黄河径流变化规律的小波分析

A wavelet analysis on Yellow River runoff variation law

以黄河为研究对象,从系统的观点出发,同时考虑时空变化条件,采用不同类型的小波变换对其上、中、下游的径流变化过程进行了周期性检验、突变点检测和趋势性分析。研究结论表明:黄河径流在不同的时间尺度所对应的径流丰枯变化是不同的,大尺度的丰枯变化中嵌套着较小尺度下的丰枯变化,呈现较为复杂的丰枯结构。为此,黄河径流变化具有多层次结构和局部特征,某个周期变化在某一时段表现明显,但在其他时段表现可能并不明显,周期变化仅在特定的时段内才有意义。因而,径流时间序列的长度会影响分析结果,随着径流序列的延长,可以分析出径流变化更长的周期特征。本研究可以为黄河流域水资源开发利用和减灾防灾提供相关科学依据。

By taking the Yellow River as the study object,the periodic inspection,mutation detection and trend analysis are made from a systematic viewpoint on the runoff variation processes of the up,middle and downstream of the river with the various wavelet transformations under the consideration of the spatio-temporal variation condition.It is concluded that the variations of rich-poor runoffs of the river are different in correspondence with various temporal scales concerned,i.e.the rich-poor variation on a larger scale is inserted with that on a smaller scale,which shows a more complicated structure.Therefore,the runoff variation of the Yellow River has a multi-level structure with local features;of which a periodical variation is to be obvious within a certain period of time,but is not to be so obvious within the other periods of time,and the related periodical variation is to be significant within a specific period of time.As a result,the length of the time series of runoff is to impact the result from the analysis concerned.Moreover,the longer periodical feature of the runoff variation can be analyzed along with the prolonged runoff series.Generally,this study can provide a relevant scientific basis for the water resources development and disaster mitigation of the Yellow River basin.