Changes in potential evaporation with the extension of water-saving irrigation in Xinjiang, north-western China

Since the late 1990s, the irrigation quota in Xinjiang, northwestern China has witnessed a decline, owing to the widespread adoption of highly efficient water-saving irrigation technologies. This phenomenon prompts the question: has there been a corresponding impact on potential evaporation? To explore changes in potential evaporation resulting from irrigation advances, we conducted a comprehensive analysis spanning the years 1978–2017 in Xinjiang. Our investigation focused on a pairwise examination of agricultural stations with substantial irrigation effects, enveloped by a substantial proportion of cultivated land, and reference stations with negligible irrigation effects, surrounded by a comparatively smaller proportion of cultivated land. The findings unveiled a noteworthy reduction in potential evaporation at agricultural stations during the period 1978–1997. However, a contrasting trend emerged in the subsequent period of 1998–2017, wherein there was a significant increase in potential evaporation. In contrast, reference stations did not exhibit statistically significant reversals in potential evaporation. The observed changes in potential evaporation at agricultural stations were primarily attributed to shifts in aerodynamic components. These changes were closely associated with the reversed changes in irrigation intensity, a consequence of the widespread adoption of water-saving irrigation practices since 1998.