鄱阳湖流域气候变化和人类活动对入湖水沙的影响

近些年鄱阳湖湖区季节性干枯问题频繁出现,有必要对鄱阳湖入湖水沙变化进行进一步研究。利用鄱阳湖流域"五河"基本水文站1961～2016年实测的水沙及流域降雨量资料,通过线性趋势、双累积曲线、经验统计法和统计系列对比法研究鄱阳湖入湖水沙演变过程及影响因素。结果表明:鄱阳湖流域降雨量、侵蚀性降雨量、降雨侵蚀力年际变化均呈不显著的上升趋势(P0.05)。入湖径流量年际变化趋势不显著,而入湖输沙量呈极显著的下降趋势(P0.01),且存在1985年和2000年两个突变点。影响入湖径流量和输沙量的关键降雨指标为年降雨量和降雨侵蚀力。以1961～1984年为基准期,1985～1999年经验统计法和系列对比法计算的水利水保工程减沙效应分别为41.8%和33.4%,在2000～2016年分别为70.6%和66.8%,水库拦沙是入湖输沙量减少的主要原因。

Effects of climate variation and human activities on runoff and sediment into Poyang Lake

This paper studied the evolution process and influence factors of streamflow and sediment into Poyang Lake using linear trend method, double mass curve analysis, empirical statistics method and statistical series comparison method. In the analysis, the measured data of flow and sediment and rainfall from 1961~2016 of several hydrological stations in Poyang Lake were adopted. The results show that the annual rainfall, erosive rainfall and interannual variation of rainfall erosivity all have an insignificant upward trends(P>0.05). The interannual variation of runoff into the lake is not significant, the sediment into the lake has an significant downward trend(P<0.01) with two abrupt change points in 1985 and 2000. The key precipitation indexes that affect runoff and sediment into the lake are annual rainfall and rainfall erosivity. The sediment reduction effects of water conservancy projects calculated by empirical statistics method and statistical series comparison method are 33.4% and 41.8% from 1985 to 1999, 70.6% and 66.8% from 2000 to 2016 compared with 1961~1984 as a referenced period.