三峡水库汛末蓄水对鄱阳湖水位的影响研究

The Impact of Three Gorges Reservoir Impoundment on Water Levels in Poyang Lake

三峡水库汛末蓄水改变了长江中下游的水文过程,对鄱阳湖水位存在潜在影响。采用多元线性回归模型建立鄱阳湖水位与汉口流量、5河(赣江、抚河、信江、饶河、修水)流量的函数关系,并假设该函数关系在三峡水库运行前后保持不变。通过三峡水库运行后引起的汉口流量改变值,得到鄱阳湖水位的变化量。拟定3种不同的蓄水方案,分析了鄱阳湖水位受三峡水库蓄水的影响大小及空间格局特征。结果表明:受蓄水影响,起蓄时间10月1日、9月15日和9月1日对应的星子站水位降低值分别为2.23、1.37和1.05 m,都昌站分别为2.10、1.29和0.99 m,康山站分别为1.38、0.91和0.68 m。水位影响随起蓄时间的提前而减弱,空间上呈北高南低的格局。从消除或减免三峡水库蓄水对鄱阳湖的影响角度,建议优化三峡水库汛末蓄水调度方式,并做好与鄱阳湖5河支流水库调度之间的协调。

The refill operation of Three Gorges Reservoir （TGR） at the end of flood season potentially alters the water level regimes in Poyang Lake by reducing Yangtze River flow discharge. The multiple linear regression model is established to estimate the water level of Poyang Lake with catchment inflow （Five Rivers, i.e. Ganjiang, Fuhe, Xinjiang, Raohe, Xiushui） and Yangtze River （Hankou） flow as explanatory variables. The functional relationship is assumed to remain unchanged before and after the operation of TGR. The water level changes of Poyang Lake then are obtained by Hankou flow changes due to refill operation of TGR. Three impoundment schemes are drawn up to analyze the impact of TGR refill operation on water levels in Poyang Lake and its spatial pattern. Results show that the water level reductions induced by TGR refill operation for Xingzi, Duehang and Kangshan Station are 2.23 m, 1.37 m and 1.05 m, 2.10 m, 1.29 m and 0.99 m, 1.38 m, 0.91 m and 0.68 m associated with impoundment start time of October 1, September 15 and September 1. It is suggested that the TGR refill operation scheme be optimized at the end of the flood season, and the coordination of reservoirs＂ operation in the catchment is achieved to eliminate or weaken the impact of TGR refill operation of Poyang Lake.