Channel evolution under changing hydrological regimes in anabranching reaches downstream of the Three Gorges Dam

Abstract

Elucidating the influence of dams on fluvial processes can benefit river protection and basin management. Based on hydrological and topographical data, we analyzed channel evolution in anabranching reaches under changing hydrological regimes influenced by the Three Gorges Dam. The main conclusions are as follows: 1) the channels of specific anabranching reaches were defined as flood trend channels or low-flow trend channels according to the distribution of their flow characteristics. The anabranching reaches were classified as T1 or T2. The former is characterized by the correspondence between the flood trend and branch channels, and the latter is characterized by the correspondence between the flood trend and main channels; 2) on the basis of the new classification, the discrepant patterns of channel evolution seen in anabranching reaches were unified into a pattern that showed flood trend channels shrinking and low-flow trend channels expanding; 3) flood abatement and the increased duration of moderate flow discharges are the main factors that affect channel adjustments in anabranching reaches after dam construction; and 4) in the next few decades, the pattern of channel evolution will remain the same as that of the Three Gorges Dam operation. That is, the morphology will fully adapt to a flow with a low coefficient of variation. Our results are of interest in the management of the Yangtze River and other rivers influenced by dams.

Keywords

anabranching river / channel evolution / Three Gorges Dam / Yangtze River

References

[1] Abad J D, Paredes J R, Montoro H (2010). Similarities and differences between a large meandering river and an anabranching river: the Ucayali and Amazon River cases. In: 2010 Fall Meeting. San Francisco: AGU, EP24B–04

[2] Brandt S A (2000). Classification of geomorphological effects downstream of dams. Catena, 40(4): 375–401

[3] Chen J, Wang Z, Li M, Wei T, Chen Z (2012). Bedform characteristics during falling flood stage and morphodynamic interpretation of the middle-lower Changjiang (Yangtze) River channel, China. Geomorphology, 147 ‒ 148(8): 18–26

[4] Chen S P, Li Y T, Zhu L L, Sun Z H (2013). Research on river evolution mechanism of Luxikou Reach in Middle Yangtze River. J Sediment Res, 4(4): 74–80

[5] Church M (1995). Geomorphic response to river flow regulation: case studies and time scales. Regul Rivers Res Manage, 11(1): 3–22

[6] Draut A E, Logan J B, Mastin M C (2011). Channel evolution on the dammed Elwha River, Washington, USA. Geomorphology, 127(1–2): 71–87

[7] Eaton B C, Millar R G, Davidson S (2010). Channel patterns: braided, anabranching, and single-thread. Geomorphology, 120(3–4): 353–364

[8] Fang Z (1964). River type analysis and its application in river improvement. J Hydraul Eng, (1): 3–14

[9] Frias C E, Abad J D, Mendoza A, Paredes J, Ortals C, Montoro H (2015). Planform evolution of two anabranching structures in the Upper Peruvian Amazon River. Water Resour Res, 51(4): 2742–2759

[10] Gilvear D J (2004). Patterns of channel adjustment to impoundment of the upper River Spey, Scotland (1942‒2000). River Res Appl, 20(2): 151–165

[11] Grant G E, Schmidt J C, Lewis S L (2003). A geological framework for interpreting downstream effects of dams on rivers. Water Sci Appl, 7: 209–225

[12] Han J Q, Sun Z H, Feng Q F (2013). Critical features of flow dynamics at the entrance of multi-branched channels. Advances in Water Science, 24(6): 842–848

[13] Han J Q, Sun Z H, Huang Y, Li Y T (2014). Features and causes of sediment deposition and erosion in Jingjiang reach after impoundment of the Three Gorges Project. J Hydraul Eng, 45(3): 277–285

[14] Han J Q, Sun Z H, Li Y T, Yang Y (2017). Combined effects of multiple large-scale hydraulic engineering on water stages in the middle Yangtze River. Geomorphology, 298: 31–40

[15] Han Q W, He M M (1997). Tendency of river channel evolution in Yangtze River’s Middle and Lower Reaches after Three Gorges Project being completed. Journal of Yangtze River Scientific Research Institute, 14(1): 12–16 (in Chinese)

[16] Huang H Q, Deng C, Nanson G C, Fan B, Liu X, Liu T, Ma Y (2014). A test of equilibrium theory and a demonstration of its practical application for predicting the morphodynamics of the Yangtze River. Earth Surf Process Landf, 39(5): 669–675

[17] Huang H Q, Nanson G C (2007). Why some alluvial rivers develop an anabranching pattern. Water Resour Res, 43(7): 2217–2221

[18] Jain V, Sinha R (2004). Fluvial dynamics of an anabranching river system in Himalayan foreland basin, Baghmati river, north Bihar plains, India. Geomorphology, 60(1–2): 147–170

[19] Kleinhans M G, van den Berg J H(2011). River channel and bar patterns explained and predicted by an empirical and a physics-based method. Earth Surf Process Landf, 36(6): 721–738

[20] Latrubesse E M (2008). Patterns of anabranching channels: the ultimate end-member adjustment of mega rivers. Geomorphology, 101(1–2): 130–145

[21] Li L Q, Lu X X, Chen Z Y (2007). River channel change during the last 50 years in the middle Yangtze River, the Jianli reach. Geomorphology, 85(3–4): 185–196

[22] Li Z W, Li Y F, Wang Z Y, Hu S X (2016). A conceptual model of deposition and erosion of mid-channel bar head zone in anabranching river. Advances in Water Science, 27(1): 1–10

[23] Liu G W (2008). On geo-basis of river regulation—A case study for the middle reaches of the Yangtze River. Sci China Technol Sci, 51(5): 494–505

[24] Liu X F, Huang H Q, Deng C Y (2014). A theoretical investigation of the hydrodynamic conditions for equilibrium island morphology in anabranching rivers. Advances in Water Science, 25(4): 477–483

[25] Liu X F, Huang H Q, Nanson G C (2016). The morphometric variation of islands in the middle and lower Yangtze River: a variational analytical explanation. Geomorphology, 261(261): 273–281

[26] Lu Y J, Liu J M (2002). Study on fluvial process and regulations of typical shoal of middle Yangtze River. Eng Sci, 4(7): 40–45

[27] Luo X X, Yang S L, Zhang J (2012). The impact of the Three Gorges Dam on the downstream distribution and texture of sediments along the middle and lower Yangtze River (Changjiang) and its estuary, and subsequent sediment dispersal in the East China Sea. Geomorphology, 179: 126–140

[28] Mendoza A, Abad J D, Frias C E, Ortals C, Paredes J, Montoro H, Vizcarra J, Simon C, Soto-Cortés G (2016). Planform dynamics of the Iquitos anabranching structure in the Peruvian Upper Amazon River. Earth Surf Process Landf, 41(7): 961–970

[29] Ni J (1998). River Dynamic Geomorphology.Beijing: Peking University Press

[30] Rodrigues S, Bréhéret J G, Macaire J J, Moatar F, Nistoran D, Jugé P (2006). Flow and sediment dynamics in the vegetated secondary channels of an anabranching river: the Loire River (France). Sediment Geol, 186(1–2): 89–109

[31] Sanders B F, Chrysikopoulos C V (2004). Longitudinal interpolation of parameters characterizing channel geometry by piece-wise polynomial and universal kriging methods: effect on flow modeling. Adv Water Resour, 27(11): 1061–1073

[32] Smith N D, Rogers J (2009). The Role of overbank flow in governing the form of an anabranching river: the Fitzroy River, Northwestern Australia. In: Fluvial Sedimentology VI, Special Publication Number 28 International Association of Sedimentologists. Oxford: Blackwell Publishing Ltd.

[33] Sun Z H, Li Y T, Huang Y, Gao K C (2011). Fluvial process of sandbars and shoals in branching channels of the middle Yangtze River. J Hydraul Eng, 42(12): 1398–1406

[34] Xu J X (1997). Study of sedimentation zones in a large sand-bed braided river: an example from the Hanjiang River of China. Geomorphology, 21(2): 153–165

[35] Xu J X, Yan Y X (2010). Effect of reservoir construction on suspended sediment load in a large river system: thresholds and complex response. Earth Surf Process Landf, 35(14): 1666–1673

[36] 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

[37] You L Y (1984). A study on the formation and evolution of braided channel with stable island-taking the middle and lower reaches of the Yangtze River as an example. Geogr Res, 3(4): 12–24

[38] Yu W C (1994). Characteristics on hydraulic and sediment transportation of Middle and Lower Yangtze River channel-on formative conditions of braided channel. Journal of Yangtze River Scientific Research Institute, 11: 16–22(in Chinese)

[39] Zhang W, Yuan J, Han J Q, Huang C T, Li M (2016). Impact of the Three Gorges Dam on sediment deposition and erosion in the middle Yangtze River: a case study of the Shashi Reach. Hydrol Res, 47(S1): 175–186

[40] Zhu L L, Ge H, Li Y T, Zhang W (2015). Branching channels in the Middle Yangtze River, China. Journal of Basic Science and Engineering, 23(2): 246–258 (in Chinese)

Acknowledgments

This work was supported by the National Key Research and Development Plan (2016YFC0402101), the National Natural Science Foundation of China (Grant No. 51779184), the West Light Foundation of The Chinese Academy of Sciences (XAB2016B06), and the Fundamental Research Funds for the Central Universities (2452017186). The authors are grateful to the editors and anonymous reviewers for their insightful comments and suggestions.

RIGHTS & PERMISSIONS

2018 Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature