Difference between revisions of "Module Vegetation"
From MohidWiki
Davidbrito (talk | contribs) (→Overview) |
Davidbrito (talk | contribs) (→Overview) |
||
| Line 2: | Line 2: | ||
Vegetation Model handles information about vegetation cover and interacts with atmosphere and soil properties. | Vegetation Model handles information about vegetation cover and interacts with atmosphere and soil properties. | ||
Vegetation dynamics can be handled by the model in two different manners: i) reading from file (time serie, hdf, grid); ii) using a vegetation growth model. | Vegetation dynamics can be handled by the model in two different manners: i) reading from file (time serie, hdf, grid); ii) using a vegetation growth model. | ||
| − | The first option is the previous formulation where LAI and root depth properties are provided by user and water uptake is simulated. The second option uses a SWAT based vegetation growth model and plant biomass, LAI, nutrient content and | + | The first option is the previous formulation where LAI and root depth properties are provided by user and water uptake is simulated. The second option uses a SWAT based vegetation growth model and plant biomass, LAI, nutrient content and nutrient uptake are explicitly simulated. |
SWAT vegetation growth model uses the concepts from EPIC crop model (Izaurralde et al., 2006) of radiation-use efficiency by which a fraction of daily photosynthetically active radiation is intercepted by the plant canopy and converted into plant biomass. Gains in plant biomass are affected by vapor pressure deficits and atmospheric CO2 concentration. Stress indices for water, temperature, nitrogen, phosphorus and aeration are calculated using the value of the most severe of these stresses to reduce potential plant growth and crop yield. Nutrient uptake is done based on plant target (optimal content) and availability in soil. | SWAT vegetation growth model uses the concepts from EPIC crop model (Izaurralde et al., 2006) of radiation-use efficiency by which a fraction of daily photosynthetically active radiation is intercepted by the plant canopy and converted into plant biomass. Gains in plant biomass are affected by vapor pressure deficits and atmospheric CO2 concentration. Stress indices for water, temperature, nitrogen, phosphorus and aeration are calculated using the value of the most severe of these stresses to reduce potential plant growth and crop yield. Nutrient uptake is done based on plant target (optimal content) and availability in soil. | ||
Revision as of 10:51, 13 February 2009
Contents
Overview
Vegetation Model handles information about vegetation cover and interacts with atmosphere and soil properties. Vegetation dynamics can be handled by the model in two different manners: i) reading from file (time serie, hdf, grid); ii) using a vegetation growth model. The first option is the previous formulation where LAI and root depth properties are provided by user and water uptake is simulated. The second option uses a SWAT based vegetation growth model and plant biomass, LAI, nutrient content and nutrient uptake are explicitly simulated.
SWAT vegetation growth model uses the concepts from EPIC crop model (Izaurralde et al., 2006) of radiation-use efficiency by which a fraction of daily photosynthetically active radiation is intercepted by the plant canopy and converted into plant biomass. Gains in plant biomass are affected by vapor pressure deficits and atmospheric CO2 concentration. Stress indices for water, temperature, nitrogen, phosphorus and aeration are calculated using the value of the most severe of these stresses to reduce potential plant growth and crop yield. Nutrient uptake is done based on plant target (optimal content) and availability in soil.
Concepts
Property
See the list of allowed properties names
Main processes
Other Features
Outputs
Time series
Box integration
Maps (HDF5 format)
To write 3D results use keyword OUTPUT_TIME and define keyword:
OUTPUT_HDF : 1
in each property that you whish to write results.
To write results only in the surface use keyword SURFACE_OUTPUT_TIME and define keyword:
OUTPUT_SURFACE_HDF : 1
in each property that you which to write results. Surface results can be written with a different frequency than the normal 3D maps.
Statistics
References
Some keywords/properties od the input file vegetation_x.dat are:
<beginvegetationtype>
ID : 1 NAME : Sample vegetation type
<<begin_property>> !total leaf are / projected crown area PROPERTY_NAME : leaf area index IS_CONSTANT : 1 CONSTANT_VALUE : 0 <<end_property>>
<<begin_property>> !the depth of water that can be retained by leaves of a particular species per unit leaf area PROPERTY_NAME : specific leaf storage IS_CONSTANT : 1 CONSTANT_VALUE : 0 <<end_property>>
<<begin_property>> !factor for lowering evapotranspiration due to the crop type based on a reference evapotranspiration PROPERTY_NAME : evtp crop coefficient IS_CONSTANT : 1 CONSTANT_VALUE : 1 <<end_property>>
<<begin_property>> !self declaring... PROPERTY_NAME : root depth IS_CONSTANT : 1 CONSTANT_VALUE : 0 <<end_property>>
<<begin_property>> !Parameter of the root water uptake model after FEDDES (1978): 'Simulation of field water use and crop yield' PROPERTY_NAME : feddes h1 IS_CONSTANT : 1 CONSTANT_VALUE : -0.1 <<end_property>>
<<begin_property>> !Parameter of the root water uptake model after FEDDES (1978): 'Simulation of field water use and crop yield' PROPERTY_NAME : feddes h2 IS_CONSTANT : 1 CONSTANT_VALUE : -0.25 <<end_property>>
<<begin_property>> !Parameter of the root water uptake model after FEDDES (1978): 'Simulation of field water use and crop yield' PROPERTY_NAME : feddes h3 IS_CONSTANT : 1 CONSTANT_VALUE : -5.0 <<end_property>>
<<begin_property>> !Parameter of the root water uptake model after FEDDES (1978): 'Simulation of field water use and crop yield' !Wilting point PROPERTY_NAME : feddes h4 IS_CONSTANT : 1 CONSTANT_VALUE : -80.0 <<end_property>>
<<begin_property>> !self declaring... PROPERTY_NAME : permeable fraction IS_CONSTANT : 1 CONSTANT_VALUE : 1.0 <<end_property>>
<endvegetationtype>
