Studying the temporal and spatial variations of potential evapotranspiration (ET0) in the Hexi Corridor region and its response to climatic factors is of great significance for improving the utilization efficiency of agricultural water resources. The temporal and spatial characteristics of ET0 and the six meteorological factors influencing the variation of ET0 in the FAO P-M formula during 1960–2019 have been revealed based on the statistical analysis method and the spatial interpolation method. Qualitative methods such as principal component analysis, cluster analysis, and grey relational grade were organically combined with quantitative methods such as sensitivity analysis and contribution rate calculation to comprehensively and objectively reveal the response relationship of ET0 to climate factors. The results showed that ET0 in the Hexi corridor showed a fluctuating increase during the period 1960–2019, and the change points were 1969 and 2002, respectively. ET0 increased from the southeast to the northwest, with a range from 812.3 to 1516.6 mm. Temperature factors such as Rn, Tmean, Tmax, and Tmin, change closely with ET0, followed by humidity and wind speed factors. The increase in ET0 is the most sensitive to the decrease in Rn, followed by the decrease in u2 and the increase in Tmean. Increasing Tmean was the main reason for increasing ET0, followed by u2 and Rn, and the combined contribution of the six meteorological factors was 72.39% during 1960–2019. This study has revealed the response of ET0 to climate factors, providing a scientific reference for more rational planning and efficient utilization of water resources in arid and semi-arid regions.
Ma et al. (Thu,) studied this question.