FLUVIAL PROCESSES IN THE LOWER JINGJIANG RIVER:IMPACT OF THE THREE GORGES RESERVOIR IMPOUNDMENT  

作　　者：XuejunSHAO HongWANG ZhaoyinWANG 

机构地区：[1]DepartmentofHydraulicEngineering,TsinghuaUniversity,Beijing100084,China；SendcorrespondencetoXuejunShao [2]DepartmentofHydraulicEngineering,TsinghuaUniversity,Beijing100084,China；SendcorrespondencetoXuejunShao [3]DepartmentofHydraulicEngineering,TsinghuaUniversity,Beijing100084,China；SendcorrespondencetoXuejunShao／／Prof.Dr.InternationalResearchandTrainingCenteronErosionandSedimentation（IRTCES）,Beijing100044,China

出　　处：《International Journal of Sediment Research》2005年第2期102-108,共7页国际泥沙研究（英文版）

基　　金：China’s National Key Basic Research and Development Program(Grant No.2003CB41 5206);the National Natural Science Foundation of China(Grant No.50179015,50221903)is gratefully acknowledged.

摘　　要：Sediment supply to the lower Jingjiang River will be subject to substantial reduction after the impoundment of the Three Gorges Reservoir,which could result in an excess of carrying capacity and serious bank erosions in the downstream alluvial channel,threatening the bank protection works and the safety of the Jingjiang Dyke. This paper presents a summary of research works concerning the fluvial processes in the lower Jingjiang River and the possible impact of the Three Gorges Reservoir impoundment on the variation of its channel pattern. Three different predictions have been put forward by researchers:1) the Jingjiang River will evolve towards a more sinuous,meandering channel pattern,with extensive bank erosion taking place along the river; 2) the river channel will be straightened and broadened because no point bar can be formed due to reduced sediment supply while bank erosion develops in the concave bank,and 3) this river reach will maintain its present channel pattern without significant change,although the sinuosity may be slightly reduced,since:a) the Three Gorges Reservoir mainly intercept sediment particles with sizes larger than 0.025mm,and b) the complex interaction between the Yangtze River and the Dongting Lake helps to reduce the negative effect of channel erosion through certain self-adjusting mechanism in fluvial processes. Discrepancy between these predictions shows that further research efforts are needed to understand the impact of Three Gorges Reservoir operation on the downstream fluvial processes. Meanwhile,there is an urgent need to closely monitor future development in the fluvial processes of the Jingjiang River and its influence on the safety of the Jingjiang Dykes.Sediment supply to the lower Jingjiang River will be subject to substantial reduction after the impoundment of the Three Gorges Reservoir,which could result in an excess of carrying capacity and serious bank erosions in the downstream alluvial channel,threatening the bank protection works and the safety of the Jingjiang Dyke. This paper presents a summary of research works concerning the fluvial processes in the lower Jingjiang River and the possible impact of the Three Gorges Reservoir impoundment on the variation of its channel pattern. Three different predictions have been put forward by researchers:1) the Jingjiang River will evolve towards a more sinuous,meandering channel pattern,with extensive bank erosion taking place along the river; 2) the river channel will be straightened and broadened because no point bar can be formed due to reduced sediment supply while bank erosion develops in the concave bank,and 3) this river reach will maintain its present channel pattern without significant change,although the sinuosity may be slightly reduced,since:a) the Three Gorges Reservoir mainly intercept sediment particles with sizes larger than 0.025mm,and b) the complex interaction between the Yangtze River and the Dongting Lake helps to reduce the negative effect of channel erosion through certain self-adjusting mechanism in fluvial processes. Discrepancy between these predictions shows that further research efforts are needed to understand the impact of Three Gorges Reservoir operation on the downstream fluvial processes. Meanwhile,there is an urgent need to closely monitor future development in the fluvial processes of the Jingjiang River and its influence on the safety of the Jingjiang Dykes.

关 键 词：Three Gorges Reservoir Downstream impact Fluvial processes Yangtze River 

分 类 号：TV697.22[水利工程—水利水电工程] P343.1[天文地球—水文科学]