Wang et al. (2025) Improvement of the hillslope-storage Boussinesq model by incorporating rainfall infiltration effects

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-11-07
• Authors: Kexin Wang, Jun Kong, Zhaoyang Luo, Xuejun Feng, Yifeng Zhang
• DOI: 10.1016/j.jhydrol.2025.134562

Research Groups

• Hydrologic-Cycle and Hydrodynamic System of Ministry of Water Resources, Hohai University, Nanjing 210024, China
• Department of Civil and Environmental Engineering, National University of Singapore, Singapore 119077, Singapore

Short Summary

This study develops a novel coupled hillslope-storage Boussinesq (hsB) and Green-Ampt (GA) infiltration model to improve the simulation of hillslope hydrological responses by incorporating rainfall infiltration, demonstrating superior performance over the conventional hsB model. The new model enables continuous simulation from rainfall onset through post-event drainage, capturing complex hydrodynamic features across various soil types and rainfall intensities.

Objective

• To improve the hillslope-storage Boussinesq (hsB) model's accuracy in simulating hillslope hydrological responses by integrating the Green-Ampt (GA) infiltration mechanism, thereby enabling continuous simulation from rainfall onset through post-event drainage across various soil types and rainfall intensities.

Study Configuration

• Spatial Scale: Hillslope scale (conceptual/numerical, typically tens to hundreds of meters).
• Temporal Scale: Event-based to short-term continuous simulation, covering rainfall onset through post-event drainage (hours to days).

Methodology and Data

• Models used: Hillslope-storage Boussinesq (hsB) model, Green-Ampt (GA) infiltration model (coupled). Comparison made with conventional hsB model and Richards equation.
• Data sources: Numerical simulations and theoretical analysis. No external observational or reanalysis data sources are explicitly mentioned for validation in the provided text.

Main Results

• Under low-intensity rainfall, hillslope drainage exhibits a simple monotonic recession.
• High-intensity rainfall induces a distinct multi-phase hydrological response:
  • Early stage: Dynamic changes between the wetting front and groundwater level lead to redistribution of soil moisture and matric suction in the unsaturated zone.
  • Mid-rainfall stage: The wetting front intersects the groundwater table, causing a rapid rise in groundwater level and a sharp increase in internal drainage rates, potentially leading to saturation or surface overflow.
  • Post-rainfall stage: Natural hillslope drainage resumes, accompanied by a gradual decline in discharge rates.
• Soils with different hydraulic conductivities exhibit varied drainage patterns throughout these stages.
• The proposed coupled model demonstrates superior performance in simulating hillslope hydrological responses compared to the conventional hsB model.
• The coupled model offers improved computational efficiency and reduced parameter requirements relative to approaches involving the Richards equation.

Contributions

• Development of a novel coupled model integrating the Green-Ampt infiltration mechanism into the hillslope-storage Boussinesq (hsB) framework.
• Enables continuous simulation of hillslope hydrological responses from rainfall onset through post-event drainage, addressing a key limitation of previous hsB models.
• Captures complex hydrodynamic features across different soil types and rainfall intensities, including multi-phase responses to high-intensity rainfall.
• Demonstrates superior simulation performance compared to the conventional hsB model.
• Offers a computationally efficient alternative to Richards equation-based approaches for incorporating infiltration into hillslope subsurface flow models, with reduced parameter requirements.

Funding

• Not explicitly mentioned in the provided text.

Citation

@article{Wang2025Improvement,
  author = {Wang, Kexin and Kong, Jun and Luo, Zhaoyang and Feng, Xuejun and Zhang, Yifeng},
  title = {Improvement of the hillslope-storage Boussinesq model by incorporating rainfall infiltration effects},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134562},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134562}
}