The high temporal resolution measurements of δD, δ 18 O, and deuterium excess (d ) of atmospheric water vapor provide an improved understanding of atmospheric and ecohydrological processes at ecosystem to global scales. In this study, δD, δ
18O, and d of water vapor and their flux ratios were continuously measured from May to September 2012 using an in situ technique above an arid artificial oasis in the Heihe River Basin, which has a typical continental arid climate. The monthly δD and δ
18O increased slowly and then decreased, whereas the monthly d showed a steady decrease. δD, δ O, and d from equilibrium prediction were significantly correlated with rain amount, relative humidity (RH), and air temperature (T). The "amount effect" was observed during one precipitation event. δD and δ
18O were log linear dependent on water vapor mixing ratio with respective R 2 of 17% and 14%, whereas d was significantly correlated with local RH and T, suggesting the less influence of air mass advection and more important contribution of the local source of moisture to atmospheric water vapor. Throughout the experiment, the local ET acted to increase δD and δ
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