Abstract
Abstract Potential evapotranspiration (PET) is a comprehensive factor that characterises climate change, and considering the numerous methods to calculate PET, it is difficult to objectively select a method according to the requirements. In this study, the applicability of 12 commonly used PET estimation methods in China was studied. Based on temperature and humidity, China is divided into 11 temperature zones (TZ) and 5 arid and humid regions (AHRs). The study used the FAO Penman–Monteith (P-M) method as the standard, and the applicability of the 12 methods was analysed using four factors: correlation, annual mean values, seasonal distribution, and parameter characteristics. The results show that the radiation-based methods have the best monthly correlation with the P-M method, the temperature-based methods are second best, and mass-transfer-based methods perform the worst. Among these, the P-T method is the best, and the Hamon method is the worst. The Kharrufa and Abtew methods have the better applicability in higher TZs, whereas the Harg method has the least applicability. The seasonal distribution of radiation-based methods (excluding the Jensen method) in the different AHRs and different TZs is better than that of temperature-based and mass-transfer-based methods. According to the evaluation results of all factors, the Rohwer, P-T, and Mark methods are recommended when the data conditions are not conducive for the P-M method.
Highlights
Due to the increasing impact of human activities in recent decades, the global climate has undergone drastic changes (Cong et al ; Bao et al ; Ahn & Merwade ; Li et al )
This study analyses the applicability of 12 potential evapotranspiration (PET) methods in different arid and humid zones and temperature zones (TZ) in China using four factors: correlation analysis, annual mean values, intra-seasonal distribution, and parameter adjustments
The monthly correlation coefficients between the radiationbased methods and the FAO Penman– Monteith (P-M) method are above 0.96. This is significantly greater than the correlation coefficient values between the temperature and mass-transfer-based methods and the FAO Penman–Monteith (FAO P-M) method because the radiationbased methods consider the temperature factor
Summary
Due to the increasing impact of human activities in recent decades, the global climate has undergone drastic changes (Cong et al ; Bao et al ; Ahn & Merwade ; Li et al ). Approximately 50 methods or models are used worldwide to estimate PET, which can be divided into the following four categories: (1) temperature-based methods, (2) mass-transfer-based methods, (3) radiationbased methods, and (4) comprehensive methods (Singh & Xu ) These methods are derived experimentally or theoretically, with different test conditions, required input data, and applicability in different regions. The P-M method was used to calculate PET in China, and the results confirmed its suitability in China (Liu et al ) This formula requires a large amount of meteorological input data, such as maximum, minimum, and mean air temperatures, wind speed, relative humidity, and solar radiation. Based on existing research, this study selected the 12 methods for estimating PET, based on temperature, mass transfer, and radiation; divided China into 5 AHRs and 11 TZs; and used the FAO P-M formula as the standard. In this study, only nine TZs with stations are discussed, and the specific distribution is shown in Figure 1 and Table 2
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
