Zhu et al. (2026) Precipitation on the spatiotemporal variations of soil volumetric water content at different depths in forested catchments

Identification

• Journal: CATENA
• Year: 2026
• Date: 2026-01-23
• Authors: Hongfen Zhu, Dean F. Meason, Serajis Salekin, Priscilla Corbett-Lad, Jianming Xue
• DOI: 10.1016/j.catena.2026.109849

Research Groups

• College of Resources and Environment, Shanxi Agricultural University, Taigu, Shanxi, China
• Bioeconomy Science Institute (Scion Research), Rotorua and Lincoln, New Zealand

Short Summary

This study investigated the multiscale spatiotemporal dynamics of soil volumetric water content (VWC) across different depths (0–100 cm) in two New Zealand forested catchments, quantifying the complex interactions among VWC, precipitation, and topographic factors. It found that VWC increased with depth while its spatial variability decreased, with precipitation accounting for over 65% of temporal VWC variation and specific topographic factors significantly shaping spatial VWC distribution at deeper soil layers.

Objective

• To investigate the dynamics of soil volumetric water content (VWC) at multiple depths (0–100 cm) in two New Zealand forest catchments that differ in precipitation, soil, and geology.
• To quantify the multiscale relationships among VWC, precipitation, and topographic factors using continuous VWC data and wavelet coherency methods.

Study Configuration

• Spatial Scale: Two forested catchments in New Zealand; soil depths from 0 to 100 cm.
• Temporal Scale: Continuous VWC data collection, analyzing multiscale relationships including short-term and longer-term impacts.

Methodology and Data

• Models used: Wavelet coherency method.
• Data sources: Continuous in-situ measurements of soil volumetric water content (VWC), precipitation data, and topographic factors (e.g., topographic wetness index (TWI), planform curvature (PFC), topographic position index (TPI)).

Main Results

• Soil VWC increased with depth, while its spatial variability decreased, indicating an inverse relationship between VWC level and spatial heterogeneity.
• Precipitation was a dominant driver, accounting for over 65% of the temporal variation in VWC.
• Short-term precipitation effects were more pronounced in the humid catchment, whereas longer-term impacts were observed in the moderately humid catchment.
• Precipitation generally reduced spatial VWC variability, with this effect modulated by wet–dry cycles, tree phenological activity (active and dormant periods), and catchment-specific characteristics.
• Topographic factors, particularly TWI, PFC, and TPI, significantly influenced the spatial distribution of VWC at depths of 30–100 cm.
• The dominant topographic drivers in the topsoil (0–30 cm) varied between the two catchments.

Contributions

• Clarifies the complex, multiscale interactions among precipitation, topography, and soil depth in shaping the spatiotemporal patterns of VWC in forested catchments.
• Provides insights into VWC dynamics across different environmental contexts and soil depths, which is crucial for improving soil moisture monitoring and hydrological modeling frameworks in forested landscapes.
• Highlights the varying importance of precipitation and topographic controls on VWC dynamics depending on soil depth and catchment characteristics.

Funding

Not specified in the provided text.

Citation

@article{Zhu2026Precipitation,
  author = {Zhu, Hongfen and Meason, Dean F. and Salekin, Serajis and Corbett-Lad, Priscilla and Xue, Jianming},
  title = {Precipitation on the spatiotemporal variations of soil volumetric water content at different depths in forested catchments},
  journal = {CATENA},
  year = {2026},
  doi = {10.1016/j.catena.2026.109849},
  url = {https://doi.org/10.1016/j.catena.2026.109849}
}