Abstract:
Objectives Building a calculation model for accurate reference crop evapotranspiration (ET0) prediction is important for regional water resource planning and irrigation scheduling design. This study focused on evaluating the performance of the multivariate adaptive regression spline model (MARS) in calculating the daily ET0.
Methods Firstly, ET0 calculated by the Penman-Monteith equation was used as the standard value. Secondly, daily meteorological data of the Yining station, in Yili Area, the Xinjiang Uygur Autonomous Region, China from 1996 to 2015 were adopted to construct 14 MARS models under different combinations of meteorological parameters and calculate ET0. The calculation results were compared with those of the generalized regression neural network (GRNN), support vector machine (SVM), and 10 empirical equations based on temperature, mass transfer, radiation, and meteorological parameters.
Results The calculation accuracies of MARS, GRNN, and SVM were higher than that of the empirical equations. Overall, MARS had the best performance and the highest accuracy, and SVM was slightly better than GRNN.
Conclusion MARS was the best model for estimating ET0 in this study.