Three-dimensional numerical model under changing environment in Lower Reaches of the Yellow River

---

Xiaonan Li, Deyu Zhong, Yong Qiang Wang, Hongwu Zhang

Sunday 28 june 2015

18:00 - 18:03h at Europe 1 & 2 (level 0)

Themes: (T) Water engineering, (ST) Computational methods

Parallel session: Miscalleneous

---

This paper aims at investigating the characteristics of water and sediment transport under changing environment in Lower Reaches of the Yellow River through three-dimensional numerical model. Based on the hydrodynamic model of SELFE, the sediment transport module is added to form a complete system of water and sediment transport. Here the suspended-load transport is simulated through the equation of convective-diffusion, which are solved in finite-volume method with total variation diminishing (tvd) scheme to guarantee conservation. The bed-load transport is simulated in a non-equilibrium method and sorting of bed material is also considered. Then the three-dimensional model based on unstructured grid is used to study characteristics of water and sediment transport between the Hua-yuankou & Ai-shan in Lower Reaches of the Yellow River. In this study, to reflect the changing environment, on the one hand different conditions of incoming water and sediment are adopted. On the other hand, different patterns of river regulation are considered, for instance, the pattern of present status and the pattern of clearing sands with converging flow. Therefore, multiple numerical tests are carried in this study, which mainly focus on the character of the flood propagation, sediment transport, river-bed deformation, amount of riverbed erosion and deposition in the whole reach as well as typical reaches’ flow characteristics. The results not just show good agreement with the measured data, but also clearly reveal the response characteristics of water and sediment transport under changing environment. According to numerical calculation results, powerful support is provided for the patterns of river regulation in Lower Reaches of the Yellow River.