检索结果-南通市图书馆

Grain-Size Distribution of Surface sediments in the Bohai Sea and the Northern Yellow Sea: sediment supply and Hydrodynamics

引用

Journal of Ocean University of China 2020年第3期19卷 589-600页

作者： YUAN Ping WANG Houjie WU Xiao BI Naishuang College of Marine Geosciences/Key Laboratory of Submarine Geosciences and Prospecting Techniques MOEOcean University of ChinaQingdao 266100China Laboratory of Marine Geology Qingdao National Laboratory of Marine Science and TechnologyQingdao 266237China

The grain-size distribution of surface sediments in the Bohai Sea(BS) and the northern Yellow Sea(NYS), and its relationship with sediment supply and hydrodynamic environment were investigated based on grain-size compositions of surface sediments and modern sedimentation rates. The results showed that the surface sediments in the BS and the NYS were primarily composed of silty sand and clayey silt with a dominant size of silt. In addition, the Yellow River delivered high amount of water and sediments to the BS, and they are dominated in surface sediments(mainly silt) in the Bohai Bay, the Yellow River mouth, the center of the BS, and the north coast of Shandong Peninsula. The coarse-grained sediments were mainly deposited at the river mouth due to the estuarine filtration and physical sorting. Meanwhile, there was a significant relationship among the modern sedimentation rate, the surface sediment grain size distribution and sediment transport pattern. The areas with coarser surface sediments generally corresponded low sedimentation rates because of strong erosion;whereas the sedimentation rate was relatively high at the place that the surface sediments were fine-grained. Furthermore, the grain-size trend analysis showed that the areas with fine-grained surface sediments such as the mud area in the central BS and the upper Liaodong Bay were the convergent centers of surface sediments, except for the Bohai Bay and the subaqueous Yellow River Delta where offshore sediment transport was evident.

关键词： Bohai Sea and North Yellow Sea surface sediment grain size sedimentation rate sediment supply sedimentary dynamic environment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of sediment supply on Spartina Salt Marshes

引用

Pedosphere 2008年第5期18卷 593-598页

作者： SHEN Yong-Ming YANG Jing-Song WANG Yan-Hong FENG Nian-Hua ZHOU Qin ZENG Hua Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China）. Department of Geography Nanjing Xiaozhuang College Nanjing 210097 （China） River and Harbor Engineering Department Nanjing Hydraulic Research Institute Nanjing 210024 （China）

During the past century,natural and human modifications of environmental systems have greatly accelerated coastal salt marsh deterioration and shoreline retreat in many regions worldwide. Field investigation,profile analysis,geographical information analysis,and remote sensing were employed in combination to study the effect of sediment on Spartina alterniflora salt marshes of the coast in Jiangsu Province,East China. The results indicated that the propagation of Spartina alterniflora salt marshes was closely related to regional sediment conditions,especially the supply of fine-grained materials. Additionally,because of the dense and high grass in Spartina alterniflora salt marshes,wave energy and tidal currents were baffled and weaker than those of the adjacent,unvegetated mud flats. Fine sediment was hardly resuspended under the low energy conditions in the Spartina alterniflora salt marshes.

关键词： cost salt marsh sediment supply Spartina alterniflora tidal mud flat

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Time lag between reduction of sediment supply and coastal erosion

引用

International Journal of sediment Research 2011年第1期26卷 27-35页

作者： HUANG Guangwei~1 University of Tokyo,Japan, [a] Dr. University of Tokyo Japan

The disruption of sediment supply from river to coast by dam development has been a topic of global *** Japan,among the top 30 dams in terms of height,14 dams were constructed prior to 1970 and another 6 dams before ***,the coastline erosion did not surface up as a grievous problem until the *** to the River Bureau of Japan,the overall erosion rate along the coastline of Japan was 0.72×10~6 m~2/yr prior to 1980,but sharply increased to 1.6×10~6 m~2/yr since ***,there was a time lag between the disruption of sediment supply by dam and beach *** paper presents a case study on what may have delayed the response of beach to the effect of dam construction.

关键词： Erosion sediment supply Dam Sand mining Time lag

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Flow variability along a vegetated natural stream under various sediment transport rates

引用

Journal of Mountain Science 2018年第11期15卷 2347-2364页

作者： WANG Hai-zhou Xu Ze-xing Yu Hai-ti WANG Xie-kang State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

The influence of vegetation and sediment on flow characteristics in open channels cannot be neglected. To study the flow variability under the effects of the instream natural vegetation and sediment supply, experiments were conducted with varied water and sediment supply in a movable bed of a river prototype. The instantaneous threedimensional velocities near two types of vegetation patches(the shrub and the weed) and along the centerline of the main channel with vegetation belts were measured using a 3-D side-looking acoustic Doppler velocimetry. The experimental results show that both the instream vegetation and sediment supply strongly affect the flow and turbulence characteristics. In the case of vegetation patches, both the shrub and weed have a considerable influence on the distribution of the streamwise velocity and turbulence intensity of their surrounding water. The streamwise velocity distribution followed as J-shape and linear shape around the weed and shrub under different experimental conditions. The turbulence intensity was large at the top of the weed and shrub;the shrub had its greatest influence on the downstream water flow. In the case of vegetation belts,the streamwise velocity along the centerline of the main channel exhibited an S-shape, J-shape and linear shape at different locations under varied water,vegetation structures and riverbed *** turbulence intensity along the centerline of the main channel ranged from 0.0 to 0.1. The upstream turbulence intensity was affected considerably by a sediment supply, while the downstream turbulence intensity changed with the varied vegetation characteristics and riverbed topography. The second flow coefficient M-value increased longitudinally and was almost positive along the centerline of the main channel, implying that the rotational direction of the secondary current cell was clockwise.

关键词： Natural vegetation sediment supply Velocity profile Turbulence intensity Secondary flow Movable bed

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of incoming sediment on the transport rate of bed load in mountain streams

引用

International Journal of sediment Research 2009年第3期24卷 260-273页

作者： Guo-An YU1, Zhao-Yin WANG2, Kang ZHANG3, Tung-Chiung CHANG4, and Huaixiang LIU51 Dr., Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China and Dept. of Hydraulic Engineering, Tsinghua University, 2 Prof., State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100101, China, 3 Ph.D. candidate, State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China 4 Ph.D. candidate, Tsinghua University, Beijing 100084, China and Prof., Kaoyuan University, Kaohsiung 82151, Taiwan, China 5 Dr., State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China [a] Dr. Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China and Dept. of Hydraulic Engineering Tsinghua University [b] Prof. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100101 China [c] Ph.D. candidate State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China [d] Ph.D. candidate Tsinghua University Beijing 100084 China and Prof. Kaoyuan University Kaohsiung 82151 Taiwan China [e] Dr. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

Field experiments were conducted on bed load transport in the Diaoga River, a mountain stream in southwest China, to study the variation of bed load transport with varying sediment supply. The rate of bed load transport is greatly affected by incoming sediment (load and size). Under the same flow conditions, bed load transport rates may differ by three orders of magnitude depending on whether measurements were taken before or after the first flood of the year. The relation of the "bed load transport rate versus flow intensity" appears to have similar characteristics as a clockwise looped-rating curve. Experiments also were conducted during the non-flood season to study bed load transport processes with different incoming load from an upstream section. Bed load with different sizes can be grouped into two types: traveling bed load and structural bed load. Traveling bed load is composed of sediment finer than a critical size, Dc, and its transport rate depends mainly on the incoming sediment rate. The incoming sediment rate can alter the rate of bed load transport by three orders of magnitude. Structural bed load is composed of coarser sediment and its transport rate closely relies on the flow intensity.

关键词： Mountain streams Bed load transport sediment supply sediment size distribution

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

High-Resolution Transgressive-Regressive Sequence Stratigraphy of Chang 8 Member of Yanchang Formation in Southwestern Ordos Basin,Northern China

引用

Journal of Earth Science 2010年第4期21卷 423-438页

作者：吕明胜陈开远薛良清衣丽萍朱红涛 Research Institute of Petroleum Exploration & Development PetroChina School of Energy Resources China University of Geosciences China National Oil and Gas Exploration and Development Corporation Faculty of Earth Resources China University of Geosciences

The reservoirs within the Chang 8 Member of Yanchang(延长) Formation in the southwestern Ordos basin are characterized by low *** is significant to build a high-resolution sequence stratigraphic framework for the exploration and development of these *** on an integrated investigation of well logs,seismic data,cores and outcrops,the Chang 8 Member is interpreted as a 3rd-order transgressive-regressive(T-R) sequence,which consists of six 4th-order T-R sequences,namely,K1,K2,K3,K4,K5 and K6,respectively,from base to *** 4th-order sequence comprises a transgressive systems tract overlain by a regressive systems *** K1 to transgressive systems tract of K4,it is characterized by the landward shifts of facies and overall retrogradational sequence stacking pattern due to accommodation increase more than sediment supply during the 3rd-order base-level *** distributary channels are mainly deposited in the transgressive systems tracts,and the interdistributary bays,sheet sands,and small-scale mouth bars are primarily developed in the regressive systems tracts in response to the 4th-order base-level *** the regressive systems tracts of K4 to K6,it is characterized by the basinward shifts of facies and overall progradational sequence stacking pattern because of accommodation increase less than sediment supply during a fall in 3rd-order base *** distributary channels are mainly accumulated in the transgressive systems tracts,and distributary channels and mouth bars are deposited in the regressive systems tracts as a result of the 4th-order base-level *** stratigraphic and sedimentological analyses indicate that sequences K1,K2,K5 and K6,as well as the basin edge of K3 and K4,remain potential for exploration and development due to their high reservoir quality in response to the low accommodation and more sediment supply.

关键词： transgressive-regressive sequence base level sediment supply sequence stratigraphic framework Ordos basin.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Controlling factors on the submarine canyon system: A case study of the Central Canyon System in the Qiongdongnan Basin, northern South China Sea

引用

Science China Earth Sciences 2014年第8期57卷 2457-2468页

作者： SU Ming ZHANG Cheng XIE XiNong WANG ZhenFeng JIANG Tao HE YunLong ZHANG CuiMei Laboratory of Gas Hydrate Formation Mechanism Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Guangzhou Center for Gas Hydrate Research Chinese Academy of Sciences Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of Geosciences China National Offshore Oil Zhanjiang Ltd. Corporation Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences

Based on an integrated analysis of high-resolution 2D/3D seismic data and drilling results, this study analyzes the tectonic- sedimentary evolution of the Qiongdongnan Basin （QDNB） since the late Miocene, and discusses the controlling factors on the formation and development of the Central Canyon System （CCS）. The sediment failures caused by the relative sea level falling might have discharged deposits from the slope to the canyon. The two suits of the infillings, i.e., turbidites and mass transport complex （MTC）, were derived from the northwestern source and northern source, respectively. The sediment supplies, which differ significantly among different areas, might have led to the variations observed in the internal architectures. Tectonic transformation around 11.6 Ma had provided the tectonic setting for the CCS and formed an axial sub-basin in the central part of the Changchang Depression, which could be called the rudiment of the CCS. The tectonic activity of the Red River Fault （RRF） at about 5.7 Ma might have strengthened the hydrodynamics of the deposits at the junction of the Yinggehal Basin （YGHB） and the QDNB to trigger a high-energy turbidity current. The MTC from the northern continental slope system might have been constrained by the Southern Uplift, functioning as a barrier for the infillings of the CCS. Thanks to a sufficient sediment supply during the Holocene period and the paleo-seafloor morphology, the relief of modern central canyon with the starving landform in the eastern Changchang Depression might have been accentuated by deposition of sediments and vertical growth along the canyon flanks, where collapse deposits were widely developed. Corresponding to the segmentation of the CCS, the forming mechanisms of the canyon between the three segments would be different. The turbidite channel in the head area had likely been triggered by the abundant sediment supply from the northwestern source together with the fault activity at about 5.7 Ma of th

关键词： submarine canyon system relative sea level change sediment supply tectonic activity Qiongdongnan Basin

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

1984-2019年环渤海滩涂遥感提取及时空演化分析

引用

Journal of Geographical Sciences 2023年第1期33卷 76-98页

作者：徐海珏贾奥宋晓龙白玉川 State Key Laboratoryof Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300350China Institute for sedimentation on Riverand Coastal Engineering Tianjin UniversityTianjin 300350China

Tidal flats, a precious resource that provides ecological services and land space for coastal zones, are facing threats from human activities and climate change. In this study, a robust decision tree for tidal flat extraction was developed to analyse spatiotemporal variations in the Bohai Rim region during 1984–2019 based on 9539 Landsat TM/OLI surface reflection images and the Google Earth Engine(GEE) cloud platform. The area of tidal flats significantly fluctuated downwards from 3551.22 to 1712.36 km^(2) in the Bohai Rim region during 1984–2019, and 51.31% of tidal flats were distributed near the Yellow River Delta and Liaohe River Delta during 2017–2019. There occurred a drastic spatial transition of tidal flats with coastline migration towards the ocean. Low-stability tidal flats were mainly distributed in reclamation regions, deltas, and bays near the estuary during 1984–2019. The main factors of tidal flat evolution in the Bohai Rim region included the direct impact of land cover changes in reclamation regions, the continuous impact of a weakening sediment supply, and the potential impact of a deteriorating sediment storage capability. The extraction process and maps herein could provide a reference for the sustainable development and conservation of coastal resources.

关键词： Bohai Rim tidal flats remote sensing spatiotemporal evolution reclamation sediment supply

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：