Gao et al. (2026) Spatiotemporal dynamics and scale-dependent similarity of soil moisture on hillslopes in the Mu Us Sandy Land, China

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-29
• Authors: Wande Gao, Xiong Feng, Zhongqiang Jin, Xiuhua Liu, Changchun Shi
• DOI: 10.1016/j.ejrh.2026.104030

Research Groups

• School of Hydraulic Engineering, Lanzhou Resources & Environment Voc-Tech University
• Yellow River Basin Ecotope Integration of Industry and Education Research Institute
• School of Water and Environment, Chang’an University
• Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of Ministry of Education
• Key Laboratory of Eco-hydrology and Water Security in Arid and Semi-arid Regions of Ministry of Water Resources
• Observation and Research Station of Mu Us Sandland Ecosystem in Yulin Shaanxi, National Forestry and Grassland Administration

Short Summary

This study investigated the spatiotemporal dynamics of soil moisture on hillslopes in the Mu Us Sandy Land, China. The results showed that soil moisture similarity generally decreased with increasing depth interval, and wavelet coherency analysis revealed significant relationships between surface and deeper layers at short to medium scales.

Objective

• Quantify the temporal similarity of soil moisture among different depths and slope positions using Spearman’s rank correlation.
• Identify time- and scale-dependent coherence among soil moisture series and between soil moisture and meteorological drivers using wavelet coherency analysis.
• Use phase relationships and lag patterns to infer vertical infiltration and lateral redistribution processes.

Study Configuration

• Spatial Scale: Hillslope scale, with measurements conducted at 3 topographic locations on the slope: upslope, midslope, and footslope.
• Temporal Scale: Hourly observations from October 2021 to October 2022.

Methodology and Data

• Models used: Wavelet coherency analysis and Spearman’s rank correlation.
• Data sources: Field measurements of soil moisture using TDR probes, meteorological data from an automatic weather station.

Main Results

• Soil moisture similarity generally decreased with increasing depth interval.
• Wavelet coherency analysis revealed significant relationships between surface and deeper layers at short to medium scales.
• Phase relationships indicated delayed vertical infiltration and lateral redistribution toward footslope positions during wet periods.

Contributions

• This study provides new insights into the spatiotemporal dynamics of soil moisture on hillslopes in the Mu Us Sandy Land, China.
• The results have implications for understanding hydrological processes on sandy hillslopes and can inform management practices to improve water conservation and ecosystem restoration.

Funding

• National Natural Science Foundation of China (Grant No. 51979215)
• Key Research and Development Program of Shaanxi Province (Grant No. 2020ZDLGY03-02)

Citation

@article{Gao2026Spatiotemporal,
  author = {Gao, Wande and Feng, Xiong and Jin, Zhongqiang and Liu, Xiuhua and Shi, Changchun},
  title = {Spatiotemporal dynamics and scale-dependent similarity of soil moisture on hillslopes in the Mu Us Sandy Land, China},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.104030},
  url = {https://doi.org/10.1016/j.ejrh.2026.104030}
}