Fig 1.
Extreme learning machine topology.
Fig 2.
VMD results of drought time series data.
Fig 3.
Structure flowchart of the parallel VMD-OS-QR-ELM.
Fig 4.
Relative errors of different models and cities.
Table 1.
Comparison of the numerical results for various evaluation indicators.
Table 2.
Comparison of the computing time for various models.
Table 3.
IMF reconstruction error in different scenarios.