Ovaj kalkulator slijedi HEC-RAS referentni priručnik u izračunu složenog n za područje prema Chow 1959, str. 136, jednadžba 6-17 (ne 6-18).
Kamena obloga
Koristite kalkulator trapezoidnog kanala prema Manningu za projektiranje kamene obloge. Ovaj kalkulator je više namijenjen prirodnim presjecima.
Errata
Found and fixed 23 August 2026. A segment drawn exactly vertical — two points at the same station, one above the other, which is how a rectangular channel, a box culvert or a retaining wall is drawn — added no wetted perimeter. Results from before that date are too high for any section with a vertical wall: a channel 10 wide and 5 deep was given a wetted perimeter of 10 instead of 20, and flow about 1.6 times the correct value. A sloping bank, however steep, was never affected, and neither was a wall standing above the water. If you used this page on a section with a vertical wall, please run it again.
Provjera brzine
Visoka brzina podrazumijeva visoku specifičnu energiju uslijed raspoloživog pada. Ta energija može se brzo izgubiti na proširenjima, zavojima ili preprekama. Provjerite je li to razumno za dano gradilište.