大型水库对其下游河流径流年际变化及年内分配的影响

Impact of Large Reservoir on Downstream Annual Runoff Variation and Distribution

基于鄂毕河干流科尔帕舍沃站及其支流额尔齐斯河上的鄂木斯克站逐月流量资料,采用启发式分割算法分析了新西伯利亚水电站对鄂毕河、布赫塔尔马水电站对额尔齐斯河下游流量序列的影响,找出序列的突变点,以此为分界点分别采用累积频率法和方差分析法分析了突变点前后流量序列的年际变化情况,并根据年内不均匀系数和集中度分析了突变点前后两站的年内分配变化情况。结果表明,鄂木斯克站流量序列在1960年发生突变,突变点前流量变幅较大,突变点后变幅明显减小,年内分配不均匀系数和集中度在突变点后显著减小;科尔帕舍沃站流量序列在1962年发生突变,突变点前后流量变幅无显著差异,年内分配不均匀系数和集中度在突变点后同样显著减小。可见在大型水库的运行调节下鄂毕河流域流量序列的年际和年内分配情况均受到了一定的影响。

Based on the monthly data of Kolpashevo station at Ob River and Omsk station at Irtysh River, it is meri- torious for studying the impact of Novosibirsk Hydropower Station and Bykhtarmo Hydropower Station on the runoff re gimes of the downstream. The heuristic segmentation algorithm is used to detect the catastrophe point and take it as the demarcation point. Using variance analysis and cumulative frequency curve, the characteristics of inter-annual runoff vari ation are analyzed. And then the annual runoff distribution is analyzed based on the uniformity coefficient and concentra- tion ratio. The results indicate that abrupt change happened in 1960 at Omsk, and in 1962 at Kolpashevo. At Omsk sta- tion, the amplitude of variation before the catastrophe point is larger than that after the catastrophe point. While at Kol- pashevo station, there is no observable change of the amplitude of annual runoff variation. The coefficients of variation and concentration degree of the two stations decrease significantly after the catastrophe point. So, it proves that the oper- ation of large reservoir on Ob River has influence on the annual runoff and its distribution.