Evolution Characteristics Of Potential Evapotranspiration Over The Three-River Headwaters Region

This study investigates the evolution characteristics of potential evapotranspiration (PET) over the Three-River Headwaters Region (TRHR) based on observations at 14 stations during 1960-2014. First, the spatial-temporal changes were analysed at annual and seasonal scales, and the results indicated that: (1) the central part had the lowest annual mean PET; (2) the mean PET in spring and summer was much higher than that in autumn and winter; and (3) PET firs5tly decreased, and then increased from the 1980s. Second, the monthly PET over the TRHR for the near future was predicted using Back-Propagation Neural Networks (BPNN) and Long Short-Term Memory (LSTM), and the predictions showed increasing trends. The major contribution of this study is to build the models for prediction of the monthly PET based on limited observations. Overall, the outcomes can help us to better understand the future hydrometeorological conditions in the TRHR, which would be valuable for better protection of the ecological environment in this region.