黄河入海泥沙输运及沉积过程的数值模拟

以利津站代表的黄河入海径流和泥沙数据驱动ECOMSED模型,对黄河入海泥沙悬移输运过程的逐月时空变化、输送通量以及海底沉积效应进行了数值模拟实验。分析结果表明,在忽略再悬浮作用条件下,黄河入海泥沙的输运扩散过程具有明显的季节变化规律,且这种变化具有年际相似性。黄河泥沙入渤海后总体朝向辽东湾西侧海岸扩散,而主要沉降区域是黄河口附近,且随着距离的增大,沉积通量迅速降低。模拟沉积速率一般在0.5~0.1 mm/年左右,与实际调查结果非常接近。海底地形等高线向渤海海盆西部、渤海湾南部,以及渤海海峡方向突出,也反映了泥沙通量的输送方向。从黄河入海泥沙悬移扩散过程的季节变化特征及其海底沉积效应来看,渤海海域泥沙悬移输运过程受潮汐动力、余流和和底层流场等因子的制约。除了黄河河口地区以外,各月悬浮泥沙高浓度区基本一致,集中分布在潮流能量最强的海域,潮流水平动能的大小与悬沙浓度大小分布基本一致。泥沙悬移输运方向与模拟获得的渤海三维风驱-潮致Lagrange余流的方向具有明显的相关关系,泥沙扩散的方向和强度明显受余流方向和强度的控制。     

渤海与环渤海地区年降水量的统计分析

本文以渤海海域及环渤海地区分水岭内为研究区域,利用环渤海地区分水岭内92个气象站点自1971年至2000年30年的降水量资料,基于ARC/INFO地理信息系统支持下的泰森多边形法,对研究区域内的平均年降水量进行了统计分析。结论如下:环渤海地区分水岭以内区域的平均年降水量占整个环渤海地区2000年降水量的63.88%;渤海海域海水直接利用量占该海域平均年降水量的8.82%,其中辽东湾的海水利用量占该湾平均年降水量的3.09%,渤海湾为15.86%,莱州湾为17.38%;辽东湾2002年的海冰资源量占该湾平均年降水量的6.08%。在渤海海域水量平衡的关系研究中,本研究是初步的,基础的。划出分水岭内的研究区域进行平均年降水量的统计较对整个环渤海地区进行统计更具精确性。     

渤海氮污染的来源结构与污染压力空间分布

近30年渤海环境发生了巨大变化,陆源污染输入是导致渤海环境恶化的主要原因。为研究陆源污染压力强度与海域污染的空间关系,采用层级嵌套的水污染输出分区方法,将环渤海地区划分为23个陆海统筹管理分区,并基于土地利用数据、社会经济统计数据和污染普查等资料,估算出环渤海地区五类社会经济活动的总氮排放量,进而分析各分区单元的陆源污染压力。研究结果表明：① 渤海周边陆域总氮排放量约85万t,农业农村面源污染是氮污染的主要来源,占总排放量的57.4%,工业污染贡献有限,渤海湾沿岸城镇居民生活排放突出;② 23个陆海统筹管理分区之间的污染压力差异巨大,辽东湾、渤海湾和莱州湾周边的分区陆源污染压力大,其它分区的压力相对较低,各分区内陆域污染压力与对应海域污染状况在空间上高度一致;③ 各分区之间污染的来源构成差异显著,渤海湾氮污染的主要来源是居民生活排放,辽东湾工业污染相对突出,莱州湾农业面源污染占比大;④ 渤海周边陆源污染排海压力短期内难以缓解。     

白令海峡及其邻近海域潮汐潮能数值模拟

基于非结构三角形网格的FVCOM(Finite-Volume Coastal Ocean Model)海洋数值模式,对白令海峡及其邻近海域的潮汐、潮能进行数值模拟研究。模拟结果同验潮站和实测海流资料符合良好,较好地反映了白令海峡及其邻近海域的潮汐、潮流分布特征和运动状况。根据计算结果绘制了主要分潮的同潮图和潮流椭圆图,对该海域潮汐潮流特征进行了系统分析。结果表明,白令海陆架区、白令海峡和楚科奇海主要以M2分潮为主,而在诺顿湾海域以K1分潮为主,M2分潮潮流在白令海陆架东南部及阿纳德尔湾较强,K1分潮潮流在诺顿湾潮流达到最大值。在此基础上,对其潮汐能的传播与耗散进行分析,结果发现研究海域潮能通量较小,主要分潮在研究海域潮能耗散总量约为751 MW,M2潮能耗散占该总量的52%,K1潮能耗散占38%,潮能进入白令海陆架后,M2分潮主要在圣劳伦斯岛以南陆架区耗散,K1分潮主要在诺顿湾海区耗散。     

洋山港海域潮动力特征及其对工程的响应

距上海陆域外约32 km的洋山港是以小洋山岛链为基础建造的中国首个离岸式深水港口, 其港区陆域是通过封堵北岛链三个主要汊道并抛填成陆而成。大规模的封堵陆连工程改变了该海域的地形边界条件, 海域潮动力特征也随之响应。通过对洋山港海域堵汊陆连工程前后潮位及潮流实测资料的分析研究, 发现洋山港海域的潮动力特征主要表现在:海域潮波倍潮及复合潮增幅随工程的进行而增大, 潮动力表现出明显的非线性特征;海域中部发生壅水;海域潮波向驻波性质变异并于憩流时段引发环状流场。     

埃默里冰架前缘水的特性和海流结构

本文利用中国第19次南极科学考察普里兹湾内埃默里冰架前缘水域观测的LADCP、 CTD资料,研究并分析了普里兹湾内埃默里冰架前缘水域水的温、盐特性和海流结构。资料显示,在冰架前缘的水域中存在着四种典型的夏季水团;流速分布显示出东进西出的特征。此外在普里兹湾内的上层和中层海洋中还存在着逆时针和顺时针方向的涡旋:逆时针涡旋西侧是普里兹湾向冰架入流的位置所在;入流的源地是普里兹湾东侧的沿岸西向流。这些特征涉及到夏季普里兹湾内的环流形式、冰架底部的消融速率和冰架水的生成规模以及冰架区域与冰架外普里兹湾内的水交换形式。     

在沿海地区培育新增长极的构想--胶、辽携手带动环渤海,南、北并进拓展长三角

通过对区域自然地理和社会经济条件的综合分析,论证中国北部和中部沿海新增长极的合理选址所在(分别是渤海的入口处、长江口的崇明岛、位于杭州湾东侧的宁波-舟山),并就如何培育这些新增长极提出了初步的设想,包括:建设“渤海门户组合港”、莱州湾的围海成湖、封堵长江口北支、在崇明岛建设“江北上海”、把整个杭州湾全部围垦成陆。     

民勤“2010.4.24”黑风天气过程的稳定度分析

 2010年4月24日民勤出现黑风天气,给当地经济和社会造成严重影响。利用民勤黑风发生前后2010年4月24日08时~25日08时的探空观测资料,对大气不稳定能量、热力参数“V—3θ”和动力参数“相对风暴水平螺旋度”进行了计算分析。结果表明：黑风发生时,民勤近地面存在正不稳定能量,促使黑风在近地面层爆发性发展,使沙尘粒子在正不稳定能量区聚积,形成黑风墙。民勤黑风爆发前和爆发时大气温湿结构呈现出上湿下干的分布特征,低层湿度较小不利于降水产生,为沙尘扬起提供了较好的垂直方向的环境场条件;黑风爆发前大气层结500 hPa以下风场的垂直分布形成顺时针滚流,为对流性不稳定层结,气层有利于黑风生成和发展;黑风过境后,风场的垂直分布顺时针滚流下降至700 hPa以下,说明大气层结的对流不稳定层结变薄、减弱,700～500 hPa存在逆时针滚流,抑制上升运动,预示黑风将减弱。黑风爆发期间在河西走廊中部存在一个相对风暴水平螺旋度负值中心,中心值达到-870 m2 /s2,远小于强沙尘暴发生的临界值-600 m2 /s2,沙尘暴的强度与相对风暴水平螺旋度负值中心存在很好的对应关系。当民勤测站的相对风暴水平螺旋度＜0,其上游存在≤-600 m2 /s2的最小中心时,民勤测站将出现强沙尘暴;当民勤测站的螺旋度＜0,其上游存在正值中心时,下游存在负值中心时,民勤测站的沙尘暴结束,能见度好转。     

南极普里兹湾附近海域表层海流特征分析

利用第29次南极科考期间在普里兹湾海区释放的8个Argos漂流浮标所获的总计662 d的数据,对普里兹湾及其邻近海域的表层海流特征进行了分析,并和以前的研究结果进行对比,结果表明:普里兹湾西部和北部表层海流基本呈现向西的流动,说明此地区的表层海流以沿南极大陆的逆时针沿岸流为主。普里兹湾东部海流呈现先向南再向西或先向南再向北的流动,普里兹湾西北部海流呈现向南的流动。8个浮标平均流速在0.02—0.20 m·s~(-1)之间,最大流速为1.57 m·s~(-1),流速1.0 m·s~(-1)的大流速区主要集中在普里兹湾、克洛斯角外侧、达恩利角外侧海域,流速1.5 m·s~(-1)的大流速区只出现在普里兹湾、克洛斯角外侧两处海域。     

北极西北航道风能资源调查分析

针对北极西北航道及其战略支点建设既面临生态环境脆弱现状又对能源存在迫切需求的情况,提出评估、利用海上风能资源的建议。基于欧洲中期天气预报中心的风场资料,综合分析风功率密度,资源的可利用率、富集程度、稳定性以及资源技术开发量等要素,对西北航道的风能气候特征展开系统性研究。结果表明:该海域蕴藏着较为丰富且利于航道建设的风能资源,其中风能开发的优势区域为戴维斯海峡以东海区、阿蒙森湾海区以及帕里群岛至麦克林托克海峡的狭长海域(例如维多利亚海峡),而这几个海区也是西北航道通航的关键区域,上述区域在风功率密度的大小、有效风速频率、能级频率、资源储量以及变异系数等方面具有较为明显的优势,而且在长期变化中相关要素没有出现显著的衰退信号。     

A model, study on seasonal spatial-temporal variability of the Lagrangian Residual Circulations in the Bohai Sea

1 IntroductionThe BohaiSea is a sem i-closed shallow sea w ith a m ean depth ofaround 20 m ,com posed oftheLiaodong Bay,the BohaiBay,the Laizhou Bay and the BohaiBasin,and connected to the N orthY ellow Sea through a latitudinal strait. The tidal dynam ic…     

A model study on seasonal spatial-temporal variability of the Lagrangian Residual Circulations in the Bohai Sea

The spatial distribution and seasonal variation of the tide-induced Lagrangian Residual Circulations (LRC hereafter), wind-driven LRC, and the coupling dynamic characteristics were simulated using ECOM, given the Hellerman and Rosenstein global monthly-mean wind stresses. The results showed that the tide-induced LRC of the harmonic constituent m2 bears an identical pattern in four seasons in the Bohai Sea: the surface one is weak with random directions; however, there exist a southeast current from the Bohai Strait to the Laizhou bay, and a weakly anticlockwise gyre in the south of the Bohai Strait for the bottom layer LRC. The magnitude of bottom layer tide-induced LRC is larger than the surface one, and moreover, it contributes significantly to the whole LRC in the Bohai Sea. Unlike the identical structure of the tide-induced LRC, the wind driven LRC varies seasonally under the prevailing monsoon. It forms a distinct gyre under the summer and winter monsoons in July and January respectively, but it seems weak and non-directional in April and September.     

渤海风驱-潮致Lagrange余流的数值模拟与季相时空变异

The spatial distribution and seasonal variation of the tide-induced Lagrangian Residual Circulations (LRC hereafter), wind-driven LRC, and the coupling dynamic characteristics were simulated using ECOM, given the Hellerman and Rosenstein global monthly-mean wind stresses. The results showed that the tide-induced LRC of the harmonic constituent M2 bears an identical pattern in four seasons in the Bohai Sea: the surface one is weak with random directions; however, there exist a southeast current from the Bohai Strait to the Laizhou bay, and a weakly anticlockwise gyre in the south of the Bohai Strait for the bottom layer LRC. The magnitude of bottom layer tide-induced LRC is larger than the surface one, and moreover, it contributes significantly to the whole LRC in the Bohai Sea. Unlike the identical structure of the tide-induced LRC, the wind driven LRC varies seasonally under the prevailing monsoon. It forms a distinct gyre under the summer and winter monsoons in July and January respectively, but it seems weak and non-directional in April and September.     

黄河入海泥沙悬移输送机制的控制试验(英文)

Five diagnostic experiments with a 3D baroclinic hydrodynamic and sediment transport model ECOMSED in couple with the third generation wave model SWAN and the Grant-Madsen bottom boundary layer model driven by the monthly sediment load of the Yellow River, were conducted to separately diagnose effects of different hydrodynamic factors on transport of suspended sediment discharged from the Yellow River in the Bohai Sea. Both transport and spatio-temporal distribution of suspended sediment concentration in the Bohai Sea were numerially simulated. It could be concluded that suspended sediment discharged from the Yellow River cannot be delivered in long distance under the condition of tidal current. Almost all of sediments from the Yellow River are deposited outside the delta under the condition of wind-driven current, and only very small of them are transported faraway. On the basis of wind forcing, sediments from the Yellow River are mainly transported north-northwestward, and others which are first delivered to the Laizhou Bay are continuously moved northward. An obvious 3D structure characteristic of sediment transport is produced in the wind-driven and tide-induced residual circulation condition. Transport patterns at all layers are generally consistent with circulation structure, but there is apparent deviation between the depth-averaged sediment flux and the circulation structure. The phase of temporal variation of sediment concentration is consistent with that of the bottom shear stress, both of which are proved to have a ten-day cycle in wave and current condition.     

Diagnostic experiments for transport mechanisms of suspended sediment discharged from the Yellow River in the Bohai Sea

Five diagnostic experiments with a 3D baroclinic hydrodynamic and sediment transport model ECOMSED in couple with the third generation wave model SWAN and the Grant–Madsen bottom boundary layer model driven by the monthly sediment load of the Yellow River, were conducted to separately diagnose effects of different hydrodynamic factors on transport of suspended sediment discharged from the Yellow River in the Bohai Sea. Both transport and spatio-temporal distribution of suspended sediment concentration in the Bohai Sea were numerially simulated. It could be concluded that suspended sediment discharged from the Yellow River cannot be delivered in long distance under the condition of tidal current. Almost all of sediments from the Yellow River are deposited outside the delta under the condition of wind-driven current, and only very small of them are transported faraway. On the basis of wind forcing, sediments from the Yellow River are mainly transported north-northwestward, and others which are first delivered to the Laizhou Bay are continuously moved northward. An obvious 3D structure characteristic of sediment transport is produced in the wind-driven and tide-induced residual circulation condition. Transport patterns at all layers are generally consistent with circulation structure, but there is apparent deviation between the depth-averaged sediment flux and the circulation structure. The phase of temporal variation of sediment concentration is consistent with that of the bottom shear stress, both of which are proved to have a ten-day cycle in wave and current condition.     

大河三角洲河口海岸演化机理模型研究:(II)模型构建与实证

本文以z坐标下的三维斜压海洋动力学数值模式为基本模式原型,在整理渤海基本数据并诊断计算风生环流和热盐环流作为背景环流场基础上,初步建立了渤海海域动力环境数值模式。模式采用了经校正的Bagnold型方程来计算渤海底移质沉积物输运,悬移质计算则是取二维深度平均悬移质输运方程和河床变形方程,计算含沙量分布以及由悬移物引起的冲淤厚度。利用这种方法建立的沉积物输运模式,定量模拟了渤海沿岸和海底的沉积物输运方向和冲淤分布。模拟结果与通过多年实测水深估算获得的渤海海底沉积物的冲淤变化分布相比较,两者之间在基本结论上是比较一致的     

年代际尺度海岸演化机制与动力-统计建模方法

发展中长时间尺度的海岸演化预测方法与机理模型,是目前国际海岸演化研究领域关注的焦点和最具挑战性课题。本文系统性地回顾了近半个世纪以来不同时间尺度海岸演化模式的研究发展历程和成果,从动力机制和时间尺度两个方面对海岸演化机理模型存在的主要建模瓶颈问题进行了系统总结。通过对渤海湾西岸近一个半世纪以来海岸演化机制的初步分析,提出了以泥沙收支、环流输送、波浪掀沙以及波气候变化等要素作为年代际尺度海岸演化主要驱动因子,基于驱动力概化与统计升尺度有机衔接的年代际尺度海岸演化机理模型的动力—统计建模方法框架新思路,为推动海岸演化动力学理论体系和中长时间尺度海岸演化预测方法创新,提供了重要科学依据和借鉴。