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辽河三角洲地貌演化(英文) 总被引:1,自引:0,他引:1
This paper mainly analyzes the geomorphological changes of the tidal deposition in the Liaohe Estuary based on the multi-year
bathymetric charts in 1990, 1996, 2002 and 2005 and Landsat TM images in 1987, 1994, 2002 and 2005. Evolution of the tidal
depositional system during the past 20 years in the Liaohe River was studied on the basis of 50 boreholes drilling and 30
km shallow stratigraphic exploration from 2002 to 2005. The main tidal depositional body of the modern Liaohe River delta
is located in the Shuangtaizihe Estuary. The stratum within the depth of 10 m includes tidal bank facies, tidal channel facies
and neritic facies with paleo-delta facies underlying them. The sediments of tidal bank facies are mainly composed of sand
and silt with siltation load and suspended load of about 50% respectively in proportion. The sediment of tidal channel facies
and neritic facies is composed of clayey silt and silty clay which belongs to suspended load. The study area was a small bay
between the old Daliaohe River, the old Dalinghe River and the Raoyanghe River complex delta since the Holocene to 1896. Many
tidal banks formed and expanded rapidly after the Shuangtaizihe River was excavated by labor in 1896. The runoff and sediment
discharge have decreased since the construction of brake at the Shuangtaizihe River in 1958.The Shuangtaizihe Estuary is in
the state of deposition as a whole whose tidal bank is increasing and expanding southward, westward and northward. The maximum
expansion speed is 87 to 683 m/a and the mean depositional rate is 0.189 m/a. Erosion occurred in some part of tidal bank
with average erosional rate of 0.122 m/a. The tidal channel was filled up with sediment at a migration speed of 48–200 m/a.
Geomorphologic changes have happened under the combined influences of runoff, ocean dynamics and human activities. The main
source of sediment changes from river sediment to sediment driven by tidal current and longshore current. 相似文献
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根据莱州湾西南部207个表层沉积物样品的粒度分析结果,对莱州湾西南部沉积物粒度分布特征进行了研究,在此基础上应用系统聚类分析方法并结合物源及水动力条件探讨了其现代沉积环境分区。结果表明,研究区表层沉积物类型以粉砂质砂、砂质粉砂和粉砂为主,分布范围最广的粉砂主要位于淄脉沟以北;沉积物平均粒径由近岸向莱州湾中部逐渐变细,从南向北呈现粗—细—粗的变化趋势;研究区现代沉积环境分为高能粉砂质砂粗粒沉积区、砂质粉砂过渡沉积区以及低能粉砂细粒沉积区,其水动力环境表现为波浪作用逐渐减弱,潮流作用逐渐增强,沉积物物源由近岸河流、岸滩侵蚀来沙为主变为以黄河悬浮—再悬浮物质为主。 相似文献
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双台子河口区悬沙分布和运移特征 总被引:2,自引:0,他引:2
利用海流与悬沙含量实测资料相结合的方法,对双台子河口悬沙运动进行分析。结果表明本区含沙量与波浪、潮流等水动力关系密切,双台子河悬浮泥沙中的细颗粒物质经落潮流搬运至较深水域的潮道和浅海进行沉积,泥沙入海沉积后,接受海洋水动力作用的改造,部分细颗粒物质在水动力作用下会再次起动、运移。悬浮泥沙中的细颗粒物质主要有两个来源:一是波浪、潮流输运而来的大辽河、大凌河等河流物质,二是波浪、潮流对周边海域沉积物质的搬运。1990--2002年研究区整体处于淤积状态,淤积物主要为粒径在2~4Φ的粗颗粒物质,这些物质主要来自于波浪、潮流对河口潮滩的侵蚀、冲刷。 相似文献
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西沙群岛岛屿类型划分及其特征的研究 总被引:6,自引:0,他引:6
西沙群岛是我国重要的生物礁区之一,岛屿星罗棋布,类型繁多.研究这些岛屿的类型及其特征,对判断礁区环境演变、礁体组合成生与发展有着重要的思义;对研究古生物礁的比较沉积学亦有现实意义.一、西沙群岛的自然地理概况 相似文献
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利用旁扫声呐、浅地层剖面、测深以及钻探等资料分析了海南岛乐东陆架区海底沙波的形态特征、底质及地层结构;分常态和台风作用两种环境条件。计算了沙波的移动速率.并与海南岛东方陆架区沙波特征进行了对比分析.研究表明:乐东陆架沙波以大型沙丘和小型沙波为主。其剖面都极不对称.沙丘多为新月形,波长多为50~100m,波高多为1~3m,对称系数在6~12之间;小型沙歧脊残多置直线型,波高多在0.1~0.5m之间.研究区沙波活动性较强,常态下迁移速率与东方沙波区西区相同,每年0.06~2m;在台风影响下,沙丘表面活动砂层的移动性增强,在活动砂体迁移的部位则可能出现冲蚀凹坑或沟槽;中小型沙波移动速率骤增,最大可达7~11m/h。 相似文献
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利用粒子追踪、中子活化示踪砂技术以及赵冲久和Yalin等相关公式对黄骅港抛泥区泥沙运移规律进行了研究,并在此基础上分析了抛泥区对黄骅港航道淤积的影响。结果表明,在正常天气下,抛泥区的泥沙运移主要受潮流控制;在大风条件下,泥沙运移则受到波浪、潮流、风生流等多种因素的影响;抛泥区泥沙几乎不会对航道淤积产生直接影响,其对航道淤积的影响是间接和有限的。 相似文献
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