本文選題：渤海東部 + 潮流沉積��； 參考：《中國海洋大學》2014年博士論文

【摘要】：渤海東部海底地貌是一個在成因上相互關聯的完整潮流地貌體系，地貌類型和分布特征受潮流動力格局的控制。本文根據“中國近海海洋綜合調查與評價專項”在渤海區(qū)塊的表層沉積物、礦物分析資料，利用國家自然科學基金項目“遼東淺灘潮流沙脊演化過程及響應機制”在研究區(qū)海域開展的海底地形地貌勘測所獲取的沙脊和溝槽海流同步觀測、水深地形、表層沉積物及測掃聲吶調查資料，研究了沙脊-溝槽-沙席的地貌類型與分布、微地貌特征和不同地貌單元的粒度分布等，采用沙波遷移速率計算和數值模擬等方法探討了沙波的發(fā)育條件等。依據海流平面及垂向觀測資料，研究了沙脊-溝槽的海流分布規(guī)律，探討了研究區(qū)潮流地貌演化趨勢及控制因素，研究結果表明： （1）老鐵山水道東側E-W向長度約49km，西側NE-SW向長度約43km，中央區(qū)深槽長88km，寬度約20km，最大水深86m，表層沉積物主要是粗粒的泥質砂質礫，分選程度極差；遼東淺灘沙脊間距7.0~16.8km，脊槽高差6.8~21.9km，，沉積物以砂為主，分選較好，在沙脊脊部發(fā)育大型、中型沙波；沙脊間溝槽沉積物主要為砂質粉砂、粉砂質砂、粉砂等，分選差；渤中淺灘沙席中央區(qū)面積約670km2，表層沉積物以泥質砂為主，分選較差。老鐵山水道表層沉積物中石榴石、鈦鐵礦穩(wěn)定重礦物的含量小于10%，遼東淺灘穩(wěn)定重礦物含量大于15%；渤中淺灘沙席穩(wěn)定重礦物含量在10~20%之間。 （2）遼東淺灘沙脊區(qū)的沙波主要發(fā)育在底質平均粒徑在1.6~2.9φ、最大底流速52.2~67.0cm/s范圍，水深大致在16~26m的沙脊脊部，以不對稱沙波為主，緩坡位于西南側，陡坡位于東北側，沙波波長在2~23m，波高0.2~1.2m之間，沙波走向基本為WNW-ESE向；沙脊間溝槽底質粒徑3.2~5.3φ，最大底流速33.3~35.0cm/s，不發(fā)育沙波。根據Shinohara沙波遷移速率計算公式計算的沙波遷移速率在3.26×10-6~2.65×10-4cm/s范圍內，最大遷移距離在1.6~7.6cm/d范圍內，沙波形態(tài)特征和凈遷移方向反映出沙脊脊部沉積物凈運移方向與潮流主流向大體一致，為NNE向。 （3）高、低潮時，沙脊區(qū)潮流主流向為NNE-SSW向，流向與沙脊長軸向夾角為9~30°，脊部表層最大流速在103.9~118.8cm/s之間、底層最大流速在52.2~67.0cm/s之間，槽部表層最大流速在108.7~124.3cm/s之間、底層最大流速在33.3~35.0cm/s之間，脊部底流速大于槽部底流速的分界水深約為0.7H層（H為水深值）。沙脊脊部由于流速大，逐漸遭受侵蝕，侵蝕泥沙向NNE凈運移；槽部流速小，除大潮期高低潮時外，潮流流速小于沉積物起動流速，因此沙脊間槽部多數時間處于淤積狀態(tài)，個別時刻略有侵蝕。 （4）老鐵山水道仍然是沙脊和沙席的主要物源區(qū)，在高流速動力條件下，水道海底繼續(xù)遭受侵蝕，水深會緩慢增加，經老鐵山水道向遼東淺灘和渤中淺灘搬運的泥沙趨于減少。遼東淺灘沙脊與沙脊間溝槽潮流流速的差異導致沙脊脊部逐漸侵蝕，槽部趨于淤淺，脊槽高差逐漸減小，脊槽地貌趨于夷平，沙脊沿潮流主流向發(fā)生遷移，沙脊-溝槽地貌進入退化階段。但根據研究區(qū)目前的潮流格局、水深地形、沉積物粒度和沙波遷移速率分析，遼東淺灘脊槽地貌格局在百年尺度內仍會保持穩(wěn)定。
[Abstract]:According to the survey data of surface sediments and minerals in the Bohai Sea area , the authors have studied the geomorphic types and distribution of the sand ridge - channel - sand table , the micro - geomorphic features and the particle size distribution of different geomorphic units .

( 1 ) The east side E - W of Laotieshan waterway is about 49km in length , NE - SW in the west side is about 43km in length , the deep groove of central area is 88km , the width is about 20km , the maximum water depth is 86m , the surface sediments are mainly coarse sand gravel , and the degree of separation is extremely poor ;
The sand ridge spacing of the shallow beach in Liaodong is 7.0 - 16.8km , the height difference of the ridge is 6.8 - 21.9km , the sediments are mainly sand , the separation is better , and large - sized and medium - sized sand waves are developed at the ridge part of the sand ridge ;
The inter - ridge trench sediments are mainly sandy silt , silty sand , silt and the like , with poor sorting ;
The area of the central area of the sand table in Bonzhong shoal is about 670 km2 , and the surface sediments are dominated by muddy sand . The content of the stabilized heavy minerals in the surface sediments of the Laotieshan channel is less than 10 % , and the stable heavy mineral content in the shoal of the Liaodong shoal is more than 15 % ;
The stable heavy mineral content is between 10 and 20 % .

( 2 ) The sand wave in the sand ridge area of the shallow beach in Liaodong area is mainly developed in the range of 1.6 ~ 2.9 蠁 , the maximum bottom flow velocity is 52.2 ~ 67.0 cm / s , the water depth is approximately 16 ~ 26m , the gentle slope is located in the south of the southwest , the steep slope is located in the northeast side , the wave length is between 2 ~ 23m and the wave height is 0.2 ~ 1.2 m , and the wave direction is basically WNW - ESE ;
In the range of 3.26 脳 10 - 6 ~ 2.65 脳 10 - 4 cm / s , the maximum migration distance is within the range of 3.6 脳 10 - 6 ~ 2.65 脳 10 - 4 cm / s . The maximum transfer distance is within the range of 1.6 ~ 7.6 cm / d . The sediment transport direction of sand - wave form is consistent with the trend of the trend of the flow of sediment in the ridge part of the ridge . It is in the direction of the direction of the direction .

( 3 ) When high and low tide , the trend of the tidal current in the sand ridge area is in the direction of NE - SSW , the flow direction and the longitudinal axis of the sand ridge are between 9 and 30 degrees , the maximum flow velocity of the surface layer of the ridge part is between 103.9 and 118.3 cm / s , the maximum flow velocity of the bottom layer is between 53.2 and 67.0 cm / s , and the maximum flow velocity of the bottom layer is between 53.2 and 31.0cm / s , and the maximum flow velocity of the bottom layer is about 0.7H layer ( H is the water depth value ) .
The flow velocity of the trough is small , except for the high tide period . The flow velocity is less than that of sediment start , so most of the time of the trough of the ridge is in the siltation state , and the individual time is slightly eroded .

( 4 ) The Laotieshan water channel is still the main source area of sand ridge and sand table . Under the condition of high flow velocity , the sediment tends to be eroded and the water depth increases slowly .
【學位授予單位】：中國海洋大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：P737.2

【參考文獻】

相關期刊論文 前10條

1 蔣東輝,高抒;渤海海峽潮流底應力與沉積物分布的關系[J];沉積學報;2002年04期

2 吳自銀;曹振軼;王小波;鄭玉龍;;海底沙脊地貌的研究現狀及進展[J];海洋學研究;2006年03期

3 汪亞平,高抒,賈建軍;膠州灣及鄰近海域沉積物分布特征和運移趨勢[J];地理學報;2000年04期

4 李國勝,王海龍,董超;黃河入海泥沙輸運及沉積過程的數值模擬[J];地理學報;2005年05期

5 朱龍海;吳建政;胡日軍;徐永臣;王楠;;近20年遼河三角洲地貌演化[J];地理學報;2009年03期

6 吳濤;康建成;王芳;鄭琰明;;全球海平面變化研究新進展[J];地球科學進展;2006年07期

7 朱玉榮;線狀沙脊形成與維持機制的研究[J];地球科學進展;1998年01期

8 李玉中,陳沈良;洋山港海域現代沉積物運移趨勢[J];地質學報;2003年03期

9 欒錫武;彭學超;王英民;邱燕;;南海北部陸架海底沙波基本特征及屬性[J];地質學報;2010年02期

10 趙娟,范代讀,李從先;蘇北海岸帶潮成輻射砂脊群的形成及其古地理意義[J];古地理學報;2004年01期

相關博士學位論文 前2條

1 朱龍海;遼東淺灘潮流沉積動力地貌學研究[D];中國海洋大學;2010年

2 張立奎;渤海灣海岸帶環(huán)境演變及控制因素研究[D];中國海洋大學;2012年

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