Park et al. (2026) A copula-based stochastic simulation method for the penman wind function (PWF) in in-stream evaporation

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-08-23
• Authors: Minwoo Park, Ghani Rahman, Joo‐Heon Lee, Hyun‐Han Kwon
• DOI: 10.1016/j.jhydrol.2026.136279

Research Groups

• Department of Civil Engineering, University of Seoul, Seoul, the Republic of Korea
• Department of Geography, University of Gujrat, Punjab, Pakistan
• Department of Civil Engineering, Joongbu University, Goyang-si, the Republic of Korea

Short Summary

This study introduces a copula-based stochastic simulation method for the Penman Wind Function (PWF) in in-stream evaporation. The proposed framework combines site-specific calibration with empirical-prior-based uncertainty propagation to quantify uncertainty in in-stream evaporation estimates under data-limited conditions.

Objective

• Evaluate the usefulness of site-specific PWF calibration where high-resolution observations are available.
• Quantify uncertainty, bias, and empirical support when reservoir-derived or literature-informed coefficients are used under data-limited conditions.

Study Configuration

• Spatial Scale: Local to regional scale in South Korea.
• Temporal Scale: Short-term (days) to long-term (years).

Methodology and Data

• Models used: Penman Wind Function (PWF).
• Data sources: High-resolution flux measurements from the Andong Stream Experiment Center, evaporation observations at the Yongdam Dam Reservoir, and literature-derived coefficient pairs.

Main Results

• Site-specific calibration of PWF coefficients using high-resolution flux measurements produced reliable estimates (r = 0.862, CoE = 0.731, RMSE = 1.500 mm/day).
• Literature-derived coefficient pairs exhibited substantial variability in their empirical support.
• Copula-based Monte Carlo simulation showed that dependence among literature-derived coefficients was weak.

Contributions

• This study provides a framework for uncertainty-aware baseline estimation of in-stream evaporation under data-limited conditions.
• The proposed method combines site-specific calibration with empirical-prior-based uncertainty propagation to quantify uncertainty and bias in in-stream evaporation estimates.

Funding

• This research was supported by the Korea Institute of Civil Engineering and Building Technology (KICT) and the National Research Foundation of Korea (NRF).

Citation

@article{Park2026copulabased,
  author = {Park, Minwoo and Rahman, Ghani and Lee, Joo‐Heon and Kwon, Hyun‐Han},
  title = {A copula-based stochastic simulation method for the penman wind function (PWF) in in-stream evaporation},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136279},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136279}
}