Bank retreat processes and characteristics in the Jingjiang Reach after the Three Gorges Project operation
XIA Junqiang1, LIN Fenfen1, ZHOU Meirong1, DENG Shanshan1, PENG Yuming2
1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China; 2. Jingjiang Bureau of Hydrology and Water Resources Survey, Changjiang Water Resources Commission, Jingzhou 434020, China
Abstract：The Jingjiang Reach is undergoing considerable channel degradation, and significant bank retreat processes have occurred at local sites due to the operation of the Three Gorges Project (TGP). By investigating the adjustments in planform and cross-sectional geometries based on the measured topographic and hydrological data after the TGP operation, it is discovered that the process of bankline migration was remarkable in the Jingjiang Reach, with the average annual bank-erosion rate of 15.0 m/a and the cumulative bank-erosion length of 42.3 km; 59.2% of the bank-erosion regions were located at the left bank, and 68.7% of them were located in the Lower Jingjiang Reach (LJR); and severe bank retreat processes also occurred at convex banks, with 35.5% of the bank-erosion regions in the LJR. In addition, the variation in cross-sectional profiles indicates that 21% of all the cross-sections underwent obvious bank retreat processes, of which 74% occurred in the LJR. In summary, the bank-erosion regions were mainly located at the left bank and the bank retreat intensity was much higher in the LJR. Various factors influencing bank retreat in the Jingjiang Reach have been presented, and the results indicate that the incoming flow-sediment regime is a dominant control factor. Finally, empirical relationships were developed between the section-scale bankfull widths at typical sections with severe bank retreat and the previous five-year average fluvial erosion intensity during flood seasons, with the correlation coefficients of being higher than 0.85. Therefore, the proposed empirical relations can better consider the effect of the altered flow and sediment regime on the variation in bankfull widths at typical sections.
夏军强, 林芬芬, 周美蓉, 邓珊珊, 彭玉明. 三峡工程运用后荆江段崩岸过程及特点[J]. 水科学进展, 2017, 28(4): 543-552.
XIA Junqiang, LIN Fenfen, ZHOU Meirong, DENG Shanshan, PENG Yuming. Bank retreat processes and characteristics in the Jingjiang Reach after the Three Gorges Project operation. Advances in Water Science, 2017, 28(4): 543-552.
余文畴, 卢金友. 长江河道崩岸与护岸[M]. 北京:水利水电出版社, 2008:80-102. (YU W C, LU J Y. Bank erosion and protection in the Yangtze River[M]. Beijing:China Water & Power Press, 2008:80-102. (in Chinese))
[2]
XIA J Q, DENG S S, LU J Y, et al. Dynamic channel adjustments in the Jingjiang Reach of the middle Yangtze River[J]. Scientific Reports, 2016, 6:22802.
[3]
XIA J Q, DENG S S, ZHOU M R, et al. Geomorphic response of the Jingjiang Reach to the Three Gorges Project operation[J]. Earth Surface Processes and Landforms, 2016.[doi:10.1002/esp.4043]
[4]
曹广晶, 王俊. 长江三峡工程水文泥沙观测与研究[M]. 北京:科学出版社, 2015:809-815. (CAO G J, WANG J. Measurements and studies of hydrological and sediment data in the Three Gorges Project[M]. Beijing:Science Press, 2015:809-815. (in Chinese))
[5]
夏军强, 宗全利, 许全喜, 等. 下荆江二元结构河岸土体特性及崩岸机理[J]. 水科学进展, 2013, 24(6):810-820. (XIA J Q, ZONG Q L, XU Q X, et al. Soil properties and erosions mechanisms of composite riverbanks in Lower Jingjiang Reach[J]. Advances in Water Science, 2013, 24(6):810-820. (in Chinese))
[6]
夏军强, 王光谦, 吴保生. 黄河下游河床纵向与横向变形的数值模拟[J]. 水科学进展, 2003, 14(4):389-395. (XIA J Q, WANG G Q, WU B S. Numerical simulation for the longitudinal and lateral deformation of riverbed in the lower Yellow River[J]. Advances in Water Science, 2003, 14(4):389-395. (in Chinese))
[7]
JIA D D, SHAO X J, WANG H, et al. Three-dimensional modeling of bank erosion and morphological changes in the Shishou bend of the middle Yangtze River[J]. Advances in Water Resources, 2010, 33(3):348-360.
[8]
假冬冬, 张幸农, 应强, 等. 流滑型崩岸河岸侧蚀模式初探[J]. 水科学进展, 2011, 22(6):813-817. (JIA D D, ZHANG X N, YING Q, et al. Preliminary study on the analytical model for slide collapse of riverbanks[J]. Advances in Water Science, 2011, 22(6):813-817. (in Chinese))
[9]
张幸农, 陈长英, 假冬冬, 等. 渐进坍塌型崩岸的力学机制及模拟[J]. 水科学进展, 2014, 25(2):246-252. (ZHANG X N, CHEN C Y, JIA D D, et al. Mechanisms of gradual riverbank collapses and simulation study[J]. Advances in Water Science, 2014, 25(2):246-252. (in Chinese))
[10]
余明辉, 陈曦, 魏红艳, 等. 不同近岸河床组成情况下岸坡崩塌试验[J]. 水科学进展, 2016, 27(2):176-185. (YU M H, CHEN X, WEI H Y, et al. Experimental of the influence of different near-bank riverbed compositions on bank failure[J]. Advances in Water Science, 2016, 27(2):176-185. (in Chinese))
[11]
LAWLER D M, GROVE J R, COUPERTHWAITE J S, et al. Downstream change in river bank erosion rates in the Swale-Ouse system, northern England[J]. Hydrological Processes, 1999, 13(7):977-992.
[12]
XIA J Q, LI T, LI X J, et al. Daily bank erosion rates in the lower Yellow River before and after dam construction[J]. Journal of the American Water Resources Association, 2014, 50(5):1325-1337.
[13]
宗全利, 夏军强, 许全喜, 等. 上荆江河段河岸土体组成与分布分析及岸坡稳定性计算[J]. 水力发电学报, 2014, 33(2):168-178. (ZONG Q L, XIA J Q, XU Q X, et al. Soil composition analysis and slope stability calculation of riverbanks in the upper Jingjiang Reach[J]. Journal of Hydroelectric Engineering, 2014, 33(2):168-178. (in Chinese))
[14]
钱宁, 张仁, 周志德. 河床演变学[M]. 北京:科学出版社, 1987:171-172. (CHIEN N, ZHANG R, ZHOU Z D. Fluvial processes[M]. Beijing:Science Press, 1987:171-172. (in Chinese))
[15]
卢金友, 渠庚, 李发政, 等. 下荆江熊家洲至城陵矶河段演变分析与治理思路探讨[J]. 长江科学院院报, 2011, 28(11):113-118. (LU J Y, QU G, LI F Z, et al. Channel evolution of the reach from Xiongjiazhou to Chenglingji in Lower Jingjiang River and regulation considerations[J]. Journal of Yangtze River Scientific Research Institute, 2011, 28(11):113-118. (in Chinese))
[16]
朱玲玲, 许全喜, 熊明. 三峡水库蓄水后下荆江急弯河道凸冲凹淤成因[J]. 水科学进展, 2017, 28(2):193-202. (ZHU L L, XU Q X, XIONG M. Fluvial processes of meandering channels in the Lower Jingjiang River reach after the impoundment of Three Gorges Reservior[J]. Advances in Water Science, 2017, 28(2):193-202. (in Chinese))
[17]
POLLEN N, SIMON A. Enhanced application of root-reinforcement algorithms for bank-stability modeling[J]. Earth Surface Processes and Landforms, 2014, 34(4):471-480.
[18]
肖培青, 姚文艺, 王国庆, 等. 植被作用下土壤抗剪强度和径流侵蚀力的耦合效应[J]. 水科学进展, 2016, 27(2):224-230. (XIAO P Q, YAO W Y, WANG G Q, et al. Effects of soil shear strength and runoff erosivity on slopes with different vegetation cover[J]. Advances in Water Science, 2016, 27(2):224-230. (in Chinese))
[19]
WU B S, XIA J Q, FU X D, et al. Effect of altered flow regime on bankfull area of the lower Yellow River, China[J]. Earth Surface Processes and Landforms, 2008, 33(10):1585-1601.
2017, Vol. 28 
