Unit Peak Discharge (qu) for NRCS (SCS) Rainfall Distribution Types I, IA, II, III Calculator

December 26, 2025

This is my second attempt since the last release on February 16, 2025, when only Type II rainfall distribution was available. The tool has now been enhanced with graphs, a map, and the ability to view all curves (for Types I, IA, II, and III) simultaneously.

Unit Peak Discharge (qu) Calculator

Unit Peak Discharge (qu)

Tip: hover an area to see Type; click to select.
Rainfall Type
Source: NRCS TR-55, Second Edition, June 1986
Show curves
Ia/P ratio
Time of Concentration (Tc)
60 min
(1.00 hours)
qu at Tc = 1.00 hr (Ia/P = 0.3)
292
csm/in
How to citeShow

Author ORCID: 0009-0000-1316-1362

DOI: 10.5281/zenodo.20973425

APA
Chernitsky, I. (2025). Unit Peak Discharge (qu) for NRCS (SCS) Rainfall Distribution Types I, IA, II, III Calculator [Computer software]. Chernitsky.net. https://doi.org/10.5281/zenodo.20973425
IEEE
I. Chernitsky, "Unit Peak Discharge (qu) for NRCS (SCS) Rainfall Distribution Types I, IA, II, III Calculator," Chernitsky.net, 2025. [Online]. Available: https://doi.org/10.5281/zenodo.20973425
BibTeX
@misc{chernitsky2025calculator,
  author       = {Chernitsky, Ilia},
  title        = {Unit Peak Discharge (qu) for NRCS (SCS) Rainfall Distribution Types I, IA, II, III Calculator},
  year         = {2025},
  doi          = {10.5281/zenodo.20973425},
  howpublished = {\url{https://doi.org/10.5281/zenodo.20973425}},
}