2.2 ET measurement and data quality control
The daily actual ET was measured by large-scale weighing lysimeters (height 2 m, diameter 1 m, and resolution 0.01 mm) (Fig.1c), half-hourly averaged ET was recorded with a data logger (CR1000, Campbell, USA). To ensure data quality, all negative or abnormal ET values caused by falling soil particles were discarded; the abnormal ET values were these outlier that more than three times of average ET, this screening process yielded 324 days of data spanning 8 June 2017 to 19 September 2018. According to in-situ phenological observations of the foliage of dominant plants, we defined the growing season as that from May 1stto September 30th, while the period from October 1st to April 30th of the following year is defined as the non-growing season (Zhang et al., 2018).