中文摘要：

通过在三峡水系中重庆主城段的长江与嘉陵江现场布点、采样和分析自然水体中的藻类,在实验室内分别模拟氮磷比、光照和流速对嘉陵江水体中藻类生长的影响,发现在不同TN/TP和光照强度的静水环境中蓝藻和绿藻生长迅速,硅藻消亡很快,其它藻类变化不大,总藻细胞密度最大可达107个/L以上;而在0.03 m/s左右的缓流下总藻细胞增长最明显,但密度也只能达到106个/L,硅藻比例提高,当流速进一步加快,蓝藻和绿藻比例降低.显然,优势藻类随水文情势发生演替.总藻密度分别与TN/TP、流速拟合的可决系数R2均在0.93以上,与光照强度的拟合效果次之.自然状态下两江的现场水样分析还表明：嘉陵江总藻密度大于长江,硅藻占绝对优势,其次为绿藻和蓝藻,与实验室测试结果相符.

英文摘要：

Through sampling and analyzing algae species in natural water-body of the Yangtze river and the Jialing river located at Chongqing urban section along the Three-Gorges valley, and combining with monitoring on the influencing parameters to algae growth, such as TN/TP, light intensities and current velocities by experimental simulation, the effect on the algae propagation behavior has been studied systemically. The results show that under static hydrological condition with various TN/TP and light intensities the Chlorophyta and Cyanophyta would grow rapidly while the Bacillariophyta disappear quickly, and other algae species had little change, and the total algal cell density could exceed 10^7 cells/L. However, even if under lower current velocity as about 0.03 m/s, the total algae cell density would increase at most obviously while its density could only reach 10^5 cells/L, and the proportion of Bacillariophyta would increase with the increase of current velocity, the proportion of Chlorophyta and Cyanophyta begin decrease at same time. Apparently, evolution of the dominant algae species would take place according to the change of hydrological condition. The density of total algae is primal regressed to TN/TP and current velocities with coefficients of determination （ R^2 ） are all over 0.93 while it has lower regression coefficient with the light intensities. The samples analysis of the above two rivers under natural state also demonstrates that total algae density in the Jialing river is higher than that in the Yangtze river, and the Bacillariophyta has the absolute domination, and then are Cyanophyta and Chlorophyta, which fit in with the experimental results in our laboratory.