杭州湾淤泥质海岸岸线变化及其动态模拟

通过对杭州湾北岸南竹港-龙泉岸段实测岸滩断面资料的统计分析,进而对淤泥质海岸岸线变化、影响因素及其动态模拟预报进行探讨。结果表明:因长江来沙减少以及侵蚀/淤积波自东向西移动,导致近10a来该岸段岸滩处于侵蚀状态,其中岸线整体后退;因季节性的波侯作用,岸滩具有冬淤夏冲的特征,岸线则表现为冬涨夏退,因局部工程作用影响的岸线则具有冬退夏涨的特征。此外,基于-3m和-8m等深线构建的径向基函数神经网络模型预报岸线的变化是可行的。     

Numerical Modeling of Suspended Sediment Transport in the Gulf of Kachchh Including Kandla Creek, West Coast of India

A depth-averaged numerical model has been developed to study tidal circulation and suspended sediment transport in the Gulf of Kachchh including Kandla creek, west coast of India. The resolution of the model is taken as 750 m × 750 m, which is found to be adequate for the gulf region. However, this resolution could not produce the realistic circulation pattern and suspended sediment concentration in the Kandla creek region. There is a major seaport at Kandla which serves as the sea gate to northwest India. Therefore, a 2-D fine resolution (75 m × 75 m) model for Kandla creek has been developed and coupled with the coarser gulf model to compute the flow features in the creek region. The model dynamics and basic formulation remain the same for both the gulf model and the creek model. The models are barotropic, based on shallow water equations, and neglect horizontal diffusion and wind stress terms in the momentum equations. The models are fully nonlinear and use a semiexplicit finite difference scheme to solve mass, momentum, and advection-diffusion equations in a horizontal plane. The tide in the gulf is represented in the model by the semidiurnal M₂ constituent mainly. In this study, no fresh water discharge conditions have been considered so the results are appropriate for the dry season. Numerical experiments are carried out to study the circulation and suspended sediment concentrations in the gulf and the creek regions. The computed results are validated with the available observations.     

Remote Sensing Analysis of the Suspended Sediment Transport in Lingdingyang

- The data of landsat TM of multi-temporal for Lingdingyang Estuary, Pearl River in China is firstly used with suspended sediment concentration of field measurement to establish a correlative model equation. After the ratio processing of TM data and atmospheric correction, the images of suspended sediment concentration of different temporals are exported from the image processing systems AREIS II and III. These images express the characteristics of suspended sediment distribution, the mode of sediment transport and the extent of dispersion under the actions of tidal current and wind condition of different seasons.     

粉砂淤泥质海岸人造沙滩效果——以上海金山城市沙滩为例

上海市金山区位于杭州湾北岸,发育典型的粉砂淤泥质海岸,潮滩低平、颗粒极细,下陷0.1~0.2 m,且风暴潮期间海水泥沙含量极高,泥层易滑塌。2005年,在金山潮滩构筑3.3 km封闭式围堰围海成湖1.72 km2,近岸抛沙15.6万m3并设防泥网建成长度1.4 km的人造沙滩进行跳相养滩,后经多次补沙和围堰加固,将“黄水黑滩”变为“碧海金沙”,成为金山城市沙滩。该人造沙滩是中国首个泥岸养滩成功案例,后有天津东疆浴场、潍坊央子人造沙滩、南通启东碧海银滩等10余个人造沙滩建成。金山城市沙滩封闭式围堰消浪护沙、稳定沙滩,结合“沉泥碧水”技术维持海水清洁且防止新滩泥化;固定式防泥网较为坚固,保证游人安全。其围海成湖、沉泥碧水、抛沙建滩及泥沙界网等工程技术为中国粉砂淤泥质海岸人造沙滩建设提供了实践经验。     

基于ArcGIS的倾倒区水深地形冲淤变化分析

东碇临时海洋倾倒区是当前福建省内使用频率最高、倾倒量最大的海洋倾倒区,自2010年重新投入使用以来,该倾倒区共接纳了约1.5×107 m3的疏浚物,为研究其海底地形冲淤变化情况,利用ArcGIS的空间分析模块、3D分析模块、地统计分析模块等对东碇临时海洋倾倒区进行冲淤变化分析,文中介绍了冲淤分析的基本流程并对分析结果进行讨论,说明疏浚物倾倒对水深地形的影响程度。     

Numerical Modeling of Suspended Sediment Transport in the Gulf of Kachchh Including Kandla Creek,West Coast of India

A depth-averaged numerical model has been developed to study tidal circulation and suspended sediment transport in the Gulf of Kachchh including Kandla creek, west coast of India. The resolution of the model is taken as 750 m × 750 m, which is found to be adequate for the gulf region. However, this resolution could not produce the realistic circulation pattern and suspended sediment concentration in the Kandla creek region. There is a major seaport at Kandla which serves as the sea gate to northwest India. Therefore, a 2-D fine resolution (75 m × 75 m) model for Kandla creek has been developed and coupled with the coarser gulf model to compute the flow features in the creek region. The model dynamics and basic formulation remain the same for both the gulf model and the creek model. The models are barotropic, based on shallow water equations, and neglect horizontal diffusion and wind stress terms in the momentum equations. The models are fully nonlinear and use a semiexplicit finite difference scheme to solve mass, momentum, and advection-diffusion equations in a horizontal plane. The tide in the gulf is represented in the model by the semidiurnal M₂ constituent mainly. In this study, no fresh water discharge conditions have been considered so the results are appropriate for the dry season. Numerical experiments are carried out to study the circulation and suspended sediment concentrations in the gulf and the creek regions. The computed results are validated with the available observations.     

庵东浅滩沉积分带和沉积速率

杭州湾南岸的庵东浅滩具有地貌特征、沉积类型和沉积构造各异的三个沉积相带。垂向沉积带为潮滩沉积体的盖层,以泥滩、粘土质粉砂和薄砂泥交互层为特征;改造带位于中低潮位线附近,以粉砂滩、潮沟系统、粉砂沉积和沙波层理为特征;横向沉积带为潮滩堆积体的基础,以滩坡、粉砂及细砂质粉砂沉积、冲刷-充填构造为特征。据潮汐韵律层的统计,庵东浅滩沉积速率的短周期分量,常态条件下为每半日潮周期0.1～2.0cm,异常条件下可达每半日潮周期4～64cm。沉积速率的长周期分量,据地形对比和~(210)Pb推算,垂向沉积带为2～4.5cm/a;改造带中的粉砂滩为2.1～4.5cm/a,潮沟影响范围内为1～10~1cm/a量级;横向沉积带则以高于50cm/a的高沉积速率和变幅为主。近10年来,该浅滩的年淤积量为6×10~7t/a,其中85％集中于横向沉积带。     

不同悬沙组分对潮流的响应关系研究

通过建立一维水深平均悬沙模型,对典型潮流控制的海湾内不同悬沙组分对潮流的响应关系进行了研究。模型以泥沙的水平输运、再悬浮和沉降为主要物理过程,以M2,S2分潮及余流为主要动力因素,反演了湄洲湾支水道内粉砂、淤泥组分含量的时间序列,采用2007-08潮位、潮流、悬沙、底质同步观测资料进行分析和验证。通过三角傅里叶分析,将悬沙的时间序列分解为12个主要的谐波分量,模型分解得到的主要傅里叶分量具有M2分潮两倍的角速度与1/4日潮周期,该分量粉砂组分振幅6.1 mg/L,淤泥组分振幅1.5 mg/L;次主要傅里叶分量具有M2分潮的角速度,振幅受水平输沙、余流、M2分潮流共同影响,粉砂组分振幅4.9 mg/L,淤泥组分振幅1.2 mg/L。由于粉砂组分单位起动能力强、沉降速度高,且淤泥组分由于粘结力等因素起动条件较高,粉砂组分振幅高于淤泥组分。测站位置余流与涨潮流方向一致,余流致使涨潮过程中粉砂组分含量所占百分比上升,而落潮过程下降,淤泥组分则相反。     

丁坝间潮滩地貌变化的经验正交函数分析

经验正交函 数(EOF)是用来处理原始数据、进行多元统计分析的一种方法。本文将原始距平矩阵分解为空间特征函数和相应的时间特征函数,并用前3个经验正交函数,即表示潮滩总体冲淤变化的第一特征函数,表示季节性冲淤变化的第二特征函数和表示偶然因素扰动引起冲淤变化的第三特征函数的线性组合来反映潮滩的变化,分析浙江瑞安淤泥质潮滩在建立丁坝后的演变规律。初步探讨了动力过程和地貌之间的关系,分析了淤泥质潮滩在丁坝工程影响下的时空变化特征与动力过程的关系;并对第二特征函数对应的动力过程进行详细阐述,结果显示波浪作用是影响浙江瑞安淤泥质潮滩季节性变化的主要因素。     

东海岛东北部砂质岸滩年度冲淤变化及沉积物运移分析

东海岛是全国第五大岛,其东部长达28km的海滩是"中国第一长滩"。近年来因海平面上升和人类开发,该海滩局部出现较为严重的海岸侵蚀。基于高精度GPS监测结果及表层沉积物粒度测试结果,使用GSTA趋势分析模型,研究了东海岛东北部砂质岸滩的季节性冲淤变化及沉积物运移趋势,探讨了海岸侵蚀机制。结果表明,研究区岸滩沉积物的运移主要受潮流的控制,以沿岸向北运移为主。研究区南部岸滩紧邻低滩灯塔形成的波影区,沉积物供应较少,岸滩以侵蚀为主;研究区北部沿岸流搬运的沉积物能从南侧得到补给,加之向岸运移的沉积物,岸滩多处于淤积状态。     

Atmospheric Correction of SeaWiFS Data for the Retrieval of Suspended Sediment in East China Coastal Waters

The data of SeaWiFS (Sea-Viewing Wide Field-of-View Sensor), installed on SeaStar, has been used to generate SSC (suspended sediment concentration) of complex and turbid coastal waters in China. In view of the problems of the SeaDAS (SeaWiFS Data Analysis System) algorithm applied to China coastal waters, a new atmospheric correction algorithm is discussed, developed, and used for the SSC of East China coastal waters. The advantages of the new algorithm are described through the comparison of the restdts from different algorithms.     

上海洋山深水港区海域悬沙分布特征及运动规律分析

以1998年以来定点实测含沙量资料为基础,结合1996-2007年不同时刻卫星遥感影像资料对洋山港附近海域悬沙分布特征及运动规律进行分析,结果表明:洋山港海域含沙量存在着明显的季节变化;潮差越大,水体紊动越强,水体含沙量越高;洋山港水域含沙量明显高于其周围的水域,特别是在大小洋山岛链之间,呈现由北向南、由东向西逐渐增大的趋势;"峡岛效应"也是引起高含沙量一个重要原因;长江入海泥沙直接扩散对洋山港水体含沙量的影响较小,研究区域水体含沙量的大小主要取决于波况及潮流对当地浅滩的掀扬及输送.     

基于无人机的用海项目施工期悬浮泥沙监测

为实现对用海项目施工期悬浮泥沙扩散的实时跟踪监测,尝试采用无人机携带可见光、多光谱传感器对古雷围填海项目的围堰区进行遥感探测。利用Pix4d软件对无人机携带的可见光及多光谱照片进行处理,结果表明,可见光及多光谱影像对水体中的悬浮泥沙分布均具有一定的识别能力。通过研究分析多光谱影像的光谱特征发现,近红外波段对悬浮泥沙含量的升高较为敏感,运用波段比值公式计算结果显示,围堰内含沙水体经溢流口排入海域后浓度明显降低,并可向南继续扩散约300 m。该方法可克服遥感卫星影像时空分辨率低的特点,为用海项目资源环境影响跟踪监测提供新的技术手段。     

泉州湾泥沙运移特征的初步研究

泉州湾属于潮流、径流和波浪综合作用下的山地海湾,根据两次(1994年6月和2001年12月)水文泥沙实测资料,分析泉州湾悬浮泥沙和沉积物分布特征,研究其沉积物来源,并探讨北水道的沉积速率。悬浮泥沙含量自河口(湾顶)-湾口-外海逐渐降低。高值区出现在水道和河口,冬季高于夏季,大、中潮高于小潮。泉州湾沉积物分布与水动力强弱环境呈很好的对应关系。晋江携带入海的泥沙是研究区的主要物源：海岸侵蚀来沙与湾外来沙也提供了部分物源。南、北水道分别属于落潮槽与涨潮槽两种不同性质的水道。北水道沉积物较细,以沉积作用为主,其入口处淤积程度较轻,而在上游淤积程度相对较重;南水道流速较大,沉积物较粗,是泥沙输运主要通道,地形变化不明显。     

波致土体液化下水体含沙量垂向分布试验研究

本文利用波浪水槽试验,对底床粉质土液化状态下水体垂向含沙量分布特征进行了研究。试验结果表明,波浪导致粉质土液化情况下,水体含沙量在近底边界层出现激增,含沙量垂向分布形态呈现出近于L型的特征。     

Investigation on the Deposition in an Excavated Trough at the East Shore of Jiaozhou Bay, China

- Based on field investigations, this paper analyzes three types of harbour basinns and navigation channel excavated on seabed in Jiaozhou Bay, get a general rule of deposition for excavated trough, it found that pollution is one of crucial factors resulting in the deposition of the excavated trough in the east shore of Jiaozhou Bay. With these results, it predicted the annual deposition thickness for the excavated trough and disclosed the fact that it can't be deposited deadly during one storm. At the same time, with two-dimensional numerical model, it studied the effects of the excavated trough and the reclamation near shore on tidal cureent and said that the excavated trough can decrease the current velocity passing through the trough about 10- 15%, but only limited inside and near the trough and there are no effect on other regions; reclamation can cut off the pollution sources and no obvious effect on the currents of the Jiaozhou Bay. Connecting the deep trough and Cangkou tidal channel with a new     

茂名海域水体表层悬浮泥沙浓度时空分布特征的遥感分析

利用Gorden关系式,从茂名海域的多时相卫星影像定量反演了表层悬浮泥沙浓度的时空分布特征。经近期该海域实测悬沙资料验证表明,茂名沿海水体表层悬浮泥沙浓度偏低,一般低于200 mg/L;表层悬浮泥沙浓度在空间尺度上由岸向海呈带状分布,并逐渐降低,其中-1 m以浅区悬沙浓度最高,一般可超过100 mg/L,-10 m以深区浓度最低,一般低于20 mg/L。此外,沿海水体表层悬沙浓度往往在冬季高于夏季,大风天气高于平常天气。     

Sediment dynamic processes of the Yuehu inlet system, Shandong Peninsula, China

In order to investigate the sediment dynamic behavior of the Yuehu, a small inlet system characterized by abundant sediment supply and rapid sediment infilling, measurements and sampling were undertaken to obtain data sets of tidal water levels, current velocities, suspended sediment concentrations, grain size parameters, deposition rates and organic carbon contents. Sediment budget and the time–velocity asymmetry patterns of the inlet system were analyzed. The results show that the deposition rates are relatively high within the tidal basin. The total sediment flux cannot be balanced by the input from the open sea, the aerosol and biological production; rather, the material from land (which has been intensified by agricultural activities over the past several decades) represents a major component for the balance. Thus, the denudation rate must be reduced to protect the Yuehu as a natural reserve. Furthermore, it is found from the present study that the Yuehu inlet system exhibits all of the four time–velocity asymmetry patterns with varied frequencies of occurrence, compared with the two asymmetry patterns identified for larger inlet systems; such phenomena are partly due to the adjustment of entrance channel geometry. This behavior may be representative of the small tidal inlets at their late stage of morphological evolution and, therefore, may be utilized to prolong the lifespan of small inlet systems.     

江苏如东西太阳沙及烂沙洋海域潮流泥沙数值模拟

基于不规则三角形网格有限差分法并考虑波浪及其破碎作用,建立了平面二维潮流场和泥沙场数学模型.该模型对有望建设成深水码头和深水航道的江苏如东西太阳沙和烂沙洋海域的潮流场和泥沙场进行了细化数值模拟.数值模拟结果表明：（1）本海区潮流基本上是顺深槽流动的往复流,潮流流速大,烂沙洋北水道和西太阳沙附近大潮涨落潮最大流速分别在2 m/s和1 m/s以上;（2）本海区的潮平均水体含沙量在0.5 kg/m^3以下,落潮含沙量大于涨潮含沙量;（3）小浪对水体含沙量影响很小,大浪作用下水体含沙量明显增加.     

伶仃河口湾铜鼓水域水沙净输运分析

根据对珠江伶仃河口湾铜鼓水域丰水期９个测站大、中、小潮三次同步水文泥沙资料及５７个底质样品的分析结果,本文讨论了此水域的水沙净输运趋势。结果表明,铜鼓水域表层余流向海,浅滩测站中底层余流指向河口方向,欧拉余流主要由径流构成。沟槽悬沙输运以净平流作用为主,浅滩区则以向上游的潮抽吸输运为主。沉积物净输运趋势显示铜鼓浅滩是海陆双向底质输运的汇聚地带