Zhang et al. (2026) Scale-dependent transition in soil moisture memory and its environmental controls in complex mountain terrain

Identification

• Journal: Hydrology and earth system sciences
• Year: 2026
• Date: 2026-06-24
• Authors: Jun Zhang, Songtang He, Yong Li, Yuan Xue
• DOI: 10.5194/hess-30-3825-2026

Research Groups

• Key Laboratory of Mountain Hazards and Engineering Resilience, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences
• State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University
• University of Chinese Academy of Sciences

Short Summary

This study investigates soil moisture memory (SMM) dynamics across three contrasting watersheds in southwestern China. The authors identify a scale-dependent transition in SMM intensity, with humid catchments exhibiting strong and persistent memory extending to multi-year scales.

Objective

• Quantify the scale-transition threshold and hierarchical drivers of SMM
• Establish a quantitative hierarchy of driving factors across temporal scales
• Propose a conceptual framework linking multi-scale SMM to differentiated hazard preconditioning mechanisms

Study Configuration

• Spatial Scale: Three hydro-climatically distinct watersheds in southwestern China (Dali River Basin, Anning River Basin, and Jiangjia Ravine)
• Temporal Scale: Daily to interannual scales (20-year record length)

Methodology and Data

• Models used: Power Spectrum Analysis (PSA), Detrended Fluctuation Analysis (DFA-2), Boruta-Random Forest algorithm
• Data sources: 12 static and dynamic covariates, daily soil moisture data from the all-weather 1 km product developed by Song et al. (2022)

Main Results

• Scale-dependent transition in SMM intensity with humid catchments exhibiting strong and persistent memory extending to multi-year scales
• Persistence horizons vary markedly across basins: longest in ARB (months to years), shortest in JJR during the rainy season (2–4 weeks)
• Key drivers of SMM identified through Boruta-RF analysis include topography, soil properties, meteorology, and vegetation

Contributions

• This study provides a framework for distinguishing short-term hydraulic preconditioning from long-term background susceptibility
• The proposed conceptual framework links multi-scale SMM to differentiated hazard preconditioning mechanisms

Funding

• National Natural Science Foundation of China (Grant No. 91837204)
• Chinese Academy of Sciences Key Research Program (Grant No. KFZD-BR-19)
• Tsinghua University Initiative Scientific Research Fund

Citation

@article{Zhang2026Scaledependent,
  author = {Zhang, Jun and He, Songtang and Li, Yong and Xue, Yuan},
  title = {Scale-dependent transition in soil moisture memory and its environmental controls in complex mountain terrain},
  journal = {Hydrology and earth system sciences},
  year = {2026},
  doi = {10.5194/hess-30-3825-2026},
  url = {https://doi.org/10.5194/hess-30-3825-2026}
}