Increasing Tibetan Plateau terrestrial evapotranspiration primarily driven by precipitation

• Long-term mean TP-averaged annual ET is 353±24 mm, with 64% from soil evaporation. Annual TP increased significantly during 1982–2016. Precipitation enhancement the dominant driver of increase in ET. The drivers trend are spatially heterogeneous over TP. Vegetation change plays a less important role than climatic factors trend. While terrestrial evapotranspiration ( ) Tibetan Plateau (TP) key modulating water storage Asian Water Tower, magnitude, trend, and remain poorly understood this region due partially to sparse ground measurements. This study used water-carbon coupled biophysical model, Penman-Monteith-Leuning Version 2 (PML_V2), characterize variations across 1982–2016 its drivers. Model parameters PML_V2 were calibrated against ground-observed data 14 eddy-covariance flux towers. Plot- basin-scale validations demonstrate that robust enough simulating both magnitude . 35-year rates decrease southeastern northwestern TP, leading value 353 ± 24 mm yr −1 Soil evaporation main component (64%) , followed by plant transpiration (31%) canopy (5%). From 1982 2016, rate 1.87 0.25 −2 p < 0.001) primarily precipitation enhancement. Spatially, controls most parts except certain regions eastern where net radiation temperature do so instead, respectively. because 68% area dryland aridity index 0.65. LAI appears climate much relative contribution exceeds 20% many indicating vegetation played nonnegligible regulating varied substantially. Our results vital importance for facilitating understanding hydrological processes Tower.