Variation characteristics and attribution analysis of actual evaporation at monthly time scale from 1982 to 2019 in Jialing River Basin, China

Abstract Actual evaporation is a critical component of the water cycle and plays an important role in natural environmental change. Research on actual evaporation are significant for ecological conservation and efficient water resource utilization. Therefore, the aim of this study is to analyze the variation characteristics of monthly actual evaporation in the Jialing River (JLR) of China and quantitatively calculate the contribution of different factors to monthly actual evaporation. In this study, based on the monthly actual evaporation data of Beibei hydrological station in the JLR from 1982 to 2019. We first used cumulative anomaly and Mann-Kendall (M-K) mutation analysis methods to determine mutation year. The trend-free prewhitening M-K trend test was then used to analyze the trend of actual evaporation on a monthly scale. Finally, we applied monthly-scale Budyko model to quantitatively analyze the contribution of climate change and human activities on actual evaporation on monthly time scales. The results showed that (1) The mutation year for actual evaporation in the JLR was 1994. (2) The actual evaporation displayed a significant downward trend in January and October to December. Actual evaporation displayed a significant upward trend in March to June. (3) The distribution of monthly actual evaporation in different periods all presented an obvious “single peak” distribution. Actual evaporation reached its maximum in July. (4) The main factor leading to the actual evaporation change was climate change.