Vegetation Library File
Vegetation parameters needed for each vegetation type used in the VIC model are provided in a column format ASCII file as described in this document. Parameters are given for different vegetation types, and are referenced by the vegetation parameter file, which provides information about the number of vegetation types per grid cell, and their fractional coverage. A header may be added to the top of the file if the first column contains a '#'. Comments can also be added to the end of each line in the vegetation library file.
The following icons are used to identify changes between version 3.2.1 and 4.0 in the documentation:
Column |
Variable Name |
Units |
Number of Values |
Description |
|
1 |
veg_class |
N/A |
1 |
Vegetation class identification number (reference index for library table) |
|
2 |
overstory |
N/A |
1 |
Flag to indicate whether or not the current vegetation type has an overstory (TRUE for overstory present [e.g. trees], FALSE for overstory not present [e.g. grass]) |
|
3 |
rarc |
s/m |
1 |
Architectural resistance of vegetation type (~2 s/m) |
|
4 |
rmin |
s/m |
1 |
Minimum stomatal resistance of vegetation type (~100 s/m) |
|
5 : 16 |
LAI |
|
12 |
Leaf-area index of vegetation type |
|
17 : 28 |
albedo |
fraction |
12 |
Shortwave albedo for vegetation type |
|
29 : 40 |
rough |
m |
12 |
Vegetation roughness length (typically 0.123 * vegetation height) |
|
41 : 52 |
displacement |
m |
12 |
Vegetation displacement height (typically 0.67 * vegetation height) |
|
53 |
m |
1 |
Height at which wind speed is measured. If using snow interception routines please read information page |
|
|
54 |
RGL |
W/m^2 |
1 |
Minimum incoming shortwave radiation at which there will be transpiration. For trees this is about 30 W/m^2, for crops about 100 W/m^2. |
|
55 |
rad_atten |
fract |
1 |
Radiation attenuation factor. Normally set to 0.5, though may need to be adjusted for high latitudes. |
|
56 |
wind_atten |
fract |
1 |
Wind speed attenuation through the overstory. The default value has been 0.5. |
|
57 |
trunk_ratio |
fract |
1 |
Ratio of total tree height that is trunk (no branches). The default value has been 0.2. |
|
58 |
comment |
N/A |
1 |
Comment block for vegetation type. Model skips end of line so spaces are valid entrys. |
Vegetation parameters for agricultural region
#Class OvrStry Rarc Rmin JAN-LAI FEB-LAI MAR-LAI APR-LAI MAY-LAI JUN-LAI JUL-LAI AUG-LAI SEP-LAI OCT-LAI NOV-LAI DEC-LAI JAN-ALB FEB_ALB MAR-ALB APR-ALB MAY-ALB JUN-ALB JUL-ALB AUG-ALB SEP-ALB OCT-ALB NOV-ALB DEC-ALB JAN-ROU FEB-ROU MAR-ROU APR-ROU MAY-ROU JUN-ROU JUL-ROU AUG-ROU SEP-ROU OCT-ROU NOV-ROU DEC-ROU JAN-DIS FEB-DIS MAR-DIS APR-DIS MAY-DIS JUN-DIS JUL-DIS AUG-DIS SEP-DIS OCT-DIS NOV-DIS DEC-DIS WIND_H RGL rad_atten wind_atten truck_ratio COMMENT
2 0 25.0 220. 0.000 0.000 0.000 0.000 1.000 2.500 4.000 4.500 0.500 0.000 0.000 0.000 0.10 0.10 0.10 0.10 0.20 0.20 0.20 0.20 0.20 0.10 0.10 0.10 0 0 0 0 0.0615 0.123 0.246 0.3075 0.3075 0 0 0 0 0 0 0 0.335 0.67 1.34 1.675 1.675 0 0 0 2.0 100 0.5 0.5 0.2 Corn Field
3 0 25.0 220. 0.000 0.000 0.000 0.000 1.000 3.000 5.000 6.000 3.000 0.000 0.000 0.000 0.10 0.10 0.10 0.10 0.20 0.20 0.20 0.20 0.20 0.10 0.10 0.10 0 0 0 0 0.03075 0.0615 0.09225 0.09225 0.09225 0 0 0 0 0 0 0 0.1675 0.335 0.5025 0.5025 0.5025 0 0 0 2. 100 0.5 0.5 0.2 Soy Field
VIC Administrator
Last modified: Fri May 12 14:29:55 PDT 2000