Monthly runoff prediction using gated recurrent unit neural network based on variational modal decomposition and optimized by whale optimization algorithm

Abstract

To further increase the forecast precision of non-stationary non-linear monthly runoff series and improve the effectiveness of pretreatment of monthly runoff series, the whale optimization algorithm (WOA) is introduced to optimize the variational mode decomposition (VMD), and the WOA-VMD-GRU prediction model is constructed by coupling with the gating cycle unit (GRU) neural network. First, the variation modal decomposition is optimized by the whale optimization algorithm, to find the best decomposition modal number k and penalty factor α, then several IMF components are obtained according to VMD processing runoff sequences; finally, results are obtained by adding those of each component. Taking Manwan Hydropower, Hongjiadu Hydropower, and Changshui hydrological station as examples, the BP model, the GRU model, the EMD-GRU model, the CEEMDAN-GRU model, and the VMD-GRU model are compared. Four quantitative indexes were used to estimate the model performance. The results show that the WOA-VMD-GRU model has the best prediction accuracy, with correlation coefficients and Nash coefficients above 0.99 and 0.97 in the prediction results of the three hydrological stations, respectively, and avoids the low efficiency of VMD decomposition parameters in manual trial computation, providing a new way for monthly runoff prediction.

Innovative Approach to Dam Deformation Analysis: Integration of VMD, Fractal Theory, and WOA‐DELM

“…Teir model leverages VMD for denoising dam monitoring data, followed by employing LSTM neural networks for predictive analysis, thereby signifcantly improving dam deformation prediction accuracy. In order to improve the prediction accuracy of nonstationary nonlinear monthly runof series, Wang et al [22] introduced the whale optimization algorithm (WOA) to optimize the VMD and combined it with the gated recurrent unit (GRU) and constructed the runof prediction model of WOA-VMD-GRU. Te model efectively improves the efectiveness and accuracy of monthly runof sequence preprocessing.…”