摘要
三峡工程作为全球最大的综合性水利枢纽工程,其运行对坝下游的来水来沙条件、河道形态、河道比降及河床糙率等均产生了一定影响,进而引起同流量下洪水、中水、枯水位的适应性调整。为此,以长江中游宜昌至螺山站河段为例,采用多项式拟合法,探究了长江中下游同流量下水位变化特征。结果表明,三峡水库运行后,同流量中水、枯水位为下降趋势,同流量洪水位为上升态势,且存在一个临界流量,等于该流量时,同流量水位不发生变化,因此同流量对应的水位存在上升、下降转换的"临界转换流量"。宜昌站的临界转换流量的上下限为35 200~46 500m3/s,枝城站为35 600~46 400m3/s;受三口分流关系调整的影响,沙市站和监利站的临界转换流量上下限较低,分别为30 000~31 600、30 000~31 000m3/s;受洞庭湖入汇的影响,螺山站临界转换流量上下限值较高,为30 000~45 800m3/s。
As the largest comprehensive water control project in the world,the operation of the Three Gorges Project has a certain impact on the conditions of incoming water and sediment,channel morphology,river gradient and riverbed roughness at the downstream of the dam,thus causing adaptive adjustment of flood,medium and low water levels under the same discharge.In this paper,Yichang-Luoshan section of the middle reaches of the Yangtze River is taken as the study area to explore the variation characteristics of water level for the middle and lower reaches of the Yangtze River with the same discharge.The results show that after the operation of the Three Gorges Reservoir,the middle and low water levels of the same discharge tend to decline,while the flood levels of the same flow are rising;There is a critical flow,when equals to the flow,the water level of the same flow does not change;Therefore,the water level corresponding to the same flow has the "critical conversion flow" of rising and falling.The upper and lower limits of critical conversion flow of Yichang station are 35 200-46 500 m3/s,and those of Zhicheng station are 35 600-46 400 m3/s;Affected by the adjustment of diversion relationship of three outlets,the upper and lower limits of critical conversion flow of Shashi station and Jianli station are 30 000-31 600 m3/s and 30 000-31 000 m3/s,respectively;Affected by the inflow of Dongting Lake,Luoshan station has a higher limit of critical conversion flow with 30 000-45 800 m3/s.
作者
王超
李浩
柴元方
WANG Chao;LI Hao;CHAI Yuan-fang(Water Design Group Co.,Ltd.,Jinan 250000,China;China Institute of China Resources and Hydropower Research,Beijing 100038.China;State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)
出处
《水电能源科学》
北大核心
2021年第9期33-36,共4页
Water Resources and Power
关键词
三峡工程
长江中下游
同流量
水位
临界转换流量
Three Gorges project
the middle and lower reaches of the Yangtze River
the same discharge
water level
critical flow
