Wang Yong, Li Xing, Zhao Yong, Yan Long, He Fan, Zhai Jiaqi, Hu Yajie, Liu Yuan, Deng Wei, Wang Zhu, Wang Qingming, Chen Minjian
State Key Laboratory of Water Cycle and Water Security, Beijing, 100038, China; China Institute of Water Resources and Hydropower Research, Beijing, 100038, China; Key Laboratory of Water Safety for Beijing-Tianjin-Hebei Region of Ministry of Water Resources, Beijing, 100038, China.
China Institute of Water Resources and Hydropower Research, Beijing, 100038, China.
J Environ Manage. 2025 Sep 20;394:127328. doi: 10.1016/j.jenvman.2025.127328.
In arid and semi-arid inland regions such as northwestern China, landscapes typically exhibit a zonal pattern from oasis to oasis-desert ecotone and then to desert, influenced by proximity to inland rivers that recharge groundwater and regulate vegetation distribution. The oasis-desert ecotone, as a transitional and ecologically fragile zone, plays a critical role in resisting desert encroachment and maintaining regional ecological stability. However, its structure and function are highly sensitive to groundwater dynamics, particularly phreatic water depth. The study employed a combination of theoretical derivation and field investigation for validation. A hydro-ecological conceptual framework was first developed by dividing the vadose zone into two functionally distinct layers: the phreatic influence zone and the root action zone. The interactions between these two zones are analyzed to elucidate the mechanisms governing vertical soil water movement in arid environments. Based on this framework, a phreatic water distribution curve is derived, and the thickness of the phreatic influence zone is quantitatively estimated. Furthermore, theoretical expressions are proposed to determine the critical groundwater burial depths demarcating the inner boundary (between oasis and ecotone) and the outer boundary (between ecotone and desert) of the transition zone. Taking the Luocheng Irrigation District in the Heihe River Basin as a case study, the thickness of the phreatic influence zone is estimated as 1.29 m, the critical groundwater depths are estimated at approximately 4∼6 m for the inner boundary and 8-13 m for the outer boundary. The findings offer theoretical support for ecological zoning, oasis restoration, and sustainable land management in arid inland river basins. Future work should expand comparative studies across diverse climatic regions and promote large-scale application of these theoretical results in ecological restoration practices.
在中国西北部等干旱和半干旱内陆地区，受靠近补给地下水并调节植被分布的内陆河流影响，地貌通常呈现出从绿洲到绿洲 - 沙漠交错带再到沙漠的带状格局。绿洲 - 沙漠交错带作为一个过渡且生态脆弱的区域，在抵御沙漠侵蚀和维持区域生态稳定方面发挥着关键作用。然而，其结构和功能对地下水动态变化高度敏感，尤其是潜水水位深度。本研究采用理论推导与实地调查相结合的方法进行验证。首先通过将包气带划分为两个功能不同的层：潜水影响层和根系作用层，构建了一个水文 - 生态概念框架。分析这两个层之间的相互作用，以阐明干旱环境中土壤水分垂直运动的控制机制。基于此框架，推导了潜水分布曲线，并定量估算了潜水影响层的厚度。此外，还提出了理论表达式来确定划分过渡带内边界（绿洲与交错带之间）和外边界（交错带与沙漠之间）的临界地下水位深度。以黑河流域的罗城灌区为例，估算出潜水影响层的厚度为1.29米，内边界的临界地下水位深度约为4至6米，外边界的临界地下水位深度为8至13米。这些研究结果为干旱内陆河流域的生态分区、绿洲恢复和土地可持续管理提供了理论支持。未来的工作应扩大不同气候区域的比较研究，并推动这些理论成果在生态恢复实践中的大规模应用。
