A method for judging the non-stationarity of hydrological time series

Abstract

The invention discloses a method for discriminating the non-stationarity of a hydrological time series, comprising: determining a specific ensemble empirical mode decomposition method; decomposing the series; using the energy diffusion function of white noise to identify all periodic components in the original series; Remove the periodic components in the original sequence and use the remaining components as a new sequence; select an appropriate model equation for fitting; use the selected model equation to perform a unit root test on the new sequence; use the autocorrelation coefficient diagram and partial correlation coefficient diagram for further analysis Statistical properties of the new sequence; compare the consistency of the auto(partial) correlation coefficient results with the unit root test results; if the new sequence in question shows a good correlation, and the characteristic statistics of the unit root test accept the null hypothesis, it indicates that the sequence Non-stationary; if the results of the two are inconsistent, the sequence is considered non-stationary. The invention overcomes the influence of the sequence period item on the unit root test result, and obtains the accurate sequence non-stationary test result.

Description

technical field [0001] The invention belongs to the technical field of hydrology, and particularly refers to a method for judging the non-stationarity of hydrology time series. Background technique [0002] Revealing the changing characteristics and evolution laws of natural water cycle processes is an important basis for solving complex and intersecting water problems, so it has always been a core research topic in the field of hydrology. In practice, it is a very difficult scientific problem to accurately understand the complex changing characteristics of the water cycle process. Especially in recent decades, due to the continuous impact of climate change and human activities, the natural water cycle process in many river basins has been destroyed, the characteristics of the cycles and trends of major water cycle elements have changed, the relationship between rainfall and runoff has changed significantly, and flood disasters have also changed. Extreme hydrological events...

AI Technical Summary

Problems solved by technology

[0006] In view of the above problems, the purpose of the present invention is to provide a method for discriminating the non-stationarity of hydrological time series, so as to solve the problem that the prior art method of eliminating the influence of sequence period items cannot accurately describe and describe the period size and period in the actual hydrological time series Periodic terms with complex and variable volatility

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