Accuracy Evaluation of Standardized Precipitation Index (SPI) Estimation under Conventional Assumption in Yeşilırmak, Kızılırmak, and Konya Closed Basins, Turkey

Table 3

Theoretical probability distribution models considered in the study.

Distributions (dist.)	Parameter estimation approaches (PEA)
	Maximum likelihood (ML)	Moments (M)	L-moments (LM)
Generalized Extreme Value (GEV)	✓	✓	✓
Pearson Type III (P III)	✓	✓	✓
Three-parameter Lognormal (LN3)	✓	✓	✓
Generalized Logistic (GLOG)	✓	✓	✓
Extreme Value Type I (EVI)	✓	✓	✓
Generalized Pareto (GPAR)	✓	✓	✓
Weibull (W)	✓	✓	✓
Normal (N)	✓	✓	✓
Exponential (EXP)	✓	✓	✓
Logistic (LOG)	✓	✓	✓
Two-parameter Lognormal (LN2)	✓	✓	✓
Gamma (GAM)	✓	✓	✓
Log Pearson Type III (LP III)	✓	✓	✓
Four-parameter Wakeby (WK4)	—	—	✓
Five-parameter Wakeby (WK5)	—	—	✓