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Large-scale sediment and phosphorus transport in the Three Gorges Reservoir based on a new reservoir operation method
Tang, Xiaoya1,2; Zeng, Sidong1; Huang, Guoxian2; Tong, Sichen3; Qiao, Fei2; Ren, Yuanxin1; Zhang, Xingxing3
2023-09-15
摘要Change of hydrodynamic conditions is a key factor inducing sedimentation, water eutrophication and algal blooms in the Three Gorges Reservoir (TGR). How to mitigate sedimentation and phosphorus (P) retention by improving hydrodynamic conditions in the Three Gorges Reservoir area (TGRA) is an urgent issue in the study of sediment and water environment. In this study, a Hydrodynamic-Sediment-Water quality model for the whole TGRA is proposed considering sediment and P inputs from numerous tributaries, and a new reservoir operation method namely the tide-type operation method (TTOM) is used to investigate the large-scale sediment and P transport in the TGR based on the model. Results indicate that the TTOM can reduce sedimentation and total phosphorus (TP) retention in the TGR. Compared with the actual operation method (AOM), sediment outflow and sediment export ratio (Eratio) of the TGR increased about 17.13% and 1%-3% in 2015-2017, and sedimentation decreased about 3% under the TTOM. TP retention flux and retention rate (RE) decreased about 13.77% and 2%-4%. The flow velocity (V) and sediment carrying capacity (S*) increased about 40% in the local reach. Larger daily water level fluctuation at dam site is more conducive to reducing sedimentation and TP retention in the TGR. Sediment inputs from the Yangtze River, Jialing River, Wu River and other tributaries account for 59.27%, 11.21%, 3.81% and 25.70% of the total sediment inflow during 2015-2017, and TP inputs were 65.96%, 10.01%, 17.40% and 6.63%. In the paper, an innovative method is proposed to reduce sedimentation and P retention in the TGR under the given hydrodynamic conditions and related quantitative contribution driven by the proposed method is analyzed. The work is favorable for expanding the understanding of the hydrodynamic and nutrition flux changes in the TGR, and provides a new perspective for water environment protection and reasonable operation of large reservoirs.
关键词Sedimentation TP retention Three Gorges Reservoir Tide-type operation method Hydrodynamic-sediment-water quality model
DOI10.1016/j.envres.2023.116386
发表期刊ENVIRONMENTAL RESEARCH
ISSN0013-9351
卷号233页码:14
通讯作者Huang, Guoxian(huanggx@craes.org.cn)
收录类别SCI
WOS记录号WOS:001034850100001
语种英语