三峡工程蓄水后荆江沙质河段河床演变及对航道的影响  

Channel Evolution of Jingjiang Reach and Its Influences on Waterway After Impoundment of the Three Gorges Project

作　　者：江凌 李义天[2] 孙昭华[2] 黄成涛 

机构地区：[1]长江航道规划设计研究院,湖北武汉430011 [2]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《应用基础与工程科学学报》2010年第1期1-10,共10页Journal of Basic Science and Engineering

基　　金：国家973项目资助;国家自然科学基金重点资助项目(50609018)

摘　　要：分析了三峡工程蓄水以来荆江沙质河段不同类型河床的演变特性,预测计算了水库下游河床冲刷过程,进而探讨了河床演变趋势及其对航道的影响.资料分析表明,蓄水初期,上荆江深泓下切明显,但分汊放宽段航深不足问题突出;下荆江深泓冲淤相间,长顺直(微弯)河段的深槽过渡段下移,弯道进口处水流较分散,致使航槽不稳定.基于数学模型计算结果预测,蓄水5—10年,太平口—藕池口河段发生强烈冲刷,分汊放宽段中枯水河槽更宽浅,致使航道条件恶化,而且,支汊发展会影响主汊的通航条件;藕池口以下处于冲刷初期,过渡段浅滩碍航与否主要与退水过程有关,但弯道发展将使航槽位置发生变动.蓄水15—20年,藕池口以上冲刷基本完成,上荆江微弯分汊河型趋于稳定;藕池口以下发生强烈冲刷,过渡段浅滩高程降低,有利于航深的增加,弯道可能出现局部撇弯,致使航槽移位.The article respectively analyses the channel evolution characteristics of different plan-form reaches since the Three Gorges Project （TGP） impounded water, calculates the bed erosion process downstream the reservoir by 1-D numerical model, and discusses the trend of channel evolution and influences on the waterway. Data analysis indicates, at the initial stages of TGP＇s impoundment, the Upper Jingjiang reach＇s thalweg profile is incised obviously, but in the widening and multi-branched river reach, the problem that the navigable water depth is inadequate is outstanding. At the same time, in the Lower Jingjiang reach which scours and silts alternately, the transition section of the deep-channels in long straight/slightly curving reaches moves down, and the flow at the entrance of bends is much scattered, leading that waterway is unsteady. On that basis, combining with the numerical model forecast, in five to ten years after the TGP＇s impoundment, the reach from Taipingkou to Ouchikou would scour intensively, channel at the middle and lower water level in the widening and multi-branched river reaches would be wider and shallower, which would make the navigation condition worse, moreover the second branch would scour influencing the main branch＇s navigation condition. Meanwhile, the reach downstream from Ouchikou would be the initial stage of scouring, whether the shallow is unnavigable is mostly related to the incoming water＇s recession course, and a certain development of bends would make waterway vary. In fifteen to twenty years after the TGP＇s impoundment, bed scouring in the reach upstream from Ouchikou would finish basically and the Upper JingJiang＇s plane-form would be trending to stability. However, bed scouring in the reach downstream from Ouchikou would be intensive, the shallow transition area would be degraded leading to the navigable water depth increasing, and local cut-off of bends may occur, which is very disadvantageous to navigation.

关 键 词：荆江河段 三峡水库 河床演变 冲刷发展 航道变化 

分 类 号：TV147[水利工程—水力学及河流动力学]