Zhou et al. (2026) Slope-Controlled Partitioning of Vertical and Lateral Solute Transport Pathways Revealed by Inclined Leaching Experiments

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water
• Year: 2026
• Date: 2026-03-23
• Authors: Xiaoli Zhou, Jiakun Dong, Buxu Sun, Ziyi Yang, Xiaoping Sun, Yu Shen
• DOI: 10.3390/w18060753

Research Groups

Not available from the provided text.

Short Summary

This study investigated how slope influences the partitioning of vertical and lateral transport pathways for a highly mobile solute (PFOA) using laboratory-scale experiments. It found that solute transport shifts from vertical-dominated under flat conditions to lateral-dominated at moderate slopes, a shift well described by an exponential partitioning model with a critical crossover at approximately 4° slope.

Objective

• To investigate how slope influences the partitioning of vertical and lateral transport pathways for highly mobile solutes.

Study Configuration

• Spatial Scale: Laboratory-scale inclined leaching experiments (controlled soil columns).
• Temporal Scale: Experimental, short-term leaching events (varied flow regimes and leaching volumes).

Methodology and Data

• Models used: Exponential partitioning model: f1(α) = fmax (1 − e−kα)
• Data sources: Laboratory-scale inclined leaching experiments with systematically varied slope angles (0°, 4°, 9°, and 20°), flow regimes, and leaching volumes.

Main Results

• Solute migration shifted from vertical-dominated transport under flat conditions (91% of recovered mass at 0° slope) to lateral-dominated export at moderate slopes.
• Lateral pathways accounted for up to 75% of the recovered mass at a 9° slope.
• This pathway shift was well described by an exponential partitioning model, f1(α) = fmax (1 − e−kα), with fmax = 0.80 and k = 0.34°−1 (R2 = 0.97).
• A critical crossover threshold from vertical to lateral dominance was observed at approximately 4° slope.
• Flow regime interacted with slope angle: slower flow enhanced lateral export at moderate slopes, while faster flow promoted peak lateral transport under steeper conditions.
• Solid-phase retention remained consistently low (5–9%) across all treatments, indicating hydrological pathway partitioning as the primary control.

Contributions

• Demonstrates that even modest topographic gradients can fundamentally alter solute transport pathways in sloped soils.
• Provides a process-based, slope-dependent pathway partitioning framework for incorporating lateral transport into hillslope hydrological models.
• Improves assessments of contaminant redistribution in both managed and natural landscapes by quantifying lateral transport under controlled conditions.

Funding

Not available from the provided text.

Citation

@article{Zhou2026SlopeControlled,
  author = {Zhou, Xiaoli and Dong, Jiakun and Sun, Buxu and Yang, Ziyi and Sun, Xiaoping and Shen, Yu},
  title = {Slope-Controlled Partitioning of Vertical and Lateral Solute Transport Pathways Revealed by Inclined Leaching Experiments},
  journal = {Water},
  year = {2026},
  doi = {10.3390/w18060753},
  url = {https://doi.org/10.3390/w18060753}
}