Data Sources

Default Lookup Values Sources:

Curve Number Generator (CONUS) (NLCD & SSURGO)

Most but not all of the default values of CN have come from the following draft document by USDA.

https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=41606.wba Table 9A-1 page 27

Backup Link for the document:

https://drive.google.com/file/d/1b6IxeANRyEem-oGcvRC6WThKPxBz1R9C/view?usp=sharing

Forest CN values are derived from Woods value from National Engineering Handbook Part 630. Evergreen forest is assumed to retain more water than Deciduous.

https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17758.wba Table 9-1 page 9-3

Curve Number Generator (GLOBAL) (ESA & ISRIC)