The evapotranspiration and environmental controls of typical underlying surfaces on the Qinghai-Tibetan Plateau

To reveal the characteristics of evapotranspiration and environmental control factors of typical underlying surfaces(alpine wetland and alpine meadow) on the Qinghai-Tibetan Plateau, a comprehensive study was performed via in situ observations and remote sensing data in the growing season and non-growing season. Evapotranspiration was positively correlated with precipitation, the decoupling coefficient, and the enhanced vegetation index, but was energy-limited and mainly controlled by the vapor pressure deficit and solar radiation at an annual scale and growing season scale, respectively. Compared with the non-growing season, monthly evapotranspiration, equilibrium evaporation, and decoupling coefficient were greater in the growing season due to lower vegetation resistance and considerable precipitation. However, these factors were restricted in the alpine meadow. The decoupling factor was more sensitive to changes of conductance in the alpine wetland. This study is of great significance for understanding hydro-meteorological processes on the Qinghai-Tibetan Plateau.