Preprints
https://doi.org/10.5194/egusphere-2025-4268
https://doi.org/10.5194/egusphere-2025-4268
23 Sep 2025
 | 23 Sep 2025
Status: this preprint is open for discussion and under review for Hydrology and Earth System Sciences (HESS).

Polynomial depth-duration-frequency curves

Miloslav Müller, Lenka Crhová, Filip Hulec, and Marek Kašpar

Abstract. Depth-duration-frequency (DDF) curves depict how much precipitation occurs on average in a given location during various time intervals once in a given return period. The standard approach to the construction of these curves assumes that the parameters governing the scaling behaviour of rainfall intensity with duration remain constant. We show that in regions where different meteorological processes control short- and long-duration extreme precipitation events, this approach is applicable only in limited time intervals. If the range is as wide as several minutes to several days, three parameters are not sufficient for representing the complexity of the DDF curve shapes. In fact, the curves are wave-shaped because convective and cyclonic precipitation occur for limited lengths of up to several hours and several days, respectively. Thus, we suggest applying polynomial functions of the sixth degree to generate smooth DDF curves that fit design precipitation totals for individual time intervals. Nevertheless, return values need to be fitted against logarithmic time intervals instead of only time. These polynomial DDF curves suitably represent extreme precipitation statistics even in orographically influenced locations where already the precipitation maxima of several hours can be caused by cyclonic precipitation events.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.
Share
Miloslav Müller, Lenka Crhová, Filip Hulec, and Marek Kašpar

Status: open (until 08 Nov 2025)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
Miloslav Müller, Lenka Crhová, Filip Hulec, and Marek Kašpar
Miloslav Müller, Lenka Crhová, Filip Hulec, and Marek Kašpar

Viewed

Total article views: 762 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
745 13 4 762 3 6
  • HTML: 745
  • PDF: 13
  • XML: 4
  • Total: 762
  • BibTeX: 3
  • EndNote: 6
Views and downloads (calculated since 23 Sep 2025)
Cumulative views and downloads (calculated since 23 Sep 2025)

Viewed (geographical distribution)

Total article views: 762 (including HTML, PDF, and XML) Thereof 762 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 02 Oct 2025
Download
Short summary
Rainfall amount of a given probability increases with increasing rainfall duration. However, we found out that in a region where extreme short-term and long-lasting rainfalls are due to different mechanisms, this increase can be “wave-shaped”. The curves describing the increase rise faster in two sections, namely on the order of tens of minutes and several tens of hours, which are typical durations of precipitation associated with thunderstorms and extratropical cyclones, respectively.
Share