Comparison of the Thornthwaite method and pan data with the standard Penman-Monteith estimates of reference evapotranspiration in China

Abstract

Various methods are available to estimate reference evapotranspiration (ET 0 ) from standard meteorological observations. The Penman-Monteith method is considered to be the most physical and reliable method and is often used as a standard to verify other empirical methods. This study estimates and compares the monthly ET 0 calculated by 3 methods at 580 Chinese stations over the last 50 yr. The Penman-Monteith method is used here as a reference, and its spatial and temporal differences with the Thornthwaite method and pan measurement are evaluated. The results show that: