Precipitation Forecast of Three Stations of Lorestan Province in the Next 20 Years

Using R2, MAE, and RMSE statistical parameters, the feasibility of the LARW-WG model for producing and simulating daily rainfall data in the study areas was examined in this study. As a result, after confirming the model's capability, the HadGEM2 atmospheric general circulation model was used to forecast the changes in rainfall in the study area for the future period of 2021 to 2040. The results showed that at the confidence level of 99% there is no significant difference between the real data and the data obtained from the model, and the model has the necessary efficiency to generate daily data. According to Elshtar stations forecasted climatic parameters, annual rainfall would rise by 3.6 to 9 mm on average, and in Aliguderz station, rainfall will rise by 0.31 to 2.33 mm on average. indicated an improvement. Additionally, it is expected that the precipitation parameter in Kohdasht station would drop from -0.70 to -3.80 mm. Elshtar station showed an increase in all seasons except for spring, and Aligudarz station showed an increase in all other seasons except for summer, with the exception of Kohdasht station, which decreased in all seasons. These findings indicate that the climate in the province of Lorestan will change drastically from the current climate during the next 20 years. Kohdasht station's findings indicate that rainfall will be less than at the other two locations.