Research on Time Series Decomposition Method for Groundwater Seepage Pressure on Slopes
The observation data of groundwater seepage pressure is a typical time series with nonlinear,non-stationary,and fuzzy characteristics,and its statistics are time-varying functions.It is difficult to determine the degree of influence and periodic changes of various factors on groundwater seepage pressure through direct observation methods.Therefore,it is necessary to choose a decomposition method suitable for non-stationary time series and good decomposition effect for groundwater seepage pressure monitoring data.Using MATLAB software,empirical mode decomposition(EMD),variational mode decomposition(VMD),and variational mode decomposition(SSA-VMD)based on sparrow search algorithm were used to analyze the groundwater seepage pressure data of a slope in Lianyungang.The results show that the sparrow search algorithm can greatly preserve the physical meaning of each component in optimizing the combination of VMD parameters.The decomposed results can reflect the time-frequency distribution characteristics of groundwater seepage pressure in each component and the influence of environmental factors on each component,proving that the optimized VMD parameters have better engineering practical significance.