4.20 - Penman-Monteith Crop Coefficient File (*.kpm)

The crop coefficient file (*.kpm) contains Penman-Monteith crop coefficient curves, as defined in ASCE-70. The same crop coefficient curves are used for the Penman-Monteith and the ASCE Standardized Penman-Monteith methods. This file is read when flag1= 3 or 5 in the model control file (see Section 4.4). The recommended naming convention to identify crops with their crop coefficients is Crop_Name.XXX as described in Section 3.1.7. An example is provided in Appendix A.

Row-Data Program Variable Description
Row 1 Format (a80)
1-1 remark Title
Row 2 Free Format
2-1 nc Number of crop coefficient curves
3-1 id Crop number (not used in StateCU)
3-2 cropn Crop name
4-1 kcday(1,j) Time from start of growth to effective cover (%) or number of days after effective cover
4-2 kcb(1,j) Corresponding crop coefficient for alfalfa-based ET, for crop j

Read 33 day/crop coefficient pairs (Row 4) for alfalfa

Read 11 day/crop coefficient pairs (Row 4) for grass pasture

Read 22 day/crop coefficient pairs (Row 4) for all other crop types

Repeat for the number of crop coefficient curves, nc