On the basis of hydrologic data at upstream and downstream stations of Three Gorges Reservoir(TGR) before and after the impoundment, significance test was performed on the trend of long-term flow variation observed at Cuntan station, Wulong station, and Yichang station by TFPW-MK method. The impact of TGR impoundment on runoff process was also comparatively analyzed. Results revealed that no evident impact on the runoff process was found, while the yearly runoff process was somehow influenced. The discharge volume from December to next June was larger than natural runoff, while was reduced remarkably from September to November with a maximum decrease of 12 015 mVs in 2009. Having been optimized by the impoundment scheme at the end of flood season, the maximum decrease of discharge volume fell to 7 923 mVs.%依据三峡水库蓄水前后上下游水文站的观测资料,采用TFPW - MK方法对寸滩站、武隆站、宜昌站观测流量的长期变化趋势进行了显著性检验,并对三峡水库蓄水运行以来水库对径流过程的影响做了对比分析.结果表明三峡水库运行对径流总量无明显影响,但对径流的年内过程有一定影响:12 -6月水库下泄流量大于天然径流量,而9-11月蓄水期则存在明显的减泄现象,2009年最大减泄流量12 015 m3/s.经优化调整后的三峡水库汛末蓄水方案,对此减泄过程有一定缓解,2010年最大减泄流量7 923 m3/s.
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