鄱阳湖出入湖径流量变化过程及与长江相互作用关系

Runoff variation of inflow-outflow from the Poyang Lake and interactions with the Yangtze River

根据1950-2012出入湖径流量和1950-2010湖内各站水位,运用M-K和回归分析等方法,系统分析鄱阳湖出入湖径流量和湖内水位的变化过程,探讨鄱阳湖与长江的相互作用关系。结果表明:1)鄱阳湖出入湖径流量的年际分布比较均匀,其变化主要受流域降雨的影响;2)出入湖径流量呈无显著增加的趋势变化,发生突变的年份为1991年;3)“五河”入湖径流量是湖内水位变化的主要影响因素,对鄱阳湖与长江相互作用关系的强弱变化起着决定性作用。从年代际变化来看,长江作用较强的时期为1960s和1980s,鄱阳湖作用较强的时期为1970s和1990s;从季节变化来看,4-6月和12月至次年3月主要为鄱阳湖作用期,7-11月主要为长江作用期;4)1950-2010共有47 a发生过江水倒灌入湖现象,主要集中在长江作用较强的两个时期的7-9月,这是由于从7月开始长江进入主汛期,流量增大,水位抬升,高流量和高水位容易对鄱阳湖产生倒灌作用。

By using methods of the M-K non-parametric test and the regression analysis,variations of inflow-outflow runoff from the Poyang Lake in the period of 1950-2012 and water level in the Poyang Lake in the period of 1950-2010 have been analyzed,and then interactions with the Yangtze River flow and have been discussed.Results show that inflow-outflow runoff from the Poyang Lake is distributed evenly in the interannual time scale,and the interannual variations are mainly influenced by precipitation.There is no significant increase trend in the inflow and outflow runoff from the Poyang Lake,and both of the mutation is in 1991.Runoff from the five major tributaries is the major factor for water level variation of the Poyang Lake,which to a large extent determines interactions of the Poyang Lake and the Yangtze River.In the decadal timescale,times of the strong Yangtze River effect are 1960s and 1980s and the weak Yangtze River effect are 1970s and 1990s.In the seasonal timescale,periods from April to June and December to March of the next year are mainly the Poyang Lake action,and period from July to November is mainly the Yangtze River action.There are total 47 years that the Yangtze River flow invaded to the Poyang Lake during the period of 1950-2010,and mainly concentrated in July to September in two stages with strong Yangtze River effect.Because the Yangtze River entered the major flood season from July,which caused the increase of flow and the rising of water level,the high flow and the high water level of the Yangtze River are easy to cause intrusion to the Poyang Lake.