چکيده

One of the natural hazards that results in social, political and economic affects is drought. Due to the importance of predicting hydrological droughts in rivers, SDI River Drought Index was investigated by GRNN and GPR artificial neural network models in the Lighvan Chay watershed. Statistical parameters were used for analysis. The results showed that GPR model with determination coefficient of 0.940 and GRNN model with determination coefficient of 0.925 have good and acceptable performance in forecasting of hydrological drought in 24 months.