基于稳定同位素的干旱半干旱区SPAC水分运移过程研究进展

土壤-植物-大气连续体(SPAC)是生态水文学的重点研究对象，其水分运移过程对于干旱半干旱区生态植被建设和水资源综合管理具有重要意义。氢氧稳定同位素较高的灵敏性和准确度有助于揭示这一过程。介绍了氢氧稳定同位素在土壤-大气界面、土壤-地下水界面、土壤-植物界面和植物-大气界面水分补给传输过程中的应用，包括土壤水分来源和蒸发；水分补给入渗机制和滞留时间；植物水分来源和水力再分配；蒸散发分割和叶片吸水的相关研究，同时明确了氢氧稳定同位素技术在应用过程中存在的一些不确定性以及未来亟需加强的方面，以期为利用稳定同位素技术对生态水文过程的研究提供参考依据。

A review of water movement process in SPAC in the semi-arid and arid regions based on stable isotopes

Soil-plant-atmosphere continuum (SPAC) is one of the important research objects in ecohydrology, and its water movement process is of great significance for ecological vegetation construction and integrated water resources management in arid and semi-arid regions. With higher sensitivity and accuracy, hydrogen and oxygen stable isotopes were used to trace water transport processes. This paper focused on the application of hydrogen and oxygen stable isotopes in water recharge and transport at soil-atmosphere interface, soil-groundwater interface, soil-plant interface, and plant-atmosphere interface, including source and evaporation of soil water; water infiltration mechanism and residence time; plant water source and hydraulic redistribution; evapotranspiration partitioning and leaf water absorption. In addition, this paper clarified the uncertainties and limitations of hydrogen and oxygen stable isotope technology and discussed the future research direction, which might provide a reference for the study of ecohydrological processes using stable isotope techniques.