Process‐based modelling of tributary mouth sandbar evolution in a high sediment‐load reservoir. (25th December 2019)

• Record Type: Journal Article
• Authors: Dou, Shentang; Yu, Xin; Zhang, Junhua; Xie, Weiming; Wang, Wanzhan; Du, Xiaokang
• Is Part Of: River research and applications. Volume 36:Number 2(2020)
• Page Start: 199
• Page End: 210
• Publication Date: 2019-12-25
• Subjects: high sediment‐load reservoir -- numerical modelling -- tributary mouth bar -- Xiaolangdi reservoir -- Yellow River; Rivers -- Regulation -- Periodicals; Rivers -- Periodicals; 551.483
• DOI: 10.1002/rra.3579
• Languages: English
• ISSNs: 1535-1459

Abstract

Abstract: Sedimentation always leads to loss of reservoir storage. This is an important issue for reservoir management, particularly for reservoirs on the Yellow River. As a result of sedimentation, sandbars are frequently found at the mouth of tributaries in reservoirs. The evolution of a tributary mouth sandbar, including its formation and scouring, plays a key role in reservoir sedimentation. However, there are few effective numerical models reported in previous studies for tributary mouth sandbar evolution in reservoirs. In this study, we propose two modules for evolution processes of mouth sandbars: one for intrusion and sedimentation and the other for scouring process. Both modules coupled turbidity current, open‐channel flow, and flow exchanges between the main stream and tributaries. Field measurements and laboratory experiments with different set‐ups were used to test the capabilities of the two proposed modules. By coupling formation and scouring modules with a 2D morphodynamic model in reservoirs, we successfully built a novel numerical model to simulate the evolution processes of tributary mouth sandbars in reservoirs. A field‐scale application of the coupled model was undertaken to simulate evolution of tributary mouth sandbars in the Xiaolangdi Reservoir, Yellow River. The results indicate that the numerical model in this study is more practical than previous models and could provide great support for optimizing reservoir operation in other systems.