摘要
依据实测水沙资料,运用比较分析法,系统分析了长江三峡水库蓄水运用对洞庭湖水沙特性的影响。结果表明:(1)荆江三口分流分沙比由18.5%,21.4%分别减少至11.7%,13.6%,导致三口占入湖总径流量、总输沙量比重,依次由41.5%,82.9%减少至21.6%,58.5%;(2)多年平均入湖水沙量分别减少了531×108 m3,4 715×104 t,湖盆泥沙淤积率由70.4%减少至39.5%,递减幅度为30.9%;(3)西、南、东3洞庭湖多年平均水位变幅分别降低了1.23,1.45,1.88m;(4)湖盆冲刷量大于淤积量,淤积泥沙颗粒趋于细化,西洞庭湖区与东南洞庭湖区的泥沙输出比均呈同步增大趋势。这些水沙特性的变化,对于延长洞庭湖寿命、减轻湖区洪涝灾害风险具有重大意义,同时也会给湖区造成一系列的生态环境问题。
According to the measured water and sediment data,using comparative analysis,the paper analyzed systematically the effects of store water application of the Three-Gorges reservoir on Yangtze river on water and sediment characteristics in the Dongting lake.The results indicated that：（1）The ratios of split-flow and sediment diversion at the three outfalls of Jingjiang river reduced separately from 18.5%,21.4% to 11.7% and 13.6%,which resulted in that the proportions of runoff and sediment discharge via the three outfalls into Dongting lake compared total runoff and total sediment discharge reduced respectively from 41.5%,82.9% to 21.6%,58.5%;（2）Average annual water and sediment volume into the Dongting lake decreased respectively 531×108 m3,4 715×104 t,sediment deposition rate in the lake basin reduced from 70.4% to 39.5% with a decreased range of 30.9%;（3）Average annual water level amplitude in the west,south and east of the Dongting lake decreased respectively 1.23 m,1.45 m and 1.88 m;（4）Sluicing capacity was greater than sediment deposition in the lake basin,deposited sand grain trends to thinning,sediment output ratios in the west and southeast of the Dongting lake present all synchronous increasing trend.The variations of water and sediment characteristics were of great significance towards prolonging the lifetime of the Dongting lake and easing the flood dangers as well as they brought about a series of eco-environment problems in the lake area.
出处
《水土保持学报》
CSCD
北大核心
2011年第3期215-219,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金(41071067)
湖南省重点学科自然地理学建设项目
关键词
三峡水库
蓄水
水沙特性
洞庭湖
the Three-Gorges reservoir
store water
water and sediment characteristics
the Dongting lake
