فهرست نشریات علمی دسترسی آزاد ایران

Accurate estimation of reference evapotranspiration (ET₀) is essential for effective water management in agriculture. However, ET₀ is a complex, nonlinear process influenced by many factors, and its prediction accuracy depends on the quality and combination of large, ever-growing meteorological datasets. Therefore, this study investigates the performance of the M5 tree model, the KStar algorithm, Support Vector Machines (SVM), and multiple linear regression in reducing the number of input parameters required for estimating daily reference evapotranspiration. The data used in this research include minimum and maximum temperature, average relative humidity, wind speed at two meters height, and sunshine hours, recorded at the Kuhrang station, Iran, over the period 2016–2020. The FAO Penman-Monteith model was used as the benchmark for evaluating the performance of the models. Based on data availability, various scenarios were developed for estimating ET₀ by excluding certain input variables. Evaluation metrics included Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and the correlation coefficient (R 2 ). The results showed that the M 5 tree model outperformed the other models in scenarios ( , , ) and ( , ), with correlation coefficients of R 2 = 0.96 and R 2 = 0.97, respectively. Further sensitivity analysis revealed that accurate estimation of evapotranspiration in this region requires temperature data, sunshine duration, and wind speed.