新安江流域降水、径流演变特征分析

Characteristics of Evolution of Precipitation and Runoff in Xin′ An River Basin

为了掌握新安江流域降水、径流的演变特征,采用Mann-Kendall检验法、Morlet小波分析法对新安江流域近57年的降水、径流数据的月、年际变化,年序列的突变和周期特征进行了统计和分析。结果表明:春夏季的4—7月是新安江流域降雨和径流最为集中的时段,新安江流域年降雨、径流的年际变化均呈明显增多的趋势,新安江流域年径流、降雨的突变异常时间基本吻合,两组序列的第1主周期均为17a,第2,3周期分别是7a,3a,目前正处于不同周期中的丰水年中。两组序列高度相关,且具有极其吻合的同步变化特征。可见新安江流域属于雨水补给型河流,降雨是影响该流域径流最主要的因子。新安江流域可利用径流和降雨两组序列建立了线性回归模型,其拟合和预报效果较好,在流域长期径流量预报业务中有一定的应用价值。

In order to grasp the evolution of precipitation and runoff in the Xin′an River Basin,Mann-Kendall test method and Morlet wavelet analysis method were used to analyze the monthly and inter-annual changes of precipitation and runoff data in the Xin′an River Basin in the past 57 years,and the mutations and the periodic characteristics of the annual series were measured and analyzed.The results show that it′s the most concentrated periods of rainfall and runoff in the Xin′an River Basin from April to July in spring and summer;the interannual variation of annual rainfall and runoff in Xin′an River Basin showed the increasing trend;the abnormal time of annual runoff and rainfall in the Xin′an River basin was basically same.The first main cycle of the both sets of data was 17 years,and the second and third cycles were 7 years and 3 years,respectively.At present,it is in the water-rich year in different cycles.The two sets of data were significantly correlated and had the characteristics of synchronization change.The Xin′an River Basin is a rain-fed river,and rainfall is the most important factor affecting runoff in the basin.The linear regression model was established by using two sequences of runoff and rainfall data in the Xin′an River Basin,and the fitting and forecasting effect were good,which has a certain application value in the long-term runoff forecasting service of river basin.