scholarly journals Quasi-simultaneous measurements of suspended sediments concentration (SSC) of very turbid waters at the Yellow River Estuary with the multi-spectral HJ-1 Imageries and in-situ sampling

2014 ◽  
Author(s):  
Qianguo Xing ◽  
Mingjing Lou ◽  
Liqiao Tian ◽  
Dingfeng Yu ◽  
Federica Braga ◽  
...  
Author(s):  
Fangqiang Chang ◽  
Yonggang Jia ◽  
Hongxian Shan ◽  
Tao Liu

The silt carried by the Yellow River accumulates rapidly at the estuary to form an underwater delta, and the sediment is influenced and transformed continuously by river and ocean dynamic forces. One-meter-deep superficial sediment samples were taken at the Yellow River estuary to measure the basic physical and mechanical properties in the laboratory. The laboratory tests revealed the superficial sediment is over-consolidated and the over-consolidation ratio (OCR) reduces with depth. Soil penetration resistance was measured by a Proctor Penetrometer In-Situ. The results show the strength of superficial sediment appear to be strong non-uniformity (variation), and the strength of Xin Tan and Guang Li Gang region is less than those of the Da Wang Bei and Diao Kou. Then, the extent of soil property non-uniformity in space was calculated according to the Vanmarcke Foundation Random Theory. The vertical non-uniformity size lies between 0.32–0.93m, with little difference between those of terrestrial soils, and the horizontal lies between 12–32m, less than those on land. Finally, the reasons to cause strong non-uniformity are discussed. They are mainly composed of sediment modification by wave and biological activities.


Author(s):  
Xiu-juan Yang ◽  
Yonggang Jia ◽  
Hongxian Shan

By in situ tests, the impaction of the marine hydrodynamics, such as wave and tide, on the rapidly deposited sediments consolidation process was studied. In the tide flat of Diaokou delta-lobe, one 2m×1m×1m test pit was excavated. The fluid sediments imitating the rapidly deposited seabed silts were made in-situ, and an iron plate covered part of the test pit to cut off the effect of the marine hydrodynamics. By field-testing methods, like static cone penetration test, the variation of strength is measured at real time, and the marine hydrodynamics’ impaction on the consolidation process of the sediments in the Yellow River Estuary was studied. It is shown that the self-consolidated sediments’ strength linear increased with the depth. In the consolidation process, in the initial, marine hydrodynamics play a decisive role, about three times as much as self-consolidated in raising the strength of the sea-bed soils, and with the extension of the depth the role of the hydrodynamics reduced. With the continuation of the consolidation process, the trend of the surface sediments’ increased-strength gradually slowed under the water dynamics, while the sediments below 30cm was in opposite ways. As a result, the rapidly deposited silts present a nonuniform consolidation state, and the crust gradually formed. The results have reference in studying the role of the hydrodynamics in the soil consolidation process.


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