三峡梯级水库对长江中下游水文情势影响研究

以梯级水库下游宜昌水文站1882-2006年流量资料为研究对象，采用Mann-Kendall法对宜昌站流量变化进行了趋势性分析，并采用复Morlet小波周期性分析，在此分析基础上采用变动范围法（RVA）分析葛洲坝水库蓄水前后宜昌站水文情势变化，定量评价了水文情势改变程度，随后对三峡水库蓄水前后宜昌站水文情势变化进行了分析。结果表明，葛洲坝水库对水文情势改变程度为29%，影响程度相对较小，而三峡水库蓄水后，在较大程度上改变了河流水文情势，水文情势改变必将影响到长江中下游河流水生生物生态安全。

Effects of Three Gorges cascade reservoirs on river hydrological regimes of the middle and lower Yangtze River

Abstract: Based on the daily mean flow from 1882 to 2006 of Yichang hydrologic station downstream of the cascade reservoirs, the method of Mann-Kendall was applied to analyze river flow trend of Yichang hydrological station and the Morlet wavelet transformation was used to analyze the periodicity variation. On the basis of flow variation analysis, Range of variability approach (RVA) was applied to analyze the hydrologic regimes of Yichang hydrological station before and after Gezhouba reservoir impoundment and the overall degree of hydrological alteration was evaluated, then the hydrological regimes variation before and after Three Gorges reservoir impoundment was analyzed. The results showed that the overall degree of hydrological alteration due to Gezhouba reservoir impoundment is 29% and it was defined with low alternation, however, after Three Gorges reservoir impoundment the hydrological regimes were altered more seriously. The hydrological regimes alteration will influence the safety of river aquatic organisms in the middle and lower Yangtze River.