三峡水库蓄水前后洞庭湖区洲滩出露面积变化规律  

Variation law of exposed area of shoals in Dongting Lake before and after impoundment of Three Gorges Reservoir

作　　者：尹律 上官江 郭小虎[3] 渠庚[3] YIN Lyu;SHANGGUAN Jiang;GUO Xiaohu;QU Geng(China Three Gorges Corporation,Wuhan 430010,China;Changjiang Survey,Planning,Design and Research Co.,Ltd.,Wuhan 430010,China;Key Laboratory of River and Lake Management and Flood Control in the Middle and Lower Reaches of the Yangtze River of MWR,Changjiang River Scientific Research Institute,Wuhan 430010,China)

机构地区：[1]中国长江三峡集团有限公司,湖北武汉430010 [2]长江勘测规划设计研究有限责任公司,湖北武汉430010 [3]长江科学院水利部长江中下游河湖治理与防洪重点实验室,湖北武汉430010

出　　处：《水利水电快报》2024年第12期65-71,88,共8页Express Water Resources & Hydropower Information

基　　金：长江水科学研究联合基金(U2240224,U2240206);湖南省重大水利科技项目(XSKJ2022068-39)。

摘　　要：三峡水库蓄水后,下泄水沙过程改变,对洞庭湖出口处城陵矶水位造成一定的影响,城陵矶水位改变致使湖区洲滩出露面积发生较大变化,对湖区水资源利用、水环境生态等带来一定的影响。因此,利用1955~2022年实测资料分析三峡水库蓄水前后洞庭湖区洲滩出露面积变化规律。结果表明:三峡水库蓄水后洞庭湖区以微冲为主,洲滩出露面积的变化主要受城陵矶水位变化的影响;由于城陵矶水位与螺山站水位相关性好,干流河道地形变化引起枯水流量下的螺山站水位下降明显,洪水流量下的水位变化不明显;三峡水库下泄径流过程变化导致1月1日至4月20日螺山站平均流量增大,8月26日至11月15日螺山站平均流量减小;在干流河道地形变化与径流过程改变综合影响下,枯水期、消落期及汛期湖区洲滩出露面积变化不大,对湿地环境的影响不大;蓄水期洲滩出露面积则增大13.5%,流量减小是引起洲滩出露面积增大的主要因素,湖区洲滩出露面积增大引起苔草类和芦苇群落生物量不断向水深区域增加,这是汛后蓄水期湖区频繁出现“大草原”的根本原因。After the impoundment of the Three Gorges Reservoir,the downstream water and sediment discharge process had changed,which had a certain impact on the water level at Chenglingji,the outlet of Dongting Lake.The change in the water level at Chenglingji leads to significant changes in the exposed area of shoals in the lake area,which has a certain impact on the utilization of water resources and the ecological environment of the lake area.Therefore,using the measured data from 1955 to 2022,the variation law of the exposed area of shoals in the Dongting Lake area after the impoundment of the Three Gorges Reservoir was analyzed.The results showed that after the impoundment of the Three Gorges Reservoir,the Dongting Lake area was mainly slightly scoured.The change in the exposed area of shoals was mainly affected by the change in the water level at Chenglingji.Since the water level at Chenglingji had a good correlation with the water level at Luoshan Station,the terrain change of the main stream channel caused a significant drop in the water level at Luoshan Station under low water flow,while the water level change was not obvious under flood flow.The change in the runoff process discharged from the Three Gorges Reservoir leads to an increase in the average flow at Luoshan Station from January 1 to April 20 and a decrease in the average flow at Luoshan Station from August 26 to November 15.Under the comprehensive influence of the terrain change of the main stream channel and the change in the runoff process,the exposed area of shoals in the lake area would not change much in the dry season,draw down period,and flood season,and had a little impact on the wetland environment.During the impoundment period,the exposed area of shoals increased by 13.5%.The decrease in flow is the main factor causing the increase in the exposed area of shoals.The increase in the exposed area of shoals in the lake area causes the biomass of carex and reed communities to continuously increase in the deep water area,which is the fundamental reas

关 键 词：洲滩面积 洞庭湖 三峡水库 蓄水影响 

分 类 号：TV147[水利工程—水力学及河流动力学]