鄱阳湖流域降水量变化对水沙演变影响研究

利用鄱阳湖流域"五大"入湖河流控制水文站实测水沙资料,探讨了鄱阳湖流域1961—2006年水沙变化特征及其演变趋势,在此基础上应用线性回归分析方法揭示了鄱阳湖流域水沙演变过程对流域降水的响应。研究结果表明,1961—2006年鄱阳湖流域降水量和入湖径流量总体略呈上升趋势,降水日数呈下降趋势,表明降水强度增加、降水时间分布不均匀更加明显。鄱阳湖流域降水和径流基本符合幂函数关系。相关分析结果显示,鄱阳湖入湖泥沙总量和径流量、降水量、降水强度均具有很好的正相关关系,水体中的泥沙含量和径流系数具有很好的负相关性,说明流域降水量和降水强度均对流域产沙量和输沙量有促进作用;流域月降水量与月输沙量基本符合幂函数关系,进一步说明了流域产沙量是降水量和降水强度综合作用的结果。

Influence of Precipitation Variation to Silt-Discharge Evolution of Poyang Lake Catchment Basin

The paper investigated the characteristics of silt-discharge variation and its evolution trend of Poyang Lake catchment basin in 1961-2006 period by using the observed data of silt and discharge of hydrological control station of five major inflow rivers,and revealed the response of evolution process of silt-discharge to precipitation of the basin by using the method of linear regress analysis.The outcomes show that the precipitation and lake inflow of the basin in the period of 1961-2006 are in the trend of increase and precipitation days in the trend of decrease,showing the increase of precipitation intensity and uneven distribution of precipitation time is more obvious.The precipitation and runoff of the basin are basically in line with the relation of power function.The results of correlation analysis show that: there was good positive correlation between the total quantity of incoming sediment,runoff,precipitation and precipitation intensity,and good negative relativity between sediment concentration of water and runoff coefficient,showing the promoting effect of precipitation and precipitation intensity to the sediment production and sediment discharge of the basin.The monthly precipitation and monthly sediment discharge are basically in line with the relation of power function,further showing the sediment production is the result of integrated function of precipitation and precipitation intensity.