中文摘要：

为保护和恢复河流生态系统健康，本文通过河流不同流量形态的生态意义的分析，探讨了生态流量的内涵及其谱系结构，将生态流量谱系划分为极低流量、低流量、高脉冲流量、高流量、极高流量五种流量形态。以潮白河源区为研究区域，利用大阁水文站1956～2003年48年的实测日流量资料，对参照期（1956～1974年）和影响期（1975～2003年）的生态流量谱系特征进行分析，结果表明，影响期较参照期多年平均极低流量、低流量、高流量分别减少了31％、4％、9％，极高流量消失，高脉冲流量则增加了5％，若以参照期生态系统的状况为生态保护和恢复的目标，就生态流量而言，潮白河源区须通过合理的水量调控应重点增加极低流量的大小。

英文摘要：

To protect and rehabilitate health of riverine ecosystem in Chaobaihe River, this paper investigated the ecological implication of the stream_flow regime and proposed the concept of ecological flow. The spectrum of the ecological flow includes extreme low flow, low flow, high pulse, high flow and extreme high flow in consistent with those proposed by IHA （Indicators of Hydrologic Alteration）. For the case study in the headwaters of Chaobaihe River using daily streamflow data from 1956 to 2003 of Dage Hydrological Station, because of the significant changes of hydrologic cycle, the period from 1956 to 1974 was named reference period, while 1975 to 2003 was named as influenced period. The results showed that the ecological flow spectrum of the influenced period was quite different from that of reference period. The average value of extreme low flow, low flow, high pulse, high flow and extreme high flow are respectively 1.09, 2.43, 6.5, 14.95 and 25 m^3/s in reference stage, while the influenced period extreme low flow, low flow and high flow drop respectively by 31%, 4% and 9%, and the extreme high flow disappears but the high pulse was increased by 5%. From the point of view of ecological flow, if the ecological situation in reference period is acceptable for ecological restoration, it is important to increase the quantity of extreme low flow in the headwaters of Chaobaihe River.