三峡水库蓄水期长江中游湖泊调蓄能力变化

长江中游通江湖泊的调蓄能力与整个区域的水安全密切相关。在对洞庭湖、鄱阳湖(下称“两湖”)调蓄机理探讨的基础上,揭示了两湖泊调蓄的临界状态及临界条件,分析了三峡水库蓄水期两湖泊调蓄能力的变化。研究结果表明:洞庭湖与鄱阳湖具有相同的调蓄机理,其调蓄能力变化受入湖流量和长江干流顶托的双重影响,湖泊调蓄过程表现为入湖与出湖水量的动态调整,湖泊调蓄量不断向0趋近。三峡水库运用后,两湖泊9—10月份调蓄能力下降明显,与2003—2007年相比,2008—2014年两湖汛后调蓄水量的减小更大。

Adjustment of Regulation and Storage Capacity of Lakes in the Middle Yangtze River Basin During Impoundment of Three Gorges Reservoir

The regulation and storage capacity of lakes in the middle Yangtze River basin is closely related with wa-ter security of the whole region. In this paper,the critical state and critical storage conditions of Dongting Lake and Poyang Lake,two typical largest lakes in the middle Yangtze River, are revealed by analyzing the mechanism of regulation and storage. Moreover,the adjustments of regulation and storage of the two lakes before and after the op-eration of Three Gorges Reservoir are quantified. Results demonstrate that the rules of regulation and storage of the two lakes are alike:storage capacity is affected by both the inflow of the lake and the blocking of the mainstream Yangtze River,which indicates that storage adjustment can be reflected by the dynamic changes of incoming flow and discharge,with regulation amount approaching zero constantly. After the operation of the Three Gorges Reser-voir,storage capacity reduced apparently from every September to October; the reduction after flood season of 2008-2014 was more intense than that of 2003-2007.