Meaning of value Land_Use Index, vegfra

[Adi Riyanto]

Can you help me about the meaning of the value of these variables?
lu_index in my Grads results 1-18
What does it mean that the numbers 1 to 18?
and then i display the variable of vegfra
displays the results of 52 455, 44 343 and others
whether the meaning of these figures shows that the amount of land area covered by vegetation? if yes what is the unit?
if not what the real meaning of these figures?

[cxiao]

LU_INDEX: Land use
For the meaning of each catogory, please see
http://www.mmm.ucar.edu/wrf/users/docs/ ... nd_Use_and

VEGFRA: VEGETATION FRACTION (%)