Evergreen Trees

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4.3.11. Evergreen Trees#

Properties for evergreen trees and shrubs.

Evergreen vegetation maintains foliage year-round, providing consistent evapotranspiration and shading. Common in urban parks and residential areas, these surfaces have relatively low albedo and high roughness lengths.

Parameters:

sfr#

Surface fraction of grid area covered by this surface type

Unit:

dimensionless

Example:

0.14285714285714285

emis#

Surface emissivity for longwave radiation

Unit:

dimensionless

Example:

0.95

ohm_threshsw#

Summer/winter threshold based on temperature for OHM calculation

Unit:

degC

Example:

0.0

ohm_threshwd#

Soil moisture threshold determining whether wet/dry OHM coefficients are applied

Unit:

dimensionless

Example:

0.0

ohm_coef#

The ohm_coef parameter group is defined by the Seasonal/Wetness OHM Coefficients structure.

soildepth#

Depth of soil layer for hydrological calculations

Unit:

mm

Default:

None (optional)

soilstorecap#

Maximum water storage capacity of soil

Unit:

mm

Default:

None (optional)

statelimit#

Minimum water storage capacity for state change

Unit:

mm

Example:

10.0

wetthresh#

Surface wetness threshold for OHM calculations

Unit:

dimensionless

Example:

0.5

sathydraulicconduct#

Saturated hydraulic conductivity of soil

Unit:

mm s-1

Default:

None (optional)

waterdist#

Water distribution for evergreen trees

The waterdist parameter group is defined by the Water Distribution structure.

storedrainprm#

Storage and drain parameters

The storedrainprm parameter group is defined by the Drainage Parameters structure.

snowpacklimit#

Limit of snow that can be held on surface

Unit:

mm

Example:

10.0

thermal_layers#

Thermal layers for the surface

The thermal_layers parameter group is defined by the Thermal Layers structure.

irrfrac#

Fraction of surface area that can be irrigated

Unit:

dimensionless

Example:

0.0

ref#

The ref parameter group is defined by the Reference Info structure.

alb#

Albedo

Unit:

dimensionless

Example:

0.2

alb_min#

Minimum albedo

Unit:

dimensionless

Example:

0.2

alb_max#

Maximum albedo

Unit:

dimensionless

Example:

0.3

beta_bioco2#

Biogenic CO2 exchange coefficient

Unit:

dimensionless

Default:

None (optional)

beta_enh_bioco2#

Enhanced biogenic CO2 exchange coefficient

Unit:

dimensionless

Example:

0.7

alpha_bioco2#

Biogenic CO2 exchange coefficient

Unit:

dimensionless

Default:

None (optional)

alpha_enh_bioco2#

Enhanced biogenic CO2 exchange coefficient

Unit:

dimensionless

Example:

0.9

resp_a#

Respiration coefficient

Unit:

umol m-2 s-1

Default:

None (optional)

resp_b#

Respiration coefficient

Unit:

dimensionless

Default:

None (optional)

theta_bioco2#

Biogenic CO2 exchange coefficient

Unit:

dimensionless

Default:

None (optional)

maxconductance#

Maximum surface conductance

Unit:

mm s-1

Example:

0.5

min_res_bioco2#

Minimum respiratory biogenic CO2

Unit:

umol m-2 s-1

Example:

0.1

lai#

Leaf area index parameters

The lai parameter group is defined by the LAI structure.

ie_a#

Irrigation efficiency coefficient-automatic

Unit:

dimensionless

Example:

0.5

ie_m#

Irrigation efficiency coefficient-manual

Unit:

dimensionless

Example:

0.6

faievetree#

Frontal area index of evergreen trees

Unit:

dimensionless

Default:

None (optional)

evetreeh#

Evergreen tree height

Unit:

m

Default:

None (optional)