中文摘要：

采用统计资料分析与实践探讨相结合的方法,对利津水文站水沙数据进行一系列分析,并在此基础上探讨小浪底对水沙变化的影响机制。结果表明：小浪底调水调沙作用改变了水沙的年内分布,汛期始期提前至6月,结束期延长至11月,汛期与非汛期间的差异变小,水沙量年内分布趋于均匀,但总体上年水沙量较天然条件下分别偏少27.4%,72.1%;小浪底通过调节水沙配置,使水沙比和来沙系数趋于正常化和合理化（0.01t/m3,0.01kg.s/m6）,水沙搭配关系得到明显改善,对黄河三角洲（黄三角）河口沙嘴和海岸动态平衡的保持意义重大;小浪底使黄河三角洲全年保持一定的流量和3 000～4 000m3/s的洪峰量,有效遏制了断流的发生,并且使泥沙组成明显粗化。

英文摘要：

Using methods combining statistical data analysis with practice discussion,the flow/sediment data of Lijin hydrological station and the influencing mechanism of Xiaolangdi on flow/sediment variation were analyzed.The results show that： Flow/sediment regulation of Xiaolangdi changes the annual distribution,the beginning phase of flood season advancing to June and the ending phase extending to November,the difference between flood season and non-flood season are getting smaller,the annual distribution of flow/sediment are tending to uniform,but in general,the annual flow/sediment are less 27.4%,72.1%,when compared with that in natural conditions;by adjusting the flow/sediment allocation,the ratio of flow/sediment and incoming sediment coefficient tend to normalize and rationalize（0.01 t/m3,0.01 kg·s/m6）,and the flow/sediment combination is improved obviously,which is very significant for maintaining the dynamic balance of the estuary sand spit mouth and coastal in Yellow River Delta（YRD）;Xiaolangdi project makes the YRD maintain a certain flow and flood peak（3 000~4 000 m3/s） all the year-round,which restrains effectively the occurrence of flow-break,moreover,sediment composition remarkably coarsens.