Preprint Article Version 1 This version is not peer-reviewed Version 1 : Received: 27 May 2024 / Approved: 27 May 2024 / Online: 27 May 2024 (08:44:17 CEST) Duong, H. H.; Phong, N. D.; Ha, T. L.; Tang, T. D.; Trinh, T. N.; Nguyen, T. M.; Nguyen, T. M. Application of Machine Learning to Forecast Drought Index for the Mekong Delta. Preprints 2024, 2024051693. https://doi.org/10.20944/preprints202405.1693.v1 Duong, H. H.; Phong, N. D.; Ha, T. L.; Tang, T. D.; Trinh, T. N.; Nguyen, T. M.; Nguyen, T. M.