黄河上游青铜峡水利枢纽对河川基流的影响

以黄河上游下河沿、青铜峡和石嘴山3个水文站1951—2000年径流量为基础背景资料，采用Lyne-Holick滤波法研究水利枢纽工程对河川基流量的影响。结果表明:(a)建坝前，3站基流量总体上相差不大，介于184~214亿m³之间；而建坝后青铜峡水文站基流量均呈明显减少的变化趋势，基流量为111~187亿m³，基流衰减量可达24%。(b)M-K非参数检验结果显示，青铜峡站基流量减少幅度最为明显，且突变点出现在1962—1964年青铜峡大坝建设时期。(c)在不同水平年条件下，建坝后，青铜峡基流指数减少幅度最大，其中丰水年中下降幅度达13%，而平水年下降幅度可达20%，表明水利工程对河川基流产生了一定的影响。

Effect of Qingtongxia hydraulic project in upstream of Yellow River on river baseflow

This study mainly analyzed the effect of hydraulic project on baseflow by the Lyne-Holick filter method, based on the runoff data that was monitored in three hydrological stations, Xiaheyan, Qingtongxia, and Shizuishan, from 1951 to 2000. Results show that baseflows of three hydrological stations were generally similar before the construction of Qingtongxia hydraulic project, all about(184-214)×10⁸m³. Moreover, baseflow data was decreased to(111-187)×10⁸m³ since construction of the project, which indicated that the decrease ratio was nearly 24%. Results by the Mann-Kendall method also shows that, the decrease of baseflow reached its maximum value at the Qingtongxia hydrological station, and the point of abrupt change was observed between 1962 and 1964, which was coincident with the construction of Qingtongxia project. The baseflow index(BFI)of Qingtongxia hydraulic station showed an obvious downtrend in wet years with about 13% and the decrease ratio of BFI was approximately 20% in ordinary years, which provide a valid evidence that the hydraulic projects have strong influence on baseflow.