中文摘要：

针对近期荆江段河槽形态的显著调整,定量研究了三峡工程运用对其造成的影响。计算了2002—2013年该河段断面及河段尺度的平滩河槽形态参数,并建立这些参数与宜昌站汛期水流冲刷强度的经验关系。还原了在无三峡工程时宜昌站的水沙数据,计算了相应的河槽形态参数,分析了有、无三峡工程时荆江段河槽形态调整的差异。计算结果表明：三峡工程运用后近期荆江段平均河床比降略有调平,河段平滩水深逐年增加,但平滩河宽变化较小,使得河相系数减少6.7%~10.3%;无三峡工程时平滩河槽形态调整较缓,河段平滩水深及面积的增幅分别仅占有三峡工程时的16%和18%。故三峡工程运用没有改变近期荆江段河槽形态趋于窄深的调整趋势,但一定程度上加快了调整过程。

英文摘要：

In order to investigate the impacts of the Three Gorges Projects （TGP） operation on the recent cnannet adjustment in the Jingjiang Reach, bankfull channel dimensions at both section- and reach-scale were calculated annually from 2002 to 2013, with empirical relationships being proposed between these dimensions and the previous 5- year average fluvial erosion intensity during flood seasons at the Yichang hydrometric station. Hydrological data at this station were then estimated under the scenario without the TGP, and used to evaluate the corresponding bankfull di- mensions. Differences were analyzed between the variations in bankfull dimensions under these two scenarios. The re- suits indicate ： （1） after the TGP operation, the bankfull widths and depths at four typical sections increased gradually, with a remarkable increase in the width; （2） the longitudinal channel slopes tended to flatten in the Jingjiang Reach, with an appreciable increase in the reach-scale bankfull depth and a slight change in the reach-scale bankfull width, which caused the geomorphic coefficient decreasing by 6.7%--10.3% ; （3） Changes in bankfull channel geometry were slighter under the scenario without the TGP, with the increase ranges in the reach-scale depth and area account- ing respectively for 16% and 18% of those under the scenario with the TGP. Thus, the TGP operation didn＇t alter the trend of the recent adjustment in bankfull channel geometry of the Jingjiang Reach, which tended to have a narrower and deeper channel geometry, but accelerated the adjustment process.