%0 Journal Article %T 三峡小江回水区透明度季节变化及其影响因子分析 %T Seasonal variation of transparency and its regulating factors in the Xiaojiang backwater area,Three Gorges Reservoir %A 张呈 %A 郭劲松 %A 李哲 %A 蒲清平 %A 方芳 %A 龙曼 %A 高旭 %A ZHANG,Cheng %A GUO,Jinsong %A LI,Zhe %A PU,Qingping %A FANG,Fang %A LONG,Man %A GAO,Xu %J 湖泊科学 %J Journal of Lake Sciences %@ 1003-5427 %V 22 %N 2 %D 2010 %P 189-194 %K 三峡水库;小江回水区;透明度;无机悬浮颗粒;叶绿素a %K Three Gorges Reservoir;Xiaojiang backwater area;transparency;inorganic particulate;chlorophyll-a %X 三峡成库后其季节调蓄过程使该水域湖沼学特征具有独特性.根据三峡小江流域回水区段为期2年的定位跟踪观测,对透明度(SD)和主要环境指标的相互关系进行分析研究.研究期间,小江回水区透明度均值为170±7cm,各采样点透明度差异不明显且季节变化过程-致,自春末夏初开始降至最低水平,夏季汛期相对稳定,夏末入秋持续升高,冬季维持在较高状态,入春后下降.对透明度和主要环境指标的相关性分析发现,无机悬浮颗粒(PIM)是影响透明度的主要指标.透明度同PIM、Chl.a多元回归模型为:SD=(-89.389±8.101)·lg(PIM)+(-84.008±8.624)·lg(Chl.a)+(264.132±8.232).汛期低水位状态下(145-150m)小江回水区水动力条件趋于天然河道,河道输沙量增加使无机悬浮颗粒含量远高于藻类生物量而成为影响透明度的主要环境指标.在中水位(150-156m)和高水位(156m以上),虽然藻类进入非生长季节,但水位抬升和水体滞留时间的延长促使悬浮颗粒物大量沉淀,悬浮生长于表层水体的藻类成为影响透明度的主要环境指标,生物作用对透明度的影响明显. %X Limnological characteristic of the Three Gorges Reservoir(TGR) is unique due to its seasonal operation of the ThreeGorges Dam. A 2-year monitoring along 5 sampling sites was conducted in the backwater areas of Xiaojiang River(XBA) in theTGR.Mean value of transparency(SD) in the XBA was 170 17em during the study. No significant difference was detected amongthe sampling sites through the seasons. It was found that SD was low during the flood season, increased in the late summer, andcontinuously increased to winter during the high water level operation stage. Spearman rank correlation analysis on SD and environ-mental variables showed that particulate inorganic matter(PIM) and chlorophyll-a(Chl.a) were the factors that impacted SD inthe XBA. The regression model of SD and log transformed PIM, Chl. a was SD=(-89.389±8. 101).lg(PIM )+(-84. 008±8. 624 ).Lg(Chl.a)+(264.132±8.232).It showed that under the low water level operation stage(145-150m),hydrodynamiccondition in the XBA was close to that in natural rivers with high concentration levels of PIM that much more significantly impact onthe variation of SD than nn Chl. a.In operation stages of intermediate water level(150-156m)and high water level(above156m),with the sedimentation of large amount of PIM, the suspended phytoplankton became the principle factor that influence thevariation of SD instead of PIM, even if the investigated period was not the growing season of phytoplankton. %R 10.18307/2010.0206 %U http://www.jlakes.org/ch/reader/view_abstract.aspx %1 JIS Version 3.0.0