Runoff Curve Number

Written by Jerry Ratzlaff on . Posted in Geotechnical Engineering

Runoff curve number, abbreviated as CN, a dimensionless number, is the water flow that occurs when the soil is infiltrated to full capacity and excess water or rain.

 

Runoff Curve Number Formula

\(\large{ CN = \frac{ 1000 }{ S \;+\; 10 }  }\) 
Symbol English Metric
\(\large{ CN }\) = runoff curve number \(\large{dimensionless}\)
\(\large{ S } \) = the potential maximum soil moisture retention after runoff begins \(\large{lbf}\) \(\large{N}\)

 

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Tags: Soil Equations