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Tidal flat erosion of the Huanghe River Delta due to local changes in hydrodynamic conditions

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Acta Oceanologica Sinica 2014年第7期33卷 116-124页

作者： JIA Yonggang ZHENG Jiewen YUE Zhongqi LIU Xiaolei shan hongxian Key Laboratory of Marine Environment and Ecology Ministry of Education Ocean University of China First Institute of Oceanology State Oceanic Administration Key Laboratory of State Oceanic Administration for Marine Sedimentology and Environmental Geology First Institute of Oceanography State Oceanic Administration Department of Civil Engineering University of Hong Kong

An ideal nature system for the study of post-depositional submarine mass changing under wave loading was selected in the intertidal platform of the subaqueous Huanghe River Delta, a delta formed during period from 1964 to 1976 as the Huanghe River discharged into the Bohai Gulf by Diaokou distributary. A road embankment constructed for petroleum recovery on the inter-tidal platform in 1995 induced the essential varieties of hydrodynamic conditions on the both sides of the road. With both sides sharing similarities in （1） initial sedimentary environment, （2） energetic wave loading, （3） differential hydrodynamic conditions in later stages, （4） enough long-range action, and （5） extreme shallow water inter-tidal platforms; the study is representative and feasible as well. Two study sites were selected on each side of the road, and a series of measurements, samplings, laboratory experiments have been carried out, including morphometry, hydrodynamic conditions, sediment properties, granularity composition, and fractal dimension calculation of the topography in the two adjacent areas. It was observed that in the outer zone, where wave loading with high magnitude prevailed, the tidal flat was bumpy and exhibited a high erosion rate and high fractal dimension. Further, the fractal dimension diminished quickly, keeping with the enlarging of calculative square size. However in the inner zone, where the hydrodynamic condition was weak, the tidal fiat was fiat and exhibited a low erosion rate and low fractal dimensions; the fractal dimension diminished with the enlarging of calcu- lative square size. The fractal dimensions in the different hydrodynamic areas equalized increasingly as the calculative square size accreted to threshold, indicating that the hydrodynamic condition plays a significant role in topography construction and submarine delta erosion process. Additionally, the later differentiation of sediment properties, granularity composition, microstructure characteristi

关键词： hydrodynamic conditions coastal erosion sea-bed topography in-situ measurement fractal calculation

Experimental Researches on the Accuracy of Micro- Electromechanical Accelerometer-Array in Seafloor Failure Deformation Measurement

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Journal of Ocean University of China 2022年第5期21卷 1198-1204页

作者： WANG Zhenhao LIU Xiaolei ZHANG Shaotong WEN Mingzheng shan hongxian JIA Yonggang First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China Tianjin Center China Geological SurveyTianjin 300170China

At present,there are few technologies applied to in situ observation of seabed deformation,among which the micro-electromechanical accelerometer-array(hereinafter referred to as accelerometers array)is a very advantageous measurement method,with both commercial products and successful application ***,the coupling effect between accelerometer-array and sur-rounding soil and the linkage effect of accelerometer-array itself during the deformation may influence the accuracy and reliability of the measurement data.A simulation test chamber was designed and processed,and four groups of simulation tests were carried out to explore the coupling effect and linkage effect of accelerometer-array in the soil with different degree of *** results show that the accelerometer-array and the soil coupled well,and the coupling effect is positively correlated with the degree of soil *** ratio of accumulative deviation to soil lateral deformation is high at the initial stage of deformation(0-50 mm)and reduced with the continuous increase of deformation(>100 mm).In the process of liquefied soil deformation,the linkage effect of accelerometer array can be ignored,and is negatively correlated with the degree of soil consolidation.A concept to improve the measurement accu-racy of accelerometer-array in different seafloor failure deformation modes is *** research results provide references for the modification of accelerometer-array and the improvement for other flexible rod-shaped deformation sensors.

关键词： micro-electromechanical accelerometer-array seafloor failure deformation in situ observation coupling effect linkage effect

Characteristics and Causes of the Preconsolidation Stress of Soils in the Yellow River Delta

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Journal of Ocean University of China 2009年第3期8卷 215-221页

作者： YANG Xiujuan JIA Yonggang LIU Hongjun shan hongxian College of Environmental Science and Engineering Ocean University of China Qingdao 266100 P. R. China

Preconsolidation stress （ σP） is the maximum effective stress that a soil has suffered throughout its life. From a geotech- nical point of view, pre-consolidation stress has great importance because it separates elastic and reversible deformations from inelastic and only partially irreversible deformations and marks the starting point of high compressibility. In this study we calculated the preconsolidation stress for 72 undisturbed soil samples from the Yellow River Delta, using the oedometer test and applying the method proposed by Casagrande. The results showed that the over-consolidation ratio （OCR-the ratio of pre-consolidation stress to current natural overburden stress） values of the soil from soil surface to 6m depth varied from 1.72 to 15.34 and the maximum pre- consolidation stress was above 200 kPa. In consequence, the soils of the Yellow River Delta are highly over-consolidated within the upper 6m, the OCR decreasing gradually with depth from 6 to 12m. For samples from deeper than 12m the soils were found to be under-consolidated, which was proved by standard penetration tests （SPTs）. The main causes of this type of consolidation are the mineral composition and the designability of the soil body.

关键词： pre-consolidation stress Casagrande method OCR Yellow River Delta

Dynamics of Bottom Boundary Layers in the Yellow River Subaqueous Delta Based on Long-Term In-Situ Observations

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Acta Geologica Sinica(English Edition) 2017年第1期91卷 369-370页

作者： ZHU Chaoqi JIA Yonggang WANG Zhenhao GUO Lei shan hongxian LIU Xiaolei ZHANG Minsheng shandong Provincial Key Laboratory of Marine Environment and Geological Engineering (Ocean University of China) Qingdao 266100 Shandong China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and Technology Qingdao 266061Shandong China

Objective In geo-marine science,the generalized bottom boundary layer（BBL）represents a layer between sediments and *** BBL plays an important role in geological,geobiochemical,geophysical and geotechnical research b... 详细信息

关键词： Dynamics of Bottom Boundary Layers in the Yellow River Subaqueous Delta Based on Long-Term In-Situ Observations

Wave flume experiments on the contribution of seabed fluidization to sediment resuspension

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Acta Oceanologica Sinica 2018年第3期37卷 80-87页

作者： ZHANG Shaotong JIA Yonggang WANG Zhenhao WEN Mingzheng LU Fang ZHANG Yaqi LIU Xiaolei shan hongxian Key Laboratory of shandong Province for Marine Environment and Geological Engineering College of Environmental Science and Engineering Ocean University of China Functional Laboratory for Marine Geology and Environment Qingdao National Laboratory for Marine Science and Technology Key Laboratory of Ministry of Education for Submarine Geosciences and Prospecting Technology College of Marine Geosciences Ocean University of China

Sediment resuspension is commonly assumed to be eroded from the seabed surface by an excess bottom shear stress and evolves in layers from the top down. Although considerable investigations have argued the importance of wave-induced seabed fluidization in affecting the sediment resuspension, few studies have been able to reliably evaluate its quantitative contribution till now. Attempt is made to preliminarily quantify the contribution of fluidization to resuspension using a series of large-scale wave flume experiments. The experimental results indicated that fluidization of the sandy silts of the Huanghe Delta account for 52.5% and 66.8% of the total resuspension under model scales of 4/20 and 6/20（i.e., relative water depth： the ratio of wave height to water depth）, respectively. Some previously reported results obtained using the same flume and sediments are also summarized for a contrastive analysis, through which not only the positive correlation is confirmed, but also a parametric equation for depicting the relationship between the contribution of fluidization and the model scale is established. Finally, the contribution of fluidization is attributed to two physical mechanisms：（1） an attenuation of the erosion resistance of fluidized sediments in surface layers due to the disappearing of original cohesion and the uplifting effect resulting from upward seepage flows, and（2） seepage pumping of fines from the interior to the surface of fluidized seabed.

关键词： erosion shear stress seepage flows pore pressure build up fine-grained particles Huanghe Delta

Nepheloid layer generation by gas eruption:unexpected experimental results

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Journal of Oceanology and Limnology 2023年第2期41卷 769-777页

作者： Chaoqi ZHU Sanzhong LI Jiangxin CHEN Dawei WANG Xiaoshuai SONG Zhenghui LI Bo CHEN hongxian shan Yonggang JIA shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Key Lab of Submarine Geosciences and Prospecting TechniquesMinistry of Education(MOE)Ocean University of ChinaQingdao 266100China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China Frontiers Science Center for Deep Ocean Multispheres and Earth System and College of Marine GeosciencesOcean University of ChinaQingdao 266100China Hainan Key Laboratory of Marine Geological Resources and Environment Haikou 570206China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266061China Key Laboratory of Gas Hydrate Ministry of Natural ResourcesQingdao Institute of Marine GeologyQingdao 266061China Laboratory of Marine Geophysics and Georeource Institute of Deep-Sea Science and EngineeringChinese Academy of SciencesSanya 572000China

Knowledge of nepheloid layers is important to improve the understanding of physical,geological,and sedimentary processes from continental shelf to abyssal *** had not tried to study the nepheloid layers in a hydrate-associated tank until unexpected results *** experimental results show that gas eruptions triggered intermediate nepheloid ***,we proposed a new mechanism of intermediate nepheloid layer generation by *** intermediate nepheloid layers were generated in uniform-density fluid,which indicated that stratified fluid is not a necessary condition for intermediate nepheloid *** space for advection and an oblique slope for detachment are the key ingredients for intermediate nepheloid layer generation by *** experiments also offer a new experimental evidence for bottom nepheloid layer generation by *** the scale effects of laboratory experiment,it is important to determine whether submarine volcanic eruption or hydrate-associated venting causes intermediate nepheloid layer in the nature.

关键词： intermediate nepheloid layer gas eruption bottom nepheloid layer gas hydrate tank experiment seafloor instability

The fractal characteristic change in the Huanghe River Estuary due to the hydrodynamic conditions’variation

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Acta Oceanologica Sinica 2003年第2期22卷 191-200页

作者： Jia Yonggang, Fu Yuanbin, Xu Guohui, shan hongxian, Cao Xueqing Environmental Engineering Department, Ocean University of China, Qingdao 266003,China Environmental Engineering Department Ocean University of China Qingdao 266003 China

The study area lies in the subaqueous delta, which came into being in 1964 - 1976. Oneoil-field road has been built for exploring petroleum to form a wave barrier. The hydrodynarnic conditions on the north side of the road are relatively violent, on the contrary the hydrodynarnic conditions on the south side of the road are nearly placid. This makes the study area a natural laboratory for studying the influence of the hydrodynarnic conditions on the fractal characteristics of the tidal flat. Selecting an area is named Case Ⅰ on the side of stronger hydrodynarnic activities and an area is named Case Ⅱ on the other side. Measuring the topography and sampling and analyzing the granulometrical composition, it is found that the hydrodynarnic conditions have fatal influence on the surface fractal dimensions and the granulometrical fractal dimensions of the area. In Case Ⅰ , which has strong hydrodynarnic conditions, the surface fractal dimensions are obviously larger than those of Case Ⅱ , and the granulometrical fractal dimensions are relatively smaller than those of Case Ⅱ , the surface fractal dimensions of Case Ⅰ decrease quickly with the increase of grid size; the granulometrical fractal dimensions are disperse, while the hydrodynarnic conditions of Case Ⅱ are just reverse. A sampling line and a core sampling on each side of the road are selected. It is found that on the south side of the road the granulometrical fractal dimensions vary regularly in the line and with the depth, the farther apart from the road, the smaller the fractal dimensions, and the deeper the sampling position the larger the fractal dimensions, while granulometrical fractal dimensions on the north side of the road have no such regularity pattern. The mechanism of the influence of the hydrodynarnic conditions on the fractal characteristics is discussed.

关键词： Tidal-flat hydrodynamic conditions surface fractal dimensions granulometrical fractal dimensions Huanghe River Estuary

Release of Mercury from Intertidal Sediment to Atmosphere in Summer and Winter

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Chinese Geographical Science 2010年第2期20卷 99-105页

作者： LIU Ruhai Under the auspices of National Natural Science Foundation of China （No. 40806045） the Program of the State Bureau of Oceanic Administration （No. 908-02-02-03） WANG Yan shan Changqing Ling Min shan hongxian Ministry of Education Key Laboratory of Marine Environment and Ecology Ocean University of China Qingdao 266100 China Department of Urban and Environment Binzhou Universtiy Binzhou 256600 China

The release of mercury from intertidal sediment to atmosphere was studied based on the simulated experiment. The experiment samples were collected from the Haibo Estuary (S1) and the Licun Estuary (S2) of the Jiaozhou Bay in China,which are seriously polluted with mercury. The results show that the mercury in sediment releases rapidly to atmosphere under solar radiation. After 8 hours of solar radiation,mercury concentrations decrease from 5.62 μg/g and 2.92 μg/g to 2.34 μg/g and 1.39 μg/g in S1 and S2 sediments respectively in summer,and decrease from 5.62 μg/g and 2.92 μg/g to 4.58 μg/g and 2.13 μg/g respectively in winter. The mercury species in the sediment change markedly under solar radiation. The concentrations of mercury bound to organic matter decrease significantly from 2.73 μg/g to 0.31 μg/g in S1 and from 2.07 μg/g to 0.31 μg/g in S2,and the released mercury mainly comes from mercury bound to organic matter. Mercury flux shows distinguishing characteristic of diurnal change,and it increases rapidly in the morning with the rising of solar radiation intensity,but decreases in the afternoon. The mercury flux increases with sediment temperature and solar radiation intensity. The rapid release of mercury in intertidal sediment plays an important role in the regional mercury cycle.

关键词： mercury intertidal sediment mercury release solar radiation mercury species

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胶州湾近岸沉积物-海水汞的释放研究

海洋湖沼通报 2006年第4期 44-51页

作者：单长青刘汝海单红仙中国海洋大学海洋环境与生态教育部重点实验室青岛266003

本文通过模拟实验研究了胶州湾海泊河口和李村河口沉积物中的汞在不同环境条件下向海水的释放，并对汞的释放动力学数据进行了拟合。总体上两种沉积物汞的释放浓度分别为1.41～5．99μg／L和1．06～3．62μg／L，最大释放率分别为2．7％... 详细信息

本文通过模拟实验研究了胶州湾海泊河口和李村河口沉积物中的汞在不同环境条件下向海水的释放，并对汞的释放动力学数据进行了拟合。总体上两种沉积物汞的释放浓度分别为1.41～5．99μg／L和1．06～3．62μg／L，最大释放率分别为2．7％和3．4％，对胶州湾潮间带水质产生较大的影响。海水的pH值、温度和沉积物厚度都会影响汞的释放。pH〈时,汞的释放作用随pH值的升高而降低，pH〉7时．汞的释放作用随pH值的升高而增大；海水温度越高．汞的释放作用越强；随沉积物厚度的增加．汞的释放量增加，释放率降低，海泊河口和李村河口沉积物的有效厚度分别为3．5cm和2．5cm。汞的释放动力学拟合结果表明多个方程都能较好的描述汞的释放动力学过程．其中以Ho的二级动力学方程拟合结果最好。

关键词：胶州湾沉积物汞释放