三峡水库运行后库区航道条件变化及趋势

三峡工程蓄水运行以来,库区水位抬高,航道尺度大幅提高,航宽普遍在200m以上,峡谷河段受岸壁约束,增幅也达40～100m左右,航深4m以上,弯曲半径除局部河段外均大于1000m.分析表明:蓄水后常年库区枯水期碍航滩险消除,洪水期流量在20000m3/s以下时,基本无不良流态出现,水流平缓;流量在20000m3/s以上时,水流亦有较大减缓,变动回水区流速有所减缓.加之已实施的三峡工程施工期变动回水区航道整治工程,使常年库区及变动回水区航行条件得到较大改善,但遇洪水陡涨过程,峡谷河段仍会呈现不良流态.

Changes and trends of waterway in reservoir area after operation of Three Gorges Reservoir

Since the impounding of Three Gorges Reservoir,the channel scale of reservoir area has been substantially increased.The widths of the whole waterway are generally more than 200 m.The gorge waterway is restricted by quay;its channel width is increased by 40 to 100 m;the navigation depth is over 4 m.The bending radius,besides that of some sections,is greater than 1 000 m.Analyses show that the flow rate in fluctuating backwater area has been slowed down.In addition to the effect of waterway regulation project during the Three Gorges Project,the navigation conditions have been greatly improved.However,the flow in gorge waterway will still be unstable for navigation during the uprising process of flood peak.