Ali Danandeh MehrMir Jafar Sadegh SafariVahid NouraniMehr, Ali DanandehNourani, VahidSafari, Mir Jafar SadeghDanandeh Mehr, Ali2025-10-06202113003453, 030027211300-345310.18400/TEKDERG.6054532-s2.0-85091895889https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091895889&doi=10.18400%2FTEKDERG.605453&partnerID=40&md5=09f3e4c25ab4fbd5c027d61dce44d852https://gcris.yasar.edu.tr/handle/123456789/9119https://search.trdizin.gov.tr/en/yayin/detay/535348https://doi.org/10.18400/tekderg.605453https://doi.org/10.18400/TEKDERG.605453This study presents developing procedures and verification of a new hybrid model namely wavelet packet-genetic programming (WPGP) for short-term meteorological drought forecast. To this end the multi-temporal standardized precipitation evapotranspiration index (SPEI) has been used as the drought quantifying parameter at two meteorological stations at Ankara province Turkey. The new WPGP model comprises two main steps. In the first step the wavelet packet which is a generalization of the well-known wavelet transform is used to decompose the SPEI series into deterministic and stochastic sub-signals. Then classic genetic programming (GP) is applied to formulate the deterministic sub-signal considering its effective lags. To characterize the stochastic component different theoretical probability distribution functions were assessed and the best one was selected to integrate with the GP-evolved function. The efficiency of the new model was cross-validated with the first order autoregressive (AR1) GP and random forest (RF) models developed as the benchmarks in the present study. The results showed that the WPGP is a robust model superior to AR1 and RF and significantly increases the predictive accuracy of the standalone GP model. © 2023 Elsevier B.V. All rights reserved.Englishinfo:eu-repo/semantics/openAccessDrought, Genetic Programming, Spei, Stochastic Modelling, Wavelet Packet, Distribution Functions, Forestry, Genetic Algorithms, Genetic Programming, Stochastic Models, Stochastic Systems, Wavelet Analysis, Wavelet Transforms, Weather Forecasting, Deterministics, Genetic Programming Modeling, Hindcasting, Hybrid Model, Meteorological Drought, Meteorological Station, Multi-temporal, Standardized Precipitation Evapotranspiration Index, Stochastic-modeling, Wavelet Packet, DroughtDistribution functions, Forestry, Genetic algorithms, Genetic programming, Stochastic models, Stochastic systems, Wavelet analysis, Wavelet transforms, Weather forecasting, Deterministics, Genetic programming modeling, Hindcasting, Hybrid model, Meteorological drought, Meteorological station, Multi-temporal, Standardized precipitation evapotranspiration index, Stochastic-modeling, Wavelet Packet, DroughtGenetic ProgrammingSPEIWavelet PacketMeteoroloji Ve Atmosferik BilimlerDroughtStochastic ModellingArticle