中文摘要：

通过实测水文资料分析,提出了长江重庆九龙坡河段的冲淤判定因子U3/h,U3/h=0.24m2/s3可作为九龙坡河段冲淤判定的临界值,即当九龙坡河段U3/h〉0.24 m2/s3,该河段将发生冲刷,反之淤积。利用三维水动力数学模型,计算了不同坝前水位、嘉陵江汇流比和上游来流条件下的九龙坡河段U3/h值,分析了三峡水库蓄水后九龙坡河段汛后的走沙规律。

英文摘要：

Based on the measured data, it is showed that U3/h can be used as an indicator for determining the scouring or depositing state in the Chongqing Jiulongpo reach, and U3/h = 0.24m2/s3 is the critical value when sediment will be flushed. U3/h in Jiulongpo reach is calculated by a 3D flow numerical model when no measured data are available, which is used to study sedimentation in the Chongqing Jiulongpo reach.