Abstract
The selection of suitable reference evapotranspiration (ETo) models in case of climatic data scarcity is a challenging task as it plays a pivotal role in agriculture and water resource management. Therefore, the research work deals with selecting the appropriate mass transfer reference evapotranspiration model using multi criteria decision technique (MCDM) in a semi-arid region of the southern part of Kingdom of Saudi Arabia i.e., Abha. The ten mass transfer methods with ten criteria (statistical indices) using available weather parameters from 1980 to 2018 have been illustrated in this study. Models were calibrated (1980-2006) and validated for the period (2007-2018). The objective weight was computed by criteria importance through inter criteria correlation (CRITIC) method and performance score by weighted sum model (WSM), weighted product model (WPM), weighted aggregates sum product assessment (WASPAS) and evaluation based on distance from average solution (EDAS) methods which in turn rank the evapotranspiration method. The rankings obtained from MCDM techniques were validated with ranking by GPI method using spearman ranking coefficient. The result from MCDM shows that Saif model is the best model and that also GPI yielded same result. The methodology applied in this study can be adopted in any other region which in turns proved to be beneficial for crop cultivators, crop advisors, researchers, and water resource management.