黃河調水調沙影響下河口入海泥沙擴散及地貌效應
發(fā)布時間:2018-02-21 05:52
本文關鍵詞: 黃河調水調沙工程 入海泥沙擴散 粒度變化 地貌效應 出處:《中國海洋大學》2014年碩士論文 論文類型:學位論文
【摘要】:據(jù)2013年7月黃河調水調沙期間三船同步四斷面(A、B、C、D)25h水文泥沙連續(xù)觀測的資料,分析了四斷面及各斷面所含站位點的流速、含沙量、溫度及鹽度的分布特征,計算了各連續(xù)站表、中、底三個層位的凈泥沙單寬通量,以此來討論調水調沙期間河口入海泥沙擴散和沉積的范圍,,并結合2010年黃河調水調沙期間(7月)和黃河調水調沙前(5月)、調水調沙后(9月)黃河口底質沉積物樣品的實測數(shù)據(jù),提取并分析調水調沙實施前(1996-2002年)和實施后(2002-2008年)的衛(wèi)星遙感數(shù)據(jù)資料,評價黃河調水調沙工程計劃對黃河泥沙及河口地貌效應的作用,得到的主要結論包括: 1)調水調沙期間,高溫低鹽的黃河沖淡水離岸擴散,擴散范圍較大;入海泥沙在向海擴散過程中迅速沉積在近岸的河口口門附近,距岸約11km,擴散的范圍有限,水沙擴散范圍不一致。調水調沙期間各站位溫鹽躍層明顯,在淺水區(qū)域水體垂向混合強烈,分布均勻,在深水區(qū)域懸浮泥沙主要集中在躍層以下的水體中傳輸。 2)黃河調水調沙期間各站連續(xù)25h的凈泥沙單寬通量分布特征顯示,黃河口沿岸懸浮泥沙主要向東及偏東南方向擴散。受徑流影響,河口口門泥沙通量最大可達85×103g/m/s,但在距離河口10km以外區(qū)域通量銳減,清水溝廢棄河口區(qū)通量位于其次,其他地區(qū)通量普遍較低。 3)2010年調水調沙之前,河口附近淤積的泥沙粒徑較粗(以砂和粉砂為主要成分)、分選較好;調水調沙期間入海泥沙主要以粗顆粒物質為主,沉積速率大;調水調沙結束以后,河口地區(qū)表層沉積物的粒徑變細,黏土含量增加,分選變差,說明調水調沙后期入海泥沙粒徑較細,覆蓋在之前沉積的粗顆粒沉積物之上;一段時間后經(jīng)過冬季風暴的侵蝕作用,上覆的細顆粒泥沙通過再懸浮被搬運,之前沉積的粗顆粒泥沙暴露在海底,因不易被搬運而保留。經(jīng)過調水調沙工程逐年進行,河口處粗顆粒泥沙淤積量增多,對河口造陸的貢獻較大。 4)調水調沙實施以前(1996-2002年),河口岸線平均最大淤進速率約為1.7km/a,同時廢棄河口河嘴岸線最大平均每年蝕退0.4km,孤東海域在這一期間岸線以蝕退為主,每年約蝕退0.277km,南部萊州灣的西北則呈現(xiàn)略淤積的特點。調水調沙實施后,河口岸線大幅淤進,最大速率約為0.777km/a,該速率雖小于調水調沙實施之前的平均速率,但由于河口明顯加寬,總淤進面積遠大于1996年至2002年期間河口的淤進面積。河口三角洲蝕積狀態(tài)發(fā)生顯著變化,1996-2002年期間,河口最大淤積厚度量約為4m,且現(xiàn)行水下三角洲葉瓣為凈侵蝕,侵蝕量達0.39Gt(109t),在2002年以后淤積最大厚度可達6m,現(xiàn)行水下三角洲葉瓣為凈淤積,淤積約量為0.28Gt。表明調水調沙實施以后,河口入海泥沙由于擴散范圍有限而沉積在河口附近,使河口岸線向海淤進速率顯著增加而水下三角洲部分由凈侵蝕轉換為凈淤積,增加了黃河入海泥沙的造陸速率。
[Abstract]:According to the data of the continuous observation of the water and sediment of the four sections ( A , B , C , D ) of the Yellow River during the Yellow River Diversion Project in July 2013 , the distribution characteristics of the flow rate , the sediment content , the temperature and the salinity of the stations included in the four sections and each section are analyzed . 1 ) During the water - adjusting and sand - adjusting period , the high - temperature and low - salt Yellow River is diffused and diffused offshore , and the diffusion range is relatively large ; the sediment in the sea is rapidly deposited near the estuary of the nearshore in the process of centripetal diffusion , the range of the diffusion is limited , and the diffusion range of the water sand is not consistent . During the water - adjusting and sand - adjusting period , the temperature - salt jump layer of each station is obvious , the vertical mixing of the water body in the shallow water area is strong , the distribution is uniform , and the suspended sediment in the deep water area is mainly concentrated in the water body below the jump layer . 2 ) The net sediment single - width flux distribution characteristics of continuous 25h in the Yellow River diversion sediment show that the suspended sediment along the Yellow River Estuary is mainly spread in the east and southeast directions . The sediment flux of the estuary is up to 85 脳 103 g / m / s , but the flux of the river mouth is reduced . The flux of the abandoned river mouth area of the clear water ditch is the second , and the flux of other areas is generally lower . 3 ) Before the water diversion and sediment adjustment in 2010 , the sediment grain size in the vicinity of the river mouth is coarse ( mainly composed of sand and silt ) , the separation is good ; the sediment in the surface layer of the river mouth is mainly dominated by coarse granular material and the sedimentation rate is large during the water - adjusting and sand - adjusting period ; 4 ) Before the implementation of water regulation and sand regulation ( 1996 - 2002 ) , the average maximum deposition rate of the river mouth is about 1.7 km / a . At the same time , the maximum average erosion rate of the river mouth is about 0.7km / a , and the maximum velocity is 0.39Gt ( 109t ) . The maximum velocity is 0.39Gt ( 109t ) . The maximum velocity is 0.39Gt ( 109t ) .
【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】:P737.1
【參考文獻】
相關期刊論文 前7條
1 彭俊;陳沈良;;近60年黃河水沙變化過程及其對三角洲的影響[J];地理學報;2009年11期
2 ;STABILIZATION OF THE YELLOW RIVER CHANNEL AND DEVELOPMENT OF THE DELTA[J];International Journal of Sediment Research;1998年02期
3 黃世光;;黃河刁口流路泥沙沖淤及其演變特征[J];海岸工程;1991年03期
4 李廣雪;黃河入海泥沙擴散與河海相互作用[J];海洋地質與第四紀地質;1999年03期
5 李平;豐愛平;陳義中;陳沈良;;2005年黃河調水調沙期間入海泥沙擴散研究[J];海洋湖沼通報;2010年04期
6 趙業(yè)安;潘賢娣;申冠卿;;80年代黃河水沙基本情況及特點[J];人民黃河;1992年04期
7 張建民;單紅仙;賈永剛;劉紅軍;許國輝;;波浪和潮波作用下黃河口快速沉積海床土非均勻固結試驗研究[J];巖土力學;2007年07期
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