嫩江流域中下游径流量变化的时空特征

Spatial and Temporal Characteristics of Runoff in the Middle and Lower Reaches of the Nenjiang River Basin

为分析嫩江流域中下游径流量变化的时空特征,以1955~2005年嫩江中下游同盟、江桥、大赉站径流和降水为依据,应用Morlet小波分析法、Mann-Kendall检验、Sen趋势度估计、改进累积曲线等方法研究了嫩江中下游径流在年、季节尺度上的变化特征及周期性规律,并采用多元线性回归法、双累积曲线分析了径流对人类活动的响应规律。结果表明,嫩江中下游径流具有5、11、26年主周期,其中26年为第一主周期;嫩江中下游径流的年内分布规律基本一致,径流量最大峰值均集中于7月份;下游河川径流的波动性比中游大,1955~2005年中下游径流呈下降趋势,其下降趋势由中游到下游越来越显著;嫩江流域径流突变点发生于1979年;降水对径流无显著影响,径流减少趋势主要受人类活动的影响,且下游受人类活动的影响更大。

For analysis of the spatial and temporal characteristics of runoff in the middle and lower reaches of the Nenjiang River Basin,based on the runoff and precipitation data of Tongmeng,Jiangqiao and Dalai Hydrologic Stations in the middle and lower reaches of the Nenjiang River Basin during 1955-2005,the variation characteristics（in annual and seasonal）and periodicity of runoff in the middle and lower reaches of the Nenjiang River Basin were studied by using Morlet wavelet analysis,Mann-Kendall test,Sen-slope estimation,and improved cumulative curve method.And then the influence of runoff on the human activities were analyzed using the methods of multivariate linear regression and double cumulative curves.The results show that the runoff in the middle and lower reaches of the Nenjiang River Basin have a 5-year,11-year,and 26-year period,of which 26-year are the first main cycle;The distribution of runoff in the middle and lower reaches of the Nenjiang River Basin during the year was basically the same,and the maximum peak of runoff was concentrated in July;The runoff volatility in the lower reaches is greater than that in the middle reaches;During the period of1955-2005,runoff in the middle and lower reaches of the Nenjiang River Basin showed a downward trend,and its downward trend became more and more significant from the middle reaches to the lower reaches.A mutation in the annual runoff sequence occurred in 1979;Precipitation had no significant impact on runoff.The tendency of runoff reduction was mainly affected by the human activities,and runoff in the lower reaches was more affected by human activities.