Exploring the contribution of environmental factors to evapotranspiration dynamics in the Three-River-Source region, China

•GLASS ET performed the best among three global ET products in the TRSR area.•Multi-year mean annual ET and summer ET increased by 0.609 mm/yr and 0.765 mm/yr, respectively.•Rs (33.05%) and LAI (25.29%) were the dominant control variables in shaping the interannual ET.•Long-term dynamics in summer ET were mainly controlled by LAI (35.73%) and PRE (31.19%).