Dramatic sediment load changes and sedimentation characteristics upstream of the Three Gorges Dam due to the large reservoirs construction

Abstract

After the construction of cascade reservoirs in the upper reaches of the Three Gorges Reservoir (TGR), the sediment load outflow of the upper Yangtze River Basin (YRB) has been significantly altered, decreasing from 491.8 Mt/yr (1956–2002) to 36.1 Mt/yr (2003–2017) at Yichang station. This has widely affected river hydrology, suspended sediment grain size distribution, and channel morphology. This study analyzed hydrological variations in water discharge and sediment load of the upper YRB over the past 62 years (1956–2017) by employing a double mass curve. The variations in the source areas of sediment yielding for the upper YRB were quantified, and field measurement data of the cross-channel profile were collected to investigate the sedimentation process in the TGR from 2003 to 2017. More than 90% of the sediment load reduction in the upper YRB may be explained by human activities. The Jinshajiang River was no longer the largest sediment source area for the Zhutuo station (accounting for 5.23%) in the 2013–2017 time span, and the sediment rating rates for the inflow and outflow of the TGR shifted to negatively correlated. A longitudinal fining trend was revealed in the suspended sediment size. Still, the mean median grain size of suspended sediment in the TGR had an increasing trend in the 2013–2017 period. This result may be closely related to sediment regulation in reservoirs and incoming sediment load reduction. Sedimentation in the TGR decreased sharply from 299.8 Mt/yr in 2003–2012 to 47.2 Mt/yr in 2013–2017, but the sedimentation rate of the TGR remained at > 80% annually. Moreover, some cross sections in the fluctuating backwater zone experienced scouring.

Graphical abstract

Keywords

cascade reservoirs / sediment load / sedimentation characteristics / suspended sediment grain size / Three Gorges Reservoir

References

[1] Bhattacharyya K, Singh V P (2019). Reservoir Sedimentation: Assessment and Environmental Controls. Boca Raton: CRC Press

[2] Bi N, Sun Z, Wang H, Wu X, Fan Y, Xu C, Yang Z (2019). Response of channel scouring and deposition to the regulation of large reservoirs: a case study of the lower reaches of the Yellow River (Huanghe).J Hydrol (Amst), 568: 972–984

[3] Chongqing Water Resources Bureau (2018). Chongqing Bulletin of Soil and Water Conservation

[4] Chu P H, Liu P K, Pan H (2019). Prospects of hydropower industry in the Yangtze River Basin: China’s green energy choice.Renew Energy, 131: 1168–1185

[5] Dai Z J, Fagherazzi S, Mei X F, Gao J J (2016). Decline in suspended sediment concentration delivered by the Changjiang (Yangtze) River into the East China Sea between 1956 and 2013.Geomorphology, 268: 123–132

[6] Dai Z J, Liu J T (2013). Impacts of large dams on downstream fluvial sedimentation: an example of the Three Gorges Dam (TGD) on the Changjiang (Yangtze River).J Hydrol, 480: 10–18

[7] Dai Z J, Mei X F, Darby S E, Lou Y Y, Li W H (2018). Fluvial sediment transfer in the Changjiang (Yangtze) river-estuary depositional system.J Hydrol, 566: 719–734

[8] Guo C, Jin Z W, Guo L C, Lu J Y, Ren S, Zhou Y J (2020). On the cumulative dam impact in the upper Changjiang River: streamflow and sediment load changes.Catena, 184: 104250

[9] Guo L C, Su N, Zhu C Y, He Q (2018). How have the river discharges and sediment loads changed in the Changjiang River basin downstream of the Three Gorges Dam?.J Hydrol (Amst), 560: 259–274

[10] Hayashi S, Murakami S, Xu K Q, Watanabe M (2015). Simulation of the reduction of runoff and sediment load resulting from the Gain for Green Program in the Jialingjiang catchment, upper region of the Yangtze River, China.J Environ Manage, 149: 126–137

[11] Hu C H (2018). Study on sediment simulation and regulation techniques for Three Gorges Reservoir and its downstream reach.Water Resources Hydropower Eng, 49(1): 1–6

[12] Huang Y F, Wang J S, Yang M (2019). Unexpected sedimentation patterns upstream and downstream of the Three Gorges Reservoir: future risks.Int J Sediment Res, 34(2): 108–117

[13] Jia D D, Wang Y J, Jiang E H, Shao X J (2020). Numerical study on the sedimentation pattern of Xiaolangdi Reservoir on the Yellow River.Adv Water Sci, 31(2): 240–248

[14] Kellner E, Hubbart J A (2018). Spatiotemporal variability of suspended sediment particle size in a mixed-land-use watershed.Sci Total Environ, 615: 1164–1175

[15] Kondolf G M, Gao Y, Annandale G W, Morris G L, Jiang E, Zhang J, Cao Y, Carling P, Fu K, Guo Q, Hotchkiss R, Peteuil C, Sumi T, Wang H, Wang Z, Wei Z, Wu B, Wu C, Yang C T (2014). Sustainable sediment management in reservoirs and regulated rivers: experiences from five continents.Earths Futur, 2(5): 256–280

[16] Li D F, Lu X X, Yang X K, Chen L, Lin L (2018). Sediment load responses to climate variation and cascade reservoirs in the Yangtze River: a case study of the Jinsha River.Geomorphology, 322: 41–52

[17] Li H B, Zhang X F, Hu C H, Xu Q X (2011). Impact of cascade reservoirs construction in the upper Yangtze River on sediment inflow to Three Gorges reservoirs.J Hydroelectric Eng, 30(1): 94–100

[18] Li N, Wang L, Zeng C F, Wang D, Liu D F, Wu X T (2016). Variations of runoff and sediment load in the middle and lower reaches of the Yangtze River, China (1950–2013).PLoS One, 11(8): e0160154

[19] Li W J, Yang S F (2015). Laboratory tests on flocculation of cohesive sediment in the backwater area of the Three Gorges Reservoir.J Basic Sci Eng, 23(5): 851–859

[20] Li W J, Yang S F, Fu X H, Xiao Y (2015). Sedimentation characteristics in the Three Gorges Reservoir during the initial operation stage.Adv Water Sci, 23(5): 851–859

[21] Li W J, Yu C F, Yang S F, Yang Y P, Yang W, Xiao Y (2020). Measurements of the sediment flocculation characteristics in the Three Gorges Reservoir, Yangtze River.River Res Appl, 36(7): 1202–1212

[22] Liu J, Shen Y, Wang X (2022a). Flocculation properties of cohesive fine-grained sediment in the Three Gorges Reservoir under variable turbulent shear.J Mt Sci, 19(8): 2286–2296

[23] Liu S W, Li D X, Liu D C, Zhang X F, Wang Z L (2022b). Characteristics of sedimentation and sediment trapping efficiency in the Three Gorges Reservoir, China.Catena, 208: 105715

[24] Lu X X, Zhang S, Jiang T, Xiong M (2010). Sediment loads in the lower Jinshajiang of the Yangtze River: current status and potential impacts of the cascade dams.IAHS AISH Publ, 337: 113–120

[25] Mehta A J (1994). Problems in linking the threshold condition for the transport of cohesionless and cohesive sediment grain.J Coast Res, 10(1): 170–177

[26] Ren J, Zhao M, Zhang W, Xu Q, Yuan J, Dong B (2020). Impact of the construction of cascade reservoirs on suspended sediment peak transport variation during flood events in the Three Gorges Reservoir.Catena, 188: 104409

[27] Ren S, Zhang B, Wang W, Yuan Y, Guo C (2021). Sedimentation and its response to management strategies of the Three Gorges Reservoir, Yangtze River, China.Catena, 199: 105096

[28] Schleiss A J, Franca M J, Juez C, De Cesare G (2016). Reservoir sedimentation.J Hydraul Res, 54(6): 595–614

[29] Sirisena T A J G, Maskey S, Bamunawala J, Ranasinghe R (2021). Climate change and reservoir impacts on 21st-Century streamflow and fluvial sediment loads in the Irrawaddy River, Myanmar.Front Earth Sci, 9: 664527

[30] Steffen W, Sanderson R A, Tyson P D (2003). Global change and the earth system: a planet under pressure. EGS-AGU-EUG Joint Assembly

[31] Tang Q, Bao Y, He X, Fu B, Collins A L, Zhang X (2016). Flow regulation manipulates contemporary seasonal sedimentary dynamics in the reservoir fluctuation zone of the Three Gorges Reservoir, China.Sci Total Environ, 548–549: 410–420

[32] Tang Q, Collins A L, Wen A, He X, Bao Y, Yan D, Long Y, Zhang Y (2018). Particle size differentiation explains flow regulation controls on sediment sorting in the water-level fluctuation zone of the Three Gorges Reservoir, China.Sci Total Environ, 633: 1114–1125

[33] Tang X, Tong S, Huang G, Xu G, Li X, Lei K, Yao S (2021). Characteristics of sedimentation and channel adjustment linked to the Three Gorges Reservoir.Int J Sediment Res, 36(2): 177–189

[34] Three Gorges Sediment Specialist Group (1988). Sediments Research Compilation of the TGP: 160 m–180 m Impounding Scheme. Beijing: Science and Technology Press

[35] Wang G, Zhang J, Yang Q (2016). Attribution of runoff change for the Xinshui River catchment on the Loess Plateau of China in a Changing environment.Water, 8(6): 267

[36] Wang H J, Saito Y, Zhang Y, Bi N S, Sun X, Yang Z (2011). Recent changes of sediment flux to the western Pacific Ocean from major rivers in East and Southeast Asia.Earth Sci Rev, 108(1–2): 80–100

[37] Wei J, Hou L, He X (2014). An assessment of human versus climatic impacts on large-sized basin erosion: the case of the upper Yangtze River.Nat Hazards, 74(2): 405–420

[38] Xiao Y, Yang F S, Zhou Y J, Chen W S (2015). 1-D numerical modeling of the mechanics of gravity-driven transport of fine sediments in the Three Gorges Reservoir.Lake Reserv Manage, 31(2): 83–91

[39] Xiao Y, Zhou G, Yang F S (2016). 2D numerical modelling of meandering channel formation.J Earth Syst Sci, 125(2): 251–267

[40] Xu K H, Milliman J D (2009). Seasonal variations of sediment discharge from the Yangtze River before and after impoundment of the Three Gorges Dam.Geomorphology, 104(3–4): 276–283

[41] Xu Q X, Chen S S, Xiong M, Chen Z F (2008). Analysis on runoff and sediment characteristics and affecting factors of the Jialing River Basin.J Sediment Res, 2: 1–8

[42] Yan H C, Zhang X F, Xu Q X (2021). Variation of runoff and sediment inflows to the Three Gorges Reservoir: impact of upstream cascade reservoirs.J Hydrol (Amst), 603: 126875

[43] Yan H C, Zhang X F, Xu Q X (2022). Unprecedented sedimentation in response to emerging cascade reservoirs in the upper Yangtze River Basin.Catena, 209: 105833

[44] Yang H F, Yang S L, Meng Y, Xu K H, Luo X X, Wu C S, Shi B W (2018). Recent coarsening of sediments on the southern Yangtze subaqueous delta front: a response to river damming.Cont Shelf Res, 155: 45–51

[45] Yang S L, Milliman J D, Xu K H, Deng B, Zhang X Y, Luo X X (2014). Downstream sedimentary and geomorphic impacts of the Three Gorges Dam on the Yangtze River.Earth Sci Rev, 138: 469–486

[46] Yang S L, Xu K H, Milliman J D, Yang H F, Wu C S (2015). Decline of Yangtze River water and sediment discharge: impact from natural and anthropogenic changes.Sci Rep, 5(1): 12581

[47] Yang S L, Zhang J, Xu X J (2007). Influence of the Three Gorges Dam on downstream delivery of sediment and its environmental implications, Yangtze River.Geophys Res Lett, 34(10): L10401

[48] Zhai R, Tao F (2017). Contributions of climate change and human activities to runoff change in seven typical catchments across China.Sci Total Environ, 605–606: 219–229

[49] Zhang X F, Yan H C, Yue Y, Xu Q X (2019). Quantifying natural and anthropogenic impacts on runoff and sediment load: an investigation on the middle and lower reaches of the Jinsha River Basin.J Hydrol Reg Stud, 25: 100617

[50] Zhao Y, Zou X, Liu Q, Yao Y, Li Y, Wu X, Wang C, Yu W, Wang T (2017). Assessing natural and anthropogenic influences on water discharge and sediment load in the Yangtze River, China.Sci Total Environ, 607–608: 920–932

[51] Zhou Y J, Li D F, Lu J Y, Yao S M, Yan X, Jin Z W, Liu L, Lu X X (2020). Distinguishing the multiple controls on the decreased sediment flux in the Jialing River basin of the Yangtze River, Southwestern China.Catena, 193: 104593

Acknowledgments

This work was funded by the National Natural Science Foundation of China (Grant No. 5210090851), the Opening Fund of State Key Laboratory of Water Simulation and Safety, Tianjin University (No. HESS-1720), and the Special funded project for basic scientific research business expenses of central public welfare scientific research institutes (No. TKS 190104). We gratefully thank the captain and crew of the Changjiang Chongqing Waterway Engineering Bureau for providing cross-section topographic data. We would like to thank the Changjiang Water Resource Commission for providing hydrological data. We acknowledge those anonymous reviewers as well as the editors for constructive comments and suggestions that considerably improved this article.

Competing interests

The authors declare that they have no competing interests.

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