三峡出库流量与鄱阳湖水位定量响应关系研究

Quantitative Response Relationship between Three Gorges Reservoir Outflow and Water Levels in Poyang Lake

摘要: 构建三峡水库调度过程与鄱阳湖水位之间的定量响应关系，对理解长江中下游江湖水动力耦合机制、优化水资源调控及生态水位管理具有重要意义。基于三峡出库流量与鄱阳湖水位数据，本研究揭示了两者的关键响应特征。结果表明：1) 三峡出库流量与鄱阳湖水位在季节上高度一致，丰水期流量增加对应显著的水位攀升，存在约3~7天的响应滞后；2) 二次多项式拟合显示关系显著非线性(R² = 0.586)，10,000~20,000 m³/s区间水位对流量敏感性最高，超过约20,000 m³/s后增水效率出现递减；3) 断点回归识别到关键转折点约为22,500 m³/s，显示湖体从以蓄水为主向以泄洪为主的水动力机制转变。本研究分析了三峡水库调度对鄱阳湖水位的结构性影响，研究成果对三峡水库优化调度、鄱阳湖生态水位管理及洪水风险控制提供了科学参考。

Abstract: Quantifying the response of Poyang Lake water level to the outflow discharge from the Three Gorges Reservoir (TGR) is essential for understanding river-lake hydrodynamic interactions in the middle-lower Yangtze River, optimizing reservoir operation, and improving ecological water-level management. Based on TGR outflow and Poyang Lake water-level data, this study identifies their key response characteristics. Results show that: 1) TGR outflow and lake water level share strong seasonal synchronicity, with a 3~7 day response lag; 2) The discharge-water level relationship is distinctly nonlinear (R² = 0.586), with the highest sensitivity occurring in the 10,000~20,000 m³/s range. Beyond 20,000 m³/s, the efficiency of water level increase diminishes; 3) A critical breakpoint of approximately 22,500 m³/s indicates a hydrodynamic shift from storage-dominated to spill-dominated conditions. These results highlight the structural impact of TGR regulation on Poyang Lake water levels and provide scientific support for reservoir operation, ecological water level management, and flood-risk mitigation.