中文摘要：

为更好地开展南水北调中线工程对汉江中下游水华生态环境问题的量化研究，分析了调水工程对汉江中下游水文情势的影响。基于仙桃断面的流量数据，计算分析了调水145亿m^3后有、无引江济汉工程两种方案下的流量特征值的变化，并应用分形理论分析了调水前后多年月平均径流过程线的形态特征。结果表明：调水工程对汉江中下游的水文情势有明显影响，主要表现为：径流年内分配趋于均匀化，径流年内集中度变小，径流年内相对变化幅度变小．径流过程线峰谷差变小，引江济汉工程使这些变化更显著：各种历时（年、枯期、汛期）平均流量均变小、旬平均流量极小值变小，引江济汉工程对这些变化起补偿作用。由于汉江水华的暴发期集中在枯水期，由调水工程引起的枯期流量减小以及旬流量极小值变小必然对汉江水华的爆发起到促进作用。

英文摘要：

In order to evaluate the influence of the middle route of the south-to-north water diversion project （MR-SNWDP） on water bloom in the middle and lower reaches of the Hanjiang River, the effects on the hydrological regime were analyzed. Based on the flow data of Xiantao Section, both of the fractal feature of flow curve and the variations of hydrological feature values （after the 145×108m^3 scheme of MR-SNWDP has been implemented） were calculated, considering if the diversion work from Yangtze River to Hanjiang River （DWYRHR） is built. The results indicate that the hydrological regime in the middle and lower reaches of the Hanjiang River will be obviously changed, mainly in the following ways： The annual runoff distribution will become more uniform, the annual runoff concentration will become lower, relative variation rate will become smaller, which will become more visible under the effects of the DWYRHR; the average flow of different period （year, flood season, dry season ） will become smaller, and the minimum flow of ten days will become smaller too, which will be mitigated under the effects of the DWYRHR. Since the outbreak of water bloom in the Hanjiang River concentrates in dry seasons, the decrease of average flow during dry season and the minimum flow of ten days surely will accelerate the outbreak of water bloom in the Hanjiang River.