Comparison of two canopy resistance models to estimate evapotranspiration for tea and wheat in southeast China

Abstract

Actual evapotranspiration (λET) can be estimated with meteorological parameters using the Penman-Monteith (PM) model where the canopy resistance (rc) plays an important role but is difficult to determine. The Katerji-Perrier (KP) and Todorovic (TD) models are widely used to determine the rc. A comparative study was conducted to evaluate the performances of two models, on hourly and daily scales, in simulating the λET for a tea and a wheat field in southeast China. The estimated λET was compared with the measured λET by the Bowen ratio energy balance (BREB) method. The results indicated that the KP model simulated the λET of tea and wheat well for both hourly and daily scales, while the TD model simulated the λET well for the wheat for both time scales but significantly overestimated the tea λET by 44.9%. Therefore, the KP model was preferred to estimate λET for both crops, the TD model should be avoided in tea fields.