金沙江下游及三峡梯级径流均匀度及突变性分析

Study on runoff uniformity and mutation for the lower Jinsha reaches and the Three Gorges cascade

本文以1954-2008年屏山、寸滩和宜昌水文站径流资料为依据,用Gini系数研究了径流时空分布均匀度变化,用小波变化研究了径流突变。表明流域梯级上游水库的调蓄对下游水库径流分配均匀程度产生影响明显,但是,上游水库对下游水库径流量的影响程度取决于上游水库的调节性能,对于调节性能不高的水库,流域天然径流的丰枯变化大于水库的调蓄影响。结果对研究解决梯级水电站开发对河流的胁迫问题具有重要的现实意义。

Abstract： This paper describes an application of Gini coefficient and wavelet method to analysis of the runoff data series of the years 1954-2008 at three hydrological stations, Ping Shan, Cuntan and Yichang, focusing on spatial and temporal distributions of runoff and runoff mutation. The results show a significant impact on the runoff distribution uniformity of downstream reservoirs by the regulation of upstream reservoirs in the same cascade system. The intensity of this impact depends on the regulation performance, and the changes caused by natural wet-dry alternation will be dominant in the case of low regulation level. These results would be practically significant to the development of cascade hydropower stations.