Variation in Reference Evapotranspiration over the Tibetan Plateau during 1961–2017: Spatiotemporal Variations, Future Trends and Links to Other Climatic Factors

• Published in: Water (Basel) Vol. 12; no. 11; p. 3178
• Main Authors: Liu, Yuan, Wang, Qianyang, Yao, Xiaolei, Jiang, Qi, Yu, Jingshan, Jiang, Weiwei
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.11.2020
• Subjects: abrupt change; ET0; meteorological elements; Morlet wavelet; Spearman correlation
• ISSN: 2073-4441; 2073-4441
• DOI: 10.3390/w12113178

Reference evapotranspiration (ET0) is a key factor in the hydrological cycle and energy cycle. In the context of rapid climate change, studying the dynamic changes in ET0 in the Tibetan Plateau (TP) is of great significance for water resource management in Asian countries. This study uses the Penman–Monteith formula to calculate the daily ET0 of the TP and subsequently uses the Mann–Kendall (MK) test, cumulative anomaly curve, and sliding t-test to identify abrupt change points. Morlet wavelet analysis and the Hurst index based on rescaled range analysis (R/S) are utilized to predict the future trends of ET0. The Spearman correlation coefficient is used to explore the relationship between ET0 changes and other climate factors. The results show that the ET0 on the TP exhibited an increasing trend from 1961 to 2017, with the most significant increase occurring in winter; an abrupt change to a tendency to decrease occurred in 1988, and another abrupt change to a tendency to increase occurred in 2005. Spatially, the ET0 of the TP shows an increasing trend from east to west. The change trend of the ET0 on the TP will not be sustainable into the future. In addition, the mean temperature has the greatest impact on the ET0 changes in the TP.