Improved Monthly Runoff Time Series Prediction Using the CABES-LSTM Mixture Model Based on CEEMDAN-VMD Decomposition

Accurate runoff prediction is vital in optimizing reservoir scheduling, efficiently managing water resources, and ensuring the effective utilization of water resources. In this paper, a hybrid prediction model combining complete ensemble empirical mode decomposition with adaptive noise, variational mode decomposition, CABES, and long short-term memory network (CEEMDAN-VMD-CABES-LSTM) is proposed. Firstly, CEEMDAN is used to decompose the original data, and the high-frequency component obtained from the CEEMDAN decomposition is decomposed using VMD. Then, each component is input into the LSTM optimized by CABES for prediction. Finally, the results of individual component predictions are combined and reconstructed to produce the monthly runoff predictions. The hybrid model is employed to predict the monthly runoff at the Xiajiang hydrological station and the Yingluoxia hydrological station. A comprehensive comparison is conducted with other models including BP, LSTM, SSA-LSTM, bald eagle search (BES)-LSTM, CABES-LSTM, CEEMDAN-CABES-LSTM, and VMD-CABES-LSTM. The assessment of each model's prediction performance uses four evaluation indexes. Results reveal that the CEEMDAN-VMD-CABES-LSTM model showcased the highest forecast accuracy among all the models evaluated. Compared with the single LSTM, the root mean square error (RMSE) and mean absolute percentage error (MAPE) of the Xiajiang hydrological station decreased by 71.09 and 65.26%, respectively, and the RMSE and MAPE of the Yingluoxia hydrological station decreased by 65.13 and 40.42%, respectively. The R and Nash efficiency coefficient (NSEC) values obtained for both sites are near 1.