Tai et al. (2025) Accurate reproduction of sub-hourly rainfall extremes in Poisson cluster rainfall models with a variable sinusoidal pulse

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-12-21
• Authors: Chi Vuong Tai, Dongkyun Kim, Christian Onof, Li-Pen Wang, Jeongha Park
• DOI: 10.1016/j.jhydrol.2025.134821

Research Groups

• Department of Civil Engineering, Hongik University, the Republic of Korea
• Department of Civil and Environmental Engineering, Imperial College London, UK
• Department of Civil Engineering, National Taiwan University, Taiwan

Short Summary

This study introduces RBL7, a refined Poisson cluster rainfall model with variable sinusoidal rain cells, to accurately reproduce sub-hourly rainfall extremes. It demonstrates that RBL7 outperforms existing models in capturing rainfall extremes and standard statistics across various timescales, despite being calibrated only at hourly and supra-hourly scales.

Objective

• To introduce and evaluate the Randomized Bartlett-Lewis Rectangular Pulse model version 7 (RBL7), which uses variable sinusoidal rain cell shapes, for its ability to accurately reproduce sub-hourly rainfall extremes and standard rainfall statistics across multiple timescales.

Study Configuration

• Spatial Scale: Point scale (single gauge station).
• Temporal Scale: Data record of 69 years; analysis of rainfall characteristics across timescales from 5 minutes to a decade; model calibrated at hourly and supra-hourly timescales.

Methodology and Data

• Models used:
  • Randomized Bartlett-Lewis Rectangular Pulse model version 7 (RBL7)
  • Original Bartlett-Lewis Rectangular Pulse model (OBL)
  • Existing models using rectangular shapes or sine functions with a constant power of 2 (for comparison)
• Data sources:
  • 69-year record of rainfall data from a gauge station in Bochum, Germany (observation).

Main Results

• The RBL7 model accurately reproduces rainfall extremes across sub-hourly to supra-daily timescales.
• RBL7 outperforms existing models (those using rectangular shapes or sine functions with a constant power of 2) in reproducing rainfall extremes.
• RBL7 retains the ability to capture standard rainfall statistics, including mean, variance, covariance, skewness, and wet period proportion, across timescales ranging from 5 minutes to a decade.
• The model achieved these results despite being calibrated solely at hourly and supra-hourly timescales.

Contributions

• Introduction of RBL7, a novel Poisson cluster rainfall model that incorporates variable sinusoidal rain cell shapes, where the sine function's power dynamically adjusts inversely with rain cell duration.
• Demonstrated a significant improvement in accurately reproducing sub-hourly rainfall extremes, addressing a long-standing challenge in stochastic rainfall generation.
• Showed that a model calibrated at coarser timescales (hourly and supra-hourly) can effectively capture fine-scale (sub-hourly) extremes and standard rainfall statistics.

Funding

• Not explicitly mentioned in the provided text.

Citation

@article{Tai2025Accurate,
  author = {Tai, Chi Vuong and Kim, Dongkyun and Onof, Christian and Wang, Li-Pen and Park, Jeongha},
  title = {Accurate reproduction of sub-hourly rainfall extremes in Poisson cluster rainfall models with a variable sinusoidal pulse},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134821},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134821}
}