Reference Evapotranspiration Prediction from Limited Climatic Variables Using Support Vector Machines and Gaussian Processes

Abstract

Climatic variables collected from weather stations evenly distributed in all regions of Turkey were used to study the potential of Gaussian Process Regression (GPR) and Support Vector Regression (SVR) in predicting reference evapotranspiration (ET0). The variables used as input features for the GPR and SVR models were solar radiation, mean temperature, wind speed, relative humidity, and month of the year. The corresponding ET0 values were calculated using the Food and Agriculture Organization recommended equation FAO 56 PM using climatic measurements collected from the same stations. Results show that regression models with high accuracies are possible using GPR and SVR models. The most effective input variable for ET0 prediction was found to be solar radiation. Relative humidity had the lowest impact on model accuracies.