Comparison of the Performances of Pan-Based Equations to Estimate Reference Evapotranspiration (ETo) in Mediterranean Climate Conditions

Abstract

Class A evaporation pan is often used to estimate reference evapotranspiration (ETo), considered one of the essential variables in water resource planning and irrigation scheduling. This study for Adana region conditions where the Mediterranean climate prevails aimed to compare the performances of the Snyder ETo (1995) and Ghare ETo (1996) equations which are pan-based approaches that do not require wind speed (U) and relative humidity (RH) data to estimate ETo, with the performance of the FAO24 Pan ETo equation. The FAO56-Penman–Monteith (PM) equation was used as a reference method to compare the performances of the equations. According to the research results, the Snyder ETo equation using only pan evaporation (epan) to estimate ETo has been the best equation on monthly and seasonal scales. The results showed that converting epan to reference evapotranspiration with the Snyder ETo equation can be used successfully in Adana region conditions.