CAJ | 학술논문

以三峡大坝汛期洪水调度为契机,于2013年7月在香溪河开展原位监测,研究了洪水调度对藻类群落结构的影响.结果显示：在洪水调度期间香溪河水位变动范围是145.63~148.36m,河流中上游平均流速变化幅度小于河口平均流速变化幅度,中上游与河口的平均流速存在显著差异(P<0.05).调度前香溪河的藻类优势类群为蓝藻与硅藻,蓝藻所占比例高于硅藻,调度结束后,中上游水域硅藻占优势,河口区域蓝藻所占比例升高.香溪河水环境特征与藻类群落结构在洪水调度期间发生了显著改变,Shannon-Weaver 指数趋于下降.研究结果表明：三峡大坝拦蓄洪水的过程显著改变了香溪河水环境条件,洪水顶托作用首先改变了支流的水文水动力学特征和水质状况,随后藻类群落快速变化响应了这种改变.洪水调度所营造的动态水位使得靠近大坝的支流生境受到强烈冲击和破坏,导致了藻类种类和生物量的变化；由此可见,水库的动态水位可改变支流的藻类群落结构,有助于抑制和延缓支流水华的发生.
이삼협대패신기홍수조도위계궤,우2013년7월재향계하개전원위감측,연구료홍수조도대조류군락결구적영향.결과현시：재홍수조도기간향계하수위변동범위시145.63~148.36m,하류중상유평균류속변화폭도소우하구평균류속변화폭도,중상유여하구적평균류속존재현저차이(P<0.05).조도전향계하적조류우세류군위람조여규조,람조소점비례고우규조,조도결속후,중상유수역규조점우세,하구구역람조소점비례승고.향계하수배경특정여조류군락결구재홍수조도기간발생료현저개변,Shannon-Weaver 지수추우하강.연구결과표명：삼협대패란축홍수적과정현저개변료향계하수배경조건,홍수정탁작용수선개변료지류적수문수동역학특정화수질상황,수후조류군락쾌속변화향응료저충개변.홍수조도소영조적동태수위사득고근대패적지류생경수도강렬충격화파배,도치료조류충류화생물량적변화；유차가견,수고적동태수위가개변지류적조류군락결구,유조우억제화연완지류수화적발생.
Flood control is an important function for Three Gorges Reservoir (TGR). In July 2013 there was 3 flood peaks in TGR and flood regulation was used to block the deluge and reduce the impact on the middle and lower reaches of the Yangtze River. Anin situ investigation was conducted to screen the effects of flood regulation on phytoplankton community structure in the Xiangxi River. During the course of flood regulation, the water level in Xiangxi River ranged from 145.63m to 148.36m, the change of the average velocity in the estuary was higher than that in the midstream. There was a significant difference in average velocity between the estuary and midstream (P<0.05). Before the flood regulation, the dominant algal taxa were cyanophyta and bacillariophyta, cyanophyta had a higher proportion in both sampling sites. During the flood regulation period, hydrodynamic characteristics and algal community structure were significantly changed, Shannon-Weaver index decreased. After the flood regulation, diatoms were dominant in the midstream, while the proportion of cyanophyta increased gradually in the estuary. The flood regulation changed the environmental conditions. Hydrological and hydrodynamic characteristics in backwater caused by flooding regulation has been changed markedly, which influenced water quality of tributaries; consequently, followed by rapid changes in phytoplankton community. Results indicated the fluctuation of water level caused by flood regulation destroyed the habitat of algae strongly, and then leads to the changes of community structure. It could be deduced that such flood regulation would be helpful to inhibit and delay the formation of algal bloom in the tributaries of Three Gorges Reservoir.