| |
| |
|
|
|
|
| |
 |
Physics of estuaries and coastal seas
|
| |
|
|
Comprehensive analyses of the sediment movement process in the vicinity of the deep-water channel of the Yangtze estuary
Tuesday 8th @ 0950-1010, Conference Hall
Qixiong Liu, College of Civil Engineering and Architecture, Zhejiang University
Haijiang Liu* , College of Civil Engineering and Architecture, Zhejiang University
Presenter Email: haijiangliu@zju.edu.cn |
| Sedimentation in the deep-water channel of the Yangtze River estuary has significantly affected the local navigation conditions. It is therefore necessary to clarify the movement of the sediment and reveal its source. We sampled the bottom sediment both in the flood (2017) and dry (2018) seasons, and analyzed the physical characteristics such as grain size, mineral composition and element composition by means of laser granulometer, polarizing microscope(PM), X-ray diffractometer (XRD)and scanning electron microscope (SEM). Probability density distribution of samples' size was obtained, the result shows clear differences between flood and dry seasons' samples. As for the flood season, sample probability density distribution presents various profiles, e.g., a multimodal, plateau, fine or coarse skewed shape. Nevertheless, the probability density curves of the dry season samples only present two types, i.e., coarse skewed and narrow-banded single peak with a large kurtosis. Subsequently, the associated parameters of sediment size such as sorting coefficient, skewness and kurtosis values were calculated by Folk and Ward formula. Results indicate that the flood season samples have larger sorting coefficient, wider range of skewness value and smaller kurtosis value. Regarding the content of magnetic minerals in sand samples, outliers were found both in the flood and dry seasons but different in locations. At the same time, through PM analysis, the samples were observed clear differences in transparency and color of different samples under the completely polarized state, which shows the difference of mineral composition in different samples. XRD is being used for further analysis of mineral composition. In addition, the SEM analysis recorded the micro-scaled image of each sample and shows the element composition of samples. Besides, several typhoons have influenced the Yangtze estuary this year. Before and after typhoons Maliya, Anbi and Suli, we sampled the bottom sediment in the vicinity of the deep-water channel of the Yangtze estuary to further study the impact of these typhoons on the suspension, transportation and deposition of sediment movement. |
|
|
|
|
|
|
|
|