Search

Your search keyword '"Ding, Pingxing"' showing total 58 results
Start Over Author "Ding, Pingxing"
58 results on '"Ding, Pingxing"'

53. Influence of the Deep Waterway Project on the Changjiang Estuary.

Author

Wolanski, Eric, Zhu, Jianrong, Ding, Pingxing, Zhang, Liquan, Wu, Hui, and Cao, Huijiang

Abstract

Using the improved 3-D ECOM model with a high resolution grid and incorporating various dynamic factors, the impact of the deep waterway project on the saltwater intrusion in the Changjiang Estuary was analysed. Salinity in the South Branch is shown to be influenced by saltwater intrusion downstream and from spillage of brackish water from the North Branch upstream. In the North Channel, the saltwater intrusion had been alleviated distinctly after the deep waterway project, because the dykes of the project blocked off the southward drift of the brackish water plumes under forcing by the northerly monsoon and the Coriolis force. The saltwater intrusion in the project area was intensified at the upper section and alleviated at the lower section. In the South passage, the saltwater intrusion was intensified as the background salinity increased and the river discharge decreased. The deep waterway project had an obvious impact on saltwater intrusion in the Changjiang Estuary. The impacts of the deep waterway project on planktons and benthos have been quantified and analyzed. The species number and biomass of planktons and benthos have decreased dramatically as compared with 20 years ago. The degradation of biodiversity at the Changjiang Estuary appears due to the cumulative impacts of eutrophication caused by human activities such as agriculture and sewage discharge, as well as land reclamation and estuarine engineering projects. [ABSTRACT FROM AUTHOR]

Published
2006
Full Text
View/download PDF

55. Estimation of critical shear stress for erosion in the Changjiang Estuary: A synergy research of observation, GOCIsensing and modeling

Author

Ge, Jianzhong, Shen, Fang, Guo, Wenyun, Chen, Changsheng, and Ding, Pingxing

Abstract

Simulating the sediment transport in a high‐turbidity region with spatially varying bed properties is challenging. A comprehensive strategy that integrates multiple methods is applied here to retrieve the critical shear stress for erosion, which plays a major role in suspended sediment dynamics in the Changjiang Estuary (CE). Time‐series of sea surface suspended sediment concentration (SSC) were retrieved from the Geostationary Ocean Color Imager (GOCI) satellite data at hourly intervals (for 8 heach day) and combined with hydrodynamic modeling of high‐resolution CE Finite‐Volume Community Ocean Model (CE‐FVCOM) to estimate the near‐bed critical shear stress in the clay‐dominated bed region (plasticity index > 7%). An experimental algorithm to determine the in situ critical shear stress via the plasticity index method was also used to verify the GOCI‐derived critical shear stress. Implemented with this new critical shear stress, the sediment transport model significantly improved the simulation of the distribution and spatial variability of the SSC during the spring and neap tidal cycles in the CE. The results suggest that a significant lateral water exchange between channels and shoals occurred during the spring flood tide, which led to a broader high‐SSC area in the CE throughout the water column. GOCI images are used to retrieve critical shear stress for erosion with observation and modelingThe retrieved result is validated with soil mechanics of field survey dataGOCI‐retrieved results provides better simulation than uniform critical shear stress

Published
2015
Full Text
View/download PDF

56. Eco-Morphological Problems in the Yangtze Estuary and the Western Scheldt.

Author

Vriend, Huib, Wang, Zheng, Ysebaert, Tom, Herman, Peter, and Ding, Pingxing

Abstract

This paper compares the Yangtze Estuary in China and the Western Scheldt Estuary in The Netherlands by their morphodynamic and ecological systems, their engineering works and estuarine management issues, and the major challenges in studying them. Physically speaking, the two estuaries are very different. The Yangtze Estuary is much larger and much more influenced by the upstream river than the Western Scheldt. Yet, they also have a number of morphological and ecological features in common. Both estuaries have a multi-channel system and extensive intertidal flats and wetlands with ecologically valuable flora and fauna. These eco-morphological systems are influenced by similar societal developments and human activities. Examples of the latter are engineering works and dredging activities for improving and maintaining the navigation channels, and shoreline management activities including land reclamations and setbacks. The fundamental eco-morphological phenomena that remain to be analysed and understood are the same for the two estuaries and will be discussed in this paper. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

57. Nonlinear unified equations for water waves propagating over uneven bottoms in the nearshore region.

Author

Huang Hu, Ding Pingxing, and Lü, Xiuhong

Subjects
*EQUATIONS, *WATER waves
Abstract

Focuses on the nonlinear unified equations for water waves propagating or uneven bottoms in the nearshore region in China. Use of Hamiltonian variational principle for water waves; Extension of Airy's nonlinear shallow-water equations; Dispersion relation for second-order Stokes wave and high order Boussinesq-type equations.

Published
2001

58. A three-dimensional mathematical transport model for suspended sediment by waves and currents.

Author

Ding Pingxing, Kong Yazhen, Zhu Shouxian, and Zhu Jianrong

Subjects
*SEDIMENT transport, *WAVES (Physics)
Abstract

Examines a three-dimensional transport model for suspended sediment by waves and current. Variation of the averaged wave and turbulence situation; Equation of suspended sediment by waves and currents; Influence of waves on current field.

Published
2001

Catalog

Books, media, physical & digital resources
See catalog results