Implements FAO 56 - Purdue...

Implements FAO 56 ◦ http://www.fao.org/docrep/X0490E/x0490e00.htm

◦ Implements dual crop coefficient: Kc = Kcb + Ke

Replaces WEPP Penman Equation

Activated by having a file called: pmetpara.txt

File must be in the same directory as other WEPP input files. (runs subdirectory)

No user interface support, file must be created in a text editor and matched to the management file.

Line 1: number of records in file

Line 2: 5 values ◦ a) crop name (character(8))

◦ b) mid-season crop coefficient for Penman-Montieth dual coefficient method

◦ c) coefficient p for readily available root zone water formula

◦ d) line number

◦ e) comment

Line 2 is repeated for the number of records on line 1.

Mid-Season Crop Coefficient ◦ See Table 12 in FAO 56

Coefficient p for soil water depletion fraction for no stress ◦ See Table 22 in FAO 56

1

Tre_3082,0.71,0.75,0,Mature forest

Name from WEPP management file

Mid-season crop coefficient

Coefficient p for readily available water

• First look at the management output file from a WEPP run and find the names of the plants. • This is the name in the first column of the pmetpara.txt file.

S. Dun. 2013 Applying online WEPP to assess forest watershed hydrology. Trans. ASABE Special Collection from 2011 Erosion Symposium.