【摘要】：黃河三角洲北部海域6級以上大風頻發(fā)，寒潮大風期間，由于風暴潮與天文大潮疊加造成水位暴漲，同時在大風浪的作用下，海岸侵蝕、碼頭防波堤垮塌等事故極易發(fā)生，造成巨大的經(jīng)濟損失。在極端海況下泥沙運動異�；钴S，驟沖驟淤頻發(fā)，造成石油平臺、管道的破壞及航道、港池的淤積。因此對極端海況下泥沙運動及其動力機制的研究是非常重要的。本文系統(tǒng)地分析了風在風暴潮、波浪、沖淤等方面起到的重要作用，對于寒潮大風期間的災(zāi)害預警和海岸工程的防護具有一定的實踐意義。 本文以中心二號平臺實測風資料為輸入條件，建立了整個渤海海域的風暴潮模型和波浪模型，并結(jié)合大風過程的實測風、潮位、海流、波浪資料分析了大風對于水動力的影響。結(jié)果表明：①黃河三角洲北部海域E向、N向風引起增水，S向、W向風引起減水；當風與流速方向一致時，流速增大，當風與流速方向相反時，流速減��；偏E、NE風存在較長的風區(qū)可以在該海域產(chǎn)生較大的波浪。②在SW風的影響下，研究海域發(fā)生了減水現(xiàn)象，減水幅度均為0.3m左右，在E向風的作用下黃河三角洲北部海域內(nèi)劇烈增水,增水幅度可達0.8m-1m，增水等值線呈南北向分布，且西側(cè)增水值大于東側(cè)；在E風作用下，研究海域落潮流優(yōu)勢明顯；不論在E、NE風作用下，還是在W風、NW風作用下，波浪均呈從東向西逐漸變小的趨勢，淺水區(qū)波浪等值線近似平行于等深線，但是E、NE風導致研究海域波浪較大，有效波高可達2.4m左右。 本文分析了實測懸沙數(shù)據(jù)與波浪、潮流的相關(guān)關(guān)系，同時進行了黃河口附近海域懸沙分布和沖淤的計算，結(jié)果顯示：①研究區(qū)懸沙濃度時間分布主要受波高的控制，懸沙空間分布由潮流和波浪兩個因素控制，波流共同作用下懸沙高值中心與純潮流懸沙高值中心基本對應(yīng)，但懸沙濃度有較大程度的提高。②2013年4月份E風頻發(fā)，實際沖淤受波浪影響較大，其中清水溝入�？诟浇鼪_刷量具有了較大程度的提高，同時黃河三角洲北部海域也有兩方面的變化：一是5m等深線附近出現(xiàn)一個侵蝕中心，月沖刷量為0.02m以上，二是侵蝕中心南側(cè)近岸處出現(xiàn)沖刷。 一個大風過程前后實測沉積物粒度特征顯示，大風使位于1.5m—4m等深線之間南北向分布4個采樣點沉積物變細，這種現(xiàn)象主要由研究區(qū)內(nèi)偏E向風及測線處流場特征造成的：偏E向風導致泥沙以沿岸運動為主，而流速在測線處的降低導致了粉砂粒級沉積物的沉降，，使沉積物變細。
[Abstract]:In the northern waters of the Yellow River Delta, strong winds of Grade 6 or above occur frequently. During the period of cold high winds, the water level rises sharply due to the superposition of storm surges and astronomical tides. At the same time, under the action of the heavy wind and waves, coastal erosion and breakwater collapse at the wharf are very easy to occur. Causing enormous economic losses. Under extreme sea conditions, sediment movement is very active, sudden erosion and sudden siltation occur frequently, which results in the destruction of oil platform, pipeline and channel, as well as the siltation of harbor pool. Therefore, it is very important to study the sediment movement and its dynamic mechanism under extreme sea conditions. This paper systematically analyzes the important role of wind in storm surge, wave, scour and silt, etc., which has certain practical significance for early warning of disasters during cold wave and strong wind and protection of coastal engineering. In this paper, the storm surge model and wave model of the whole Bohai Sea are established on the basis of the measured wind data from the Central platform No. 2, and the effect of strong wind on hydrodynamics is analyzed by combining the measured wind, tide level, current and wave data of the gale process. The results show that: (1) in the northern Yellow River Delta, E, N, S and W directions cause water increase, and the velocity increases when the wind is in the same direction as the velocity of velocity, and decreases when the wind is opposite to the direction of the velocity of velocity; Under the influence of SW wind, the phenomenon of water reduction occurs in the study area, and the range of water reduction is about 0.3 m. Under the action of E-wind, the water increase in the northern waters of the Yellow River Delta can be as high as 0.8m-1m.The water increment isoline is distributed in the north-south direction, and the increase value in the west side is larger than that in the east side. Under the action of E wind, the advantage of the tidal current in the study area is obvious. Under the action of NE wind, W wind and NW wind, the waves tend to decrease gradually from east to west, and the wave isolines in shallow water are approximately parallel to the isobath, but the waves in the studied sea area are larger. The effective wave height is about 2.4 m. In this paper, the correlation between measured suspended sediment data and wave and tidal current is analyzed. At the same time, the suspended sediment distribution and scour and deposition in the waters near the Yellow River estuary are calculated. The results show that: 1 the time distribution of suspended sediment concentration in the study area is mainly controlled by wave height. The spatial distribution of suspended sediment is controlled by two factors: tidal current and wave. Under the action of wave and current, the suspended sediment height center corresponds to the pure tidal current suspended sediment height center, but the suspended sediment concentration increases to a large extent. The actual scour and siltation are influenced by the waves, and the scour amount near the mouth of the clear water ditch has been increased to a great extent, and there are two changes in the northern waters of the Yellow River Delta: one is that there is an erosion center near the 5m isobath. The amount of monthly scour is more than 0.02 m, and the second is erosion near the south side of the erosion center. The grain size characteristics of sediments measured before and after a strong wind process showed that the strong wind thinned the sediments of the four sampling sites located between the 1.5m-4m isobath and the north-south direction. This phenomenon is mainly caused by the characteristics of the flow field along the deviated E-direction wind and the measured line in the study area. The eolian wind causes the sediment to move mainly along the coast, while the decrease of the velocity of velocity in the measured line leads to the sedimentation of silt-sand sediment and the thinning of the sediment.
【學位授予單位】：中國海洋大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：P731.2;TV148

【引證文獻】

相關(guān)博士學位論文 前1條

1 王虎;波浪作用下黃河三角洲海床失穩(wěn)機制與評價方法[D];中國海洋大學;2015年

本文編號：2319552