中文摘要：

采用长江流域宜昌、寸滩和武隆站长系列水文资料，借助Mann—Kendall统计分析、dbN小波分析、径流集中度与集中期等方法对宜昌站几十年来径流量年际和年内变化，尤其是三峡工程运行对宜昌径流变化的影响进行了分析。结果表明：近60年来宜昌站径流汛期有显著减少趋势，枯季则有不明显增加趋势，年内分配比例也发生了变化，在2000年-2010年时段表现最明显；2000年后，宜昌站2月（径流量最小月）和10月（汛期末端）径流有突变现象，径流跳跃点（2006年）恰好与三峡水库二期蓄水时间一致。径流变化的时空分析结果证实，三峡工程运行加剧了长江上游径流汛期减少与枯季增加的趋势，使年内分配差异减小。枯季水库增泄发电使同期坝下游径流量增加，保证了中下游枯季基流量；汛末蓄水使同期坝下游长江径流量减少，可能使枯水年中下游提前进入枯水季节；这必将对长江中下游地区的水资源利用乃至生态环境产生深远影响。

英文摘要：

The notion of ＇maintain a healthy Yangtze River and promote harmonious man-water relationships＇ is being actively practiced in China. The Three Gorges Project （TGP） achieved remarkable flood control and avoids peak discharge. Especially, in the flood period of 2010 when peak flow was close to that of 1998, the TGP effectively controlled upper Yangtze River flooding and reduced the amount of flooding in Jingjiang reach and Dongting Lake. It is now necessary to change contemporary ideas on water management, and explore a reasonable way to reach a harmonious man-water relationship for the Yangtze River basin. Here, hydrological data in Yichang, Cuntan and Wulong gauging stations were collected and analysed using Mann-Kendall tendency and mutation inspection, dbN Wavelet Analysis, concentration rates and concentrated periods of runoff. Our results indicate a decreasing trend in the flood season and increasing trend for dry season Yichang runoff. Annual runoff distribution within a year also changed in the last 60 years and this phenomenon＇ s manifestation was most obvious in 2000-2010. There have mutations in February （minimum monthly runoff） and October （end of flood season） in Yichang runoff since 2000. The runoff sequence＇ s break point happened during the second phase of the Three Gorges Reservoir （TGR） in 2006. Runoff variation in time and space confirmed that the operation of the TGP aggravated the decline in the flood season and increase in dry season runoff upstream of the Changjiang River. When the reservoir draws off water for power generation this augments the quantity of main stream runoff after the Three Gorges Dam （TGD） in the dry season, easing the lack of water downstream. The impounding of water at the end of flood season by the TGR decreased TGD downstream runoff and means the mid-lower reaches of the Changjiang River enter the dry season earlier.