VIC模型中用到的每种植被类型的植被参数均在该文件中以ASCII文件的列格式提供。不同的植被类型参数,vegetation parameter file提供了每个网格单元的植被类型数量和它们的面积占比。文件的顶部可以加入以#开头的标题。也可以在植被库文件的每行结尾加入注释。
Vegetation Library File Format
Variable Name |
Units |
Number of Values |
Description |
veg_class |
N/A |
1 |
Vegetation class identification number (reference index for library table) |
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]) |
rarc |
s/m |
1 |
Architectural resistance of vegetation type (~2 s/m) |
rmin |
s/m |
1 |
Minimum stomatal resistance of vegetation type (~100 s/m) |
LAI |
fraction |
12 |
Leaf-area index of vegetation type |
FCANOPY (Only present if VEGLIB_FCAN=TRUE in global parameter file |
fraction |
12 |
Partial vegetation cover fraction |
albedo |
fraction |
12 |
Shortwave albedo for vegetation type |
rough |
m |
12 |
Vegetation roughness length (typically |
displacement |
m |
12 |
Vegetation displacement height (typically |
wind_h |
m |
1 |
Height at which wind speed is measured. If using snow interception routines please read the documentation on wind_h. |
RGL |
W/m2 |
1 |
Minimum incoming shortwave radiation at which there will be transpiration. For trees this is about 30 W/m2, for crops about 100 W/m2. |
rad_atten |
fract |
1 |
Radiation attenuation factor. Normally set to 0.5, though may need to be adjusted for high latitudes. |
wind_atten |
fract |
1 |
Wind speed attenuation through the overstory. The default value has been 0.5. |
trunk_ratio |
fract |
1 |
Ratio of total tree height that is trunk (no branches). The default value has been 0.2. |
Ctype (Only present if VEGLIB_PHOTO=TRUE in global parameter file |
0 or 1 (0 = C3, 1 = C4) |
1 |
Photosynthetic pathway (NOTE: the previous input values of "C3" and "C4" are still accepted but are deprecated. |
MaxCarboxRate (Only present if VEGLIB_PHOTO=TRUE in global parameter file |
mol CO2/m2s |
1 |
Maximum carboxlyation rate at 25 deg C |
MaxETransport (C3) or CO2Specificity (C4) (Only present if VEGLIB_PHOTO=TRUE in global parameter file |
mol CO2/m2s |
1 |
Maximum electron transport rate at 25 deg C (C3) or CO2 specificity at 25 deg C (C4) |
LightUseEff (Only present if VEGLIB_PHOTO=TRUE in global parameter file |
mol CO2/mol photons |
1 |
Light-use efficiency |
NscaleFlag (Only present if VEGLIB_PHOTO=TRUE in global parameter file |
0 or 1 |
1 |
1 = nitrogen-scaling factors are applicable to this veg class |
Wnpp_inhib (Only present if VEGLIB_PHOTO=TRUE in global parameter file |
fract |
1 |
Fraction of maximum moisture storage in top soil layer above which photosynthesis begins to be inhibited by wet conditions |
NPPfactor_sat (Only present if VEGLIB_PHOTO=TRUE in global parameter file |
fract |
1 |
Ratio of NPP under saturated conditions (moisture fraction = 1.0) to NPP at moisture fraction = Wnpp_inhib |
comment |
N/A |
1 |
Comment block for vegetation type. Model skips end of line so spaces are valid entries. |
植被库文件示例
#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 trunk_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