Evaluating Design Peak Flow Estimation Methods
Author(s)
Date Issued
2026
Type
article
Volume
40
Issue
232
Journal
Abstract
This study evaluates four hydrological approaches, in particular the Rational method, Fuller’s formula, EBA4SUB, and the STORAGE + COSMO4SUB (S + C) model, across five sub-basins of the Gidra River (Slovakia) for return periods (T) of 2–1000 years. In the gauged Píla sub-basin, all methods deviated from official design flows (6–44.5 m³/s), with empirical approaches showing systematic overestimation (e.g., up to 35 m³/s vs. 6 m³/s at T = 2 years), while Fuller’s formula reached up to threefold overestimation at long return periods. The S + C model provided closer agreement, generally within a factor of two. In ungauged basins, peak flows ranged from near 0 to 479 m³/s, with inter-method variability (CV at T = 1000 years) decreasing from 0.65 in small basins to 0.55 in larger ones. Empirical methods displayed largely linear scaling with basin area, which may oversimplify underlying hydrological processes. More physically-based approaches, such as S + C, offer internally consistent results, but require careful calibration and validation.