长江中下游深部找矿取得突破

江苏省镇江市韦岗铁矿位于长江中下游铁（铜）成矿带宁镇成矿区中段,为一隐伏高硫磁铁矿床,累计查明铁矿石总储量为1710万t。随着开采规模的逐步加大,截至2006年底,矿山保有储量为339万t,仅可维持开采4年。2006年12月,韦岗铁矿被列为全国危机矿山接替资源找矿项目。江苏省地调院承担后,在对以往该区勘查资料进行综合研究的基础上,对该矿区成矿地质条件、物探重磁异常进行分析研究,认为矿区地表以下500m～800m有较大矿体赋存的可能。2008年,项目组先后开展了坑探、磁测、钻探等工作,     

芬兰湾中的神秘群岛

看一眼列宁格勒区的地图,不难发现,芬兰湾北部沿岸的海岸线被切割得极深。大量的岛屿、礁石、半岛和海湾形成了芬诺斯坎迪亚典型的断崖地貌景观,后者被认为是芬兰湾北岸自然组合的样本。     

福建岬湾岸型沙质海滩对台风的响应特征

对福建沿岸岬湾岸型沙质海滩的蚀淤变化分析,结果表明:在0418号台风"艾利"袭击下,台风移动路径左侧的两个海滩表现为侵蚀,滩肩蚀低,滨线向陆移动,其中岩下村海滩比卒子村海滩的侵蚀严重,岩下村海滩侵蚀集中在后滨和高潮带,卒子村海滩侵蚀集中在中、低潮带;台风移动路径右侧的衙口村海滩相对比较稳定,仅中潮带出现弱淤积,后滨向陆侧人工堆积沙丘遭受侵蚀.     

沙质海岸强浪作用下沿岸输沙问题研究

在沙质海岸上修建导流堤、丁坝等会引起局部海域水沙动力条件的改变和海床冲淤调整,因此准确预测沿岸输沙率是海岸工程建设前进行优化设计的基础条件之一.首先构建了刻画高强度推移质输沙过程中固-液混合体运动的理论模型,通过寻求模型的特解并推导成1D沿岸输沙率公式.该公式适宜计算强浪作用下的推移质输沙率,已得到了大型波浪水槽、往复流水道和海滩现场实测输沙率资料的良好验证.通过与物理模型试验实测输沙量结果的比较,进一步表明该公式能够较好地预测沙质海岸在寒潮大风浪(或台风浪)作用下的高强度输沙量(骤淤量).     

长江中下游夏季降水与西北太平洋海温的耦合模态分析

利用NOAA_ERSST海温资料、NCEP/NCAR再分析资料和中国160站降水资料,借用多种统计方法研究了夏季长江中下游地区降水与西北太平洋的耦合关系.奇异值分解(SVD)和相关分析显示出长江中下游夏季降水与西北太平洋夏季海表温度(以下简称"海温")密切相关,而与其他海区没有明显的关系,并且这种关系主要反映年代际变化;夏季多变量经验正交函数展开(MV-EOF)分析结果证明夏季长江中下游降水、东亚-太平洋地区上空850hPa风场、西北太平洋海温之间存在显著的耦合模态,这种耦合模态反映出长江中下游夏季降水异常偏多时,东亚-太平洋上空自南向北有异常的反气旋、气旋、反气旋波列(即东亚-太平洋型遥相关或P-J波列),东亚夏季风偏弱、北界位置偏南.依赖季节的多变量经验正交函数展开(SRMV-EOF)分析结果表明,长江中下游夏季降水与西北太平洋的耦合模态与前期ENSO密切相关:前一年秋季,赤道东太平洋开始出现ENSO信号,冬季发展成熟,同时在菲律宾以东的西北太平洋上空有一个反气旋形成;春季,ENSO开始减弱,西北太平洋出现暖海温异常,反气旋发展;夏季,ENSO信号消失,西北太平洋异常暖海温范围扩大,反气旋发展很强,同时在东亚-太平洋上空出现P-J波列,华南上空的西南风与来自北方的偏北风在长江中下游地区辐合,造成长江中下游夏季降水偏多.     

A preliminary study of variations of the Changjiang Diluted Water between August of 1999 and 2006

A large area hypoxia has been already reported respectively by two interdisciplinary surveys off the Changjiang Estuary since summer of 1999 and 2006. The hypoxic zone shows distinct year-to-year variations. Observed oceanographic data are first analysized and reveal a big difference for the Changjiang Diluted Water (CDW) between these two periods. These great changes are related to the tremendous reduction of the freshwater discharge and variations of wind fields between these two years. It is also found that the monthly mean intrusion of Kuroshio and its branches has increased in the northern East China Sea (ECS), but decreased in the southern ECS in August of 2006 as compared with 1999 on the base of general circulation models. Then, the Regional Ocean Modelling Systems is applied to the East China Sea to evaluate the contributions and relative importance of impacts from the river discharge, wind forcing and open boundary data. Our simulations reproduce the phenomena that more fresh water extends northeastward in 2006 and forms a negative SSS anomaly to the northeast of the river mouth as compared with 1999, which is consistent with observations. The five group numerical tests suggest that the wind forcing dominates the CDW variations followed by the Kuroshio and its branches. The study implies important roles played by hydrodynamic processes on the variability of hypoxic zone in the study areas.     

Numerical Simulation of Water Level Under Interaction Between Runoff and Estuarine Dynamics in Tidal Reach of the Yangtze River

The Yangtze Estuary, the largest estuary in China, is under an obvious interaction between runoff and astronomical tide. The research on the interaction is very important for the exploitation and utilization of water resources in this area. A horizontal 2D hydrodynamic numerical model is established and verified in the present study with the modeling range from Datong to the Yangtze Estuary. Based on the comparison of high water levels under the interaction between different runoff and estuarine dynamics, s...     

The black water around the Changjiang (Yangtze) Estuary in the spring of 2003

The Changjiang (Yangtze) Estuary is located in the East China Sea shelf with shallow water. Affected by the tide mixing and the runoff of the Changjiang River and the Qiantang River, the turbidity is very high. Generally, the water-leaving radiance is high in the turbid water because of the large particle scattering. Based on the in-situ data and ocean color remote sensing data of SeaWiFS, it was found that there was a black water region with the normalized water-leaving radiances less than 0.5 mW/(cm2·μm2·...     

末次盛冰期长江南京段古河槽特征

根据南京长江大桥、三桥、四桥的地质钻孔资料,绘制南京段长江古河槽地质剖面示意图,对拟建南京长江四桥附近的4个钻孔进行了采样分析,从钻孔沉积物样品的14C年代及阶地形成时间可以判断,南京段约-60~-90 m的深槽为末次盛冰期时的长江河槽,钻孔揭示,南京段长江古河槽狭窄陡峭,呈V型,在南京长江大桥附近形成局部深切。     

长江和黄河入海沉积物不同粒级中长石/石英比值及化学风化程度评价

长石/石英(F/Q)比值是评估碎屑沉积物化学风化强度的传统指标.在长江大通站和黄河利津站及相应河口区各取9个沉积物样品,将其<125 μm的部分按1间隔分离成7组不同的粒级,用X-ray衍射法半定量分析测定了全样和不同粒级沉积物中石英和长石的相对含量,计算了长石/石英(F/Q)、钾长石/石英(Fk/Q)、斜长石/石英(Fp/Q)比值,据此评估了长江和黄河入海沉积物化学风化强度随粒级的变化.结果显示取自黄河样品的F/Q,Fk/Q和Fp/Q比值在总体上显著高于长江样品,与长江流域的化学风化强度高于黄河的结论一致,可以作为流域沉积物化学风化强度替代指标.长江样品的F/Q,Fk/Q和Fp/Q比值随粒级变细持续变低,黄河样品则呈波动式下降.黄河样品的F/Q高出长江样品的部分主要发生在＜32 μm的细粒级,在粗粒级区间差别很小,当沉积物粒级下降到一定区间后F/Q差异出现快速增加,显示长江流域沉积物的风化程度高于黄河主要发生在较细粒级.上述比值在黄河样品的2～4 μm粒级中高出长江样品3～5倍,是凸显两河化学风化强度差别的敏感粒级,也可以作为两河物源示踪的指标.