【作者】 陈志娟；

【导师】 拾兵； 李希宁；

【作者基本信息】 中国海洋大学 ， 水力学及河流动力学， 2008， 硕士

【摘要】 20世纪80年代后期,随着黄河口向东延伸摆动,扩散至孤东海域的黄河入海泥沙数量急剧减少,致使孤东海域成为严重的侵蚀区。尽管1996年以后黄河改由清8出汊入海,但由于连年枯水少沙,在孤东垦东五及新滩油田,海岸线发生了大幅度的后退。1999年小浪底水库投入运用,自2002年起黄河进行了六次调水调沙,河口地区水沙特性发生了重大变化。针对小浪底水库运用后黄河来水来沙变异的新情况,科学分析黄河口现行流路泥沙输移、岸滩演变规律,预测黄河口改走北汊后河口区潮流场的时空变化特征,以及对改善孤东油田海堤冲刷现状所起的作用,将具有重要的科学意义。本文在分析河口地区风场及海洋动力条件的基础上,利用SMS(Surface-Water Modeling System)进行建模,采用无结构六点元网格,开展黄河河口及其周边大范围海域数值模拟研究,利用实测资料进行校核模型,证明SMS水动力模型能够初步达到复演和预测整个黄河三角洲附近海域潮流场、潮位、入海泥沙扩散规律、泥沙淤积形态和流路延伸发展趋势等方面的要求。利用校核后的模型模拟黄河口改走北汊后的潮流场及泥沙的时空变化,通过计算得出以下结论:黄河改走北汊河后,由于海洋、地形等条件的变化,泥沙输移将出现新的特点。入海泥沙扩散,沿垂直海岸方向范围小,沿海岸方向范围大,符合往复式潮流椭圆分布特征;同时,由于受柯氏力及潮流的影响,泥沙向河口两侧扩散,衰减距离不对称。黄河改走北汊河,按照近几年的水沙条件及河口位置,在行河初期对东营港不会有淤积影响;同时,按照计算结果推算,随时间的推移,河口在海洋动力以及柯氏力的作用下,除初期向东偏北方向,其后河口逐渐向东南方向延伸发育,口门离东营港的距离越来越远,入海泥沙对东营港的影响将越来越小。改走北汊后的流路将从孤东油田南围海堤以南入海,泥沙的扩散将对孤东油田产生直接的影响。孤东海区因地理位置的不同平均年淤积厚度在3-18cm之间,并且随着2002年后调水调沙入海沙量的增加,每年淤积厚度将增大。这将改善孤东油田堤角被淘空的现状,提高孤东大堤的安全性。同时,随着行水年限的增长,河口的推进将淤出大片土地,这将使部分海上石油开采的油田变为陆上开采。论文最后给出了建议。即:在做好来水来沙预报、加强河势与海洋动力观测、预报和科学技术研究工作的基础上,应进一步掌握河口演变规律,在不影响规划流路使用和总的行河年限的前提下,兼顾油田的发展和滩区油田的开采,科学地确定改走北汊的时机。更多还原

【Abstract】 In the late 1980s, the sediment yields diffused to the Gudong sea area decrease drastically with the Yellow River estuary extending to the east, which make the sea area become a serious eroded area. Though the Yellow River changes the estuary to the Qing 8, as a result of low water and few sands in successive years and a lot of oil fields in GuDong, coastal line backs off seriously. In 1999, the Xiaolangdi Reservoir was put into use. The characteristic of water and sediment in the estuary area changes remarkably as a result of 6 times regulating water-sediment from the 2002. According to the characteristics of the incoming water and sediment affected by the Xiaolangdi reservoir, and considering the new case that Yellow River changes its main channel to the Beicha river, this will be important scientific significance for analyzing the sediment transport and the evolvement of the shoal, predicting the tidal current changes with time and space, improving the present erosion status for Gudong bank.Based on analyzing wind field in the estuary and the ocean hydrodynamic condition, this paper used the Surfer Water Model System (SMS), set up a two-dimensional triangular (three -corner and three-mid side nodes) elements model for simulating the Yellow River Estuary and the extension sea area around it, and verified the calculating results by actual material, proved the SMS is of capable of simulating and forecasting the flow fields, tide level, and sediment transport and coastal shoal evolvement of Yellow River Delta Area.This paper gets the following conclusions by calculating the checked model that has been used to simulate the tidal current and the sediment transport in the case that the Yellow River estuary alter to the Beicha river.The calculating data show new characteristics for sediment transportation as a result of changing ocean dynamic condition and terrain in condition that Yellow River estuary changes to the Beicha river. The range of the sediment transported into sea become narrow in vertical seacoast and widen along the seacoast which is consistent of the reciprocating tidal current ellipse character. At the same time, the sediment will accumulate to both sides of the estuary and the attenuation isn’t symmetry affected by Criolis’force and tidal current.According to the water and sediment condition and estuary position in recent years, the Dongying harbor will be not filled up in the early stage. Because new estuary is affected by the ocean hydrodynamic condition and the Criolis’force with the passage of time, it will extend to ENE in the early stage and then turn to southeast, this mouth will be away from the harbor and the effects aroused by the sand will be getting smaller.The route changed into Beicha river will flow into sea from the south of the Gudong sea wall; sediment diffuseness will affect the oil field directly. Averagely, the Gudong bay will be filled up between 3-18cm per year, and it will be strengthened with the sand quantity increase after the 2002. It will improve the sea wall scouring status, increasing the security of the Gudong bank. At the same time, the estuary will push out and creating a large area of land in near future which can make the oil exploits on land instead of in the sea.Some suggestions are obtained in the end of this paper. That is said it is necessary to master the rule of the estuary evolvement based on improving the forecast of flow and sediment, strengthening the observation of estuary channel process and ocean dynamic and research scientifically, First of all, it should make sure that changing the estuary does not affect an influence on the route and fixed number of year of channel. Also, the time of changing the estuary route scientifically must consider both the oil field development and its exploitation in beach area.更多还原