Li et al. (2026) Soil water vapor adsorption and condensation governed by groundwater depth and vadose zone lithology in arid and semi-arid regions

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-02-14
• Authors: Ran Li, Haibo Feng, Yanhong Xue, Jianwei Zhou, Lei Fang, Danhui Su, Xiaoming Zheng, Siqi Tan, Huyuan Zheng, Yongxiang Ma
• DOI: 10.1016/j.jhydrol.2026.135137

Research Groups

• School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
• School of Geography and Information Engineering, China University of Geosciences, Wuhan 430074, China
• Key Laboratory of Mine Ecological Effects and Systematic Restoration, Ministry of Natural Resources, Beijing 100081, China
• Institute of Hydrogeology and Environmental Geology of Ningxia Hui Autonomous Region, Yinchuan 750011, China
• China Earthquake Networks Center, Beijing 100045, China
• Geological Environment Center of Hubei Province, Wuhan 430051, China
• Institute of Geological Survey, China University of Geosciences, Wuhan 430074, China
• Ningxia Bureau of Coal Geological Exploration, Yinchuan 750011, China

Short Summary

This study quantitatively analyzed the spatiotemporal dynamics of soil water vapor adsorption and condensate formation in arid regions, revealing the distinct impacts of groundwater depth and vadose zone lithology, and highlighting an overestimation in conventional condensation measurements due to unseparated adsorption.

Objective

• To elucidate the mechanistic effects of varying groundwater depths and vadose zone lithologies on vapor adsorption and condensate formation.
• To establish a quantitative foundation for precise estimation of condensate water in arid and semi-arid regions and deepen the mechanistic understanding of associated ecohydrological processes.

Study Configuration

• Spatial Scale: Arid Yinchuan region of Ningxia, China, using nine laboratory soil columns.
• Temporal Scale: Diurnal cycles of vapor adsorption and condensation; experimental observation period not explicitly stated but implies continuous monitoring.

Methodology and Data

• Models used: Not explicitly stated; the study is experimental.
• Data sources: Experimental data collected from nine soil columns with varying lithologies and groundwater levels, using layered microlysimeter weighing and temperature-humidity monitoring at different soil depths.

Main Results

• Shallow groundwater serves as a significant vapor source for condensate formation, with its contribution diminishing as groundwater depth increases.
• Water vapor adsorption predominantly occurs in the 0–5 cm soil layer (approximately 0.1 mm d⁻¹) during 19:00–01:00, while adsorption in the 5–10 cm layer primarily occurs during 10:00–13:00.
• With increasing groundwater depth, the dominant vapor source for condensate formation transitions from soil pore vapor to atmospheric vapor; at a groundwater depth of 2.5 m, its vapor contribution to condensate formation in fine sand and silt soils approaches critical thresholds.
• Under identical groundwater depth conditions, finer-textured soils exhibit greater condensate quantities and prolonged condensation durations.
• Conventional microlysimeter methodology may overestimate condensate quantities in arid regions; water vapor adsorption contributes approximately 40% on average to soil mass increment in the 0–5 cm layer, with this proportion increasing under greater groundwater depths.

Contributions

• Provides a quantitative differentiation between soil water vapor adsorption and condensation, addressing a gap in previous research that led to substantial overestimation of condensation water.
• Offers a detailed mechanistic understanding of how groundwater depth and vadose zone lithology govern vapor adsorption and condensate formation in arid and semi-arid regions.
• Establishes a quantitative foundation for more precise estimation of condensate water, improving ecohydrological modeling and water resource management in water-scarce environments.

Funding

Not explicitly stated in the provided text.

Citation

@article{Li2026Soil,
  author = {Li, Ran and Feng, Haibo and Xue, Yanhong and Zhou, Jianwei and Fang, Lei and Su, Danhui and Zheng, Xiaoming and Tan, Siqi and Zheng, Huyuan and Ma, Yongxiang},
  title = {Soil water vapor adsorption and condensation governed by groundwater depth and vadose zone lithology in arid and semi-arid regions},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.135137},
  url = {https://doi.org/10.1016/j.jhydrol.2026.135137}
}