“…In this regard, SPI is a non-linear method based on the drought prediction by conventional statistical methods with great uncertainty. Recently, the implementation of machine learning (ML) algorithms in SPI estimation and modeling such as support vector regression (SVR) (Belayneh et al, 2014;Borji et al, 2016), extreme learning machine (ELM) (M. Liu et al, 2021;Park et al, 2016), linear genetic programming (LGP) (Mehr et al, 2014), adaptive regression spline (MARS) (Deo et al, 2017), extremely randomized tree (ERT) , adaptive neuro-fuzzy inference system (ANFIS) (Gocić et al, 2015;Nguyen et al, 2015), artificial neural network (ANN) (Banadkooki et al, 2021;Deo and Şahin, 2015), M5 Tree (M5T) (Yaseen et al, 2021), and random forest (RF) (Danandeh Mehr et al, 2020; have presented huge potentials with promising results in estimating and modeling drought compared to conventional methods.…”