Considering the climate change and the drastic change in land use, the use of long-term meteorological data in irrigation management is not necessary. Evaporation - transpiration of plants is one of the most basic and important parameters that is necessary and important in estimating water needs and managing farm irrigation. Therefore, the use of real-time data and the forecasting of meteorological models, provided that they have the necessary accuracy and precision, can be useful in the implementation of farm irrigation management. The purpose of this research was to check the forecasting accuracy of available meteorological models and to eva‎luate their accuracy and accuracy with ground data and to check their effect on corn yield. The desired data for four meteorological station locations in Golpayegan, Faridan, Ardestan and Semiram cities were received from the site. The data included the seven-day forecast of maximum temperature, minimum temperature, average daily wind speed and percentage of cloudiness. The mentioned data was also received from the Meteorological Department of Isfahan province for the mentioned stations. The difference between actual data (STN) and site forecast (WSI) or updated site data (WST) and site forecast data (WSP) was calculated and eva‎luated. In the review of seven-day WST data with WSP data, it was observed that the highest value of NRMSE related to freezing at the minimum temperature was 4.6% and for the maximum temperature it was 3.2%. In the comparison between STN data and WSP data, the lowest NRMSE value for maximum (4.5) and minimum (1.4) temperatures is related to Golpayegan. The eva‎luation of corn crop performance with NRMSE showed that Golpayegan city had the best performance with NRMSE 2.43% and in the eva‎luation conducted for the evaporation-transpiration of corn plant, Feridan city was the best treatment with NRMSE 1.45. It can be concluded from the obtained data that the use of one-day forecast data from the meteorological site has good and reliable results and can be used for irrigation management in the absence of access to timely data. But as the number of forecasting days increases, the amount of error increases and the data is not reliable.

مهدي قيصري

عليرضا گوهري

سعيد اسلاميان , امين اله معصومي