶段南黄海潮波系统的特征及其变化,分析了江苏海岸演变与潮波系统变化的对应关系和相互作用;分析了海平面上升对江苏海岸潮波系统的影响,探讨了控制辐射沙洲趋势性演变的主要驱动力。得出如下系列成果:（1）岸线和水下地形的变化导致江苏沿海分潮振幅的变化,大致以废黄河口为界,以北振幅减小以南振幅增大,其中以辐射沙洲内海的振幅变化最大;岸线的后退使得M₂、S₂分潮无潮点位置也不断向西南方向移动。（2）海平面上升后分潮的振幅将随之而变大,但在部分区域,分潮振幅随着海平面上升而减小;无潮点相对于现有的无潮点位置均向东南方向偏移;海平面上升导致的潮差变化,大致以吕四为界,以北随着海平面上升,分潮的振幅不断增大,以南振幅减小,其中在废黄河口附近的增幅也相对较小;潮差增大幅度最大的地区刚好是岸滩侵蚀最快的地区,海平面上升与岸滩侵蚀存在很好的对应关系。（3）随着江苏海岸线后退,废黄河口水下三角洲夷平,南黄海旋转潮波得到进一步的加强。水动力加强的区域逐渐向辐射沙洲偏移,也即水动力的主轴方向明显向南偏移了,而这种水动力的主轴向南偏移,就有可能是导致辐射沙洲整体南移的主导因素。（4）随着海平面上升速率的加快,海平面上升引起的沿岸潮差、近岸流速的增大以及风暴潮的加剧,使得海平面上在海岸侵蚀作用中越来越大,江苏海岸岸滩侵蚀的将不断加剧。更多还原

【Abstract】 Land-ocean Interactions becomes the hot spot of the research on the coastal zone and the forefront in global change research,in the past few years.from 1990’s,the Land-ocean Interactions research and relevance studies had been carried out consecutively in every country.The Jiangsu coastal zone is controlled by the monsoon climate,lies in north subtropics zones to warm temperate zone transition.It is impacted by marine and continental double of climate and it’s topography sediment types is rich, in that case,Jiangsu coastal zone is the ideal zone to start the LOICZ studies.Before the yellow river northward motion,the outstanding coast region was far more 20km away from recent coastline,meanwhile,it had extensive undersea delta out of estuary area.After adjusted and reformed for one and half century,the undersea delta is already deplanation and -15m depth line moves inwarda and has nearly 4 km distance from recent coastline.The silt from the Yellow river Delta and their undersea delta,moves southward and silt in here following the current,meanwhile,the sediments form the Yangtze River north part also silt here,the southern part coast continues becoming silted up with the most distant about 20 km,moving forward to the sea.The effect that acute change of the coastal line and undersea landform leading to tide wave propagation and the interaction between tidal wave system and coastal morphology are ignoredIn the recent research,we find the trends that the water channel and sandbar in north Jiangsu coast offsets gradually to south,such as Xiaomiaohong channel、LanshaYang channel and the south part of the radiation sandbar.consideing that Yellow river Delta coast is the main silt source and the revolving wave tide in Yellow sea spreads southward entering radiate sandbar area,passing the Yellow river delta,We can guess that the revolving tide wave reinforces causing by the corrodes recession of the old Yellow river delta may be relate with the chief axis of the channel sandbar system moving to south.Average sea level rise by ten centimeters in East China Sea is also worth to be considered in here.The Yellow Sea tidal wave system’s causesd by the sea level rise change must affect the macroscopic background,but whether is the prime motors actuation factor which causes radiate sandbar trendy enolution,as well as relation between sea level rise and Jiangsu coastal erosion,its function’s intensity and so on need to be far more researchedBy the large amount of reality measures data and numerical results,hydraulic and beach evolution characteristic of Jiangsu coast had been analyzed.Basing on restoring waterfront position and the undersea topography of destroy Yellow River delta coast in different developmental stage,since the Yellow River turning over to the northern,through establishing the wide range tidal wave mathematical model and the partial tidal current mathematical model,,the Yellow Sea tidal wave system’s characteristic and the change in delta different evolution stages have been studied, correspondence relation and coactions between delta coast evolution and tide wave system’s change have been analyzed;Jiangsu coastal tide wave system effecting by sea level rise have been studied,the driving force controlling evolution trend of radiation sandbar also have been discussed.Reach as follows series achievement:（1） The coastline and undersea landform change have lead the amplitude change of littoral partial tide in Jiangsu,which takes Yellow River mouth as boundary basically,to north,the amplitude is enhanced,to south the amplitude is diminishable, amplitude change in the radiate sandbar inner sea is maximum;Tide counting positions of the M₂、S₂ partial tide move unceasingly to southwest direction following the coastline recession.（2） With sea level rise,the partial tide amplitude will be increased,but diminish in some part area;meanwhle tide counting position of partial tide moves unceasingly to southeast direction;Tide amplitude change causing by sea level rising can be taken the Lvsi port as the boundary,to the north,partial tide amplitude enhances unceasingly,and to south it diminishes,especially in destroyed Yellow river it has less enhancement;The region where has the largest increasing partial teide amplitude also the palce which has the quickest erosion rate.sea level rising has a good relation with the beach erosion.（3） With the Jiangsu coastline retreating,the destroyed Yellow River undersea delta deplanation,revolution tide in south Yellow sea gets strengthen,the area that water driving force reinforcement is also that dynamic water chief axis direction has moved obviously to south clearly gradually to radiation sandbar excursion.This offsets of dynamic water chief axis may be the dominant factor that the radiation sandbar entirety moves to south.（4） With the rate of sea level rise being accelerated,the littoral tide amplitude arousing,off-shore flow rate enhancing aggravate as well as storm is damp,it effect in coast erosion is more and more bigger,the erosion of the coastal beach in Jiangsu coast is aggravate unceasingly更多还原