EPIC - crop.cyield¶

class mef_agri.models.crop.cyield.model_epic.Yield(**kwargs)¶

Simplified yield model which uses only equations 15, 16 and 17 from [R2] to compute yield biomass. If water stress should be considered (i.e. equations 62 and 63 should be incorporated in yield biomass computation), see Yield_Stressed.

kwargs \(\rightarrow\) see mef_agri.models.base.Model

biomass()¶

MQ - Random Output

\(c_{\textrm{Y-bm},k}\ [\frac{t}{ha}]\) - [R2] (equ. 15)

Returns:: yield biomass
Return type:: numpy.ndarray

bmag()¶

RQ - 'biomass_aboveground' from model with id 'crop'

\(c_{\textrm{bma},k}\ [\frac{t}{ha}]\)

Returns:: aboveground biomass
Return type:: Requirement

harvest_index()¶

MQ - Random Output

\(c_{\textrm{Y-hi},k}\ [\ ]\) - [R2] (equ. 16)

[R2] is not totally clear about this quantity, i.e. the time-variable harvest index. It is computed with equ. 16 but in equ. 15, the harvest index at maturity harvest_index_mat() is used to compute biomass. In this case, the time-variable harvest index would not be used at all. Thus, here it will be used in equ. 15 to compute biomass.

Returns:: harvest index
Return type:: numpy.ndarray

harvest_index_max()¶

MQ - Hyper-Parameter

\(y_{\textrm{hi-max},0}\ [\ ]\) - [1] (equ. 16, table 2)

Returns:: max. attainable harvest index of crop
Return type:: numpy.ndarray

heat_unit_factor()¶

MQ - Random Output

\(c_{\textrm{Y-huf},k}\ [\ ]\) - [R2] (equ. 17)

Returns:: heat unit factor for yield/harvest index
Return type:: numpy.ndarray

hui()¶

RQ - 'heat_unit_index' from model with id 'crop.development'

\(c_{\textrm{D-hui},k}\ [\ ]\)

Returns:: current heat unit index
Return type:: Requirement

initialize(epoch)¶

Initialization of random outputs with zero vectors

Parameters:: epoch (datetime.date) – initialization epoch

update(epoch)¶

The following computations are performed

if self.wdorm.value == True
- heat_unit_factor() set to zero vector
- harvest_index() and biomass() remain unchanged
else

Parameters:: epoch (datetime.date) – current evaluation epoch

wdorm()¶

RQ - 'winter_dormancy' from model with id 'crop.development'

\(c_{\textrm{D-wd},k}\ [\ ]\) (boolean value)

Returns:: indicator for winter dormancy period
Return type:: Requirement

class mef_agri.models.crop.cyield.model_epic.Yield_Stressed(**kwargs)¶

Yield model wich considers water stress in the harvest-index-computation - i.e. incorporating equations 62 and 63 from [R2] .

harvest_index()¶

MQ - Random Output

\(c_{\textrm{Y-hi},k}\ [\ ]\) - [R2] (equ. 62)

Returns:: harvest index
Return type:: numpy.ndarray

heat_unit_factor()¶

MQ - Random Output

\(c_{\textrm{Y-huf},k}\ [\ ]\) - [R2] (equ. 63)

Returns:: heat unit factor for yield/harvest index
Return type:: numpy.ndarray

update(epoch)¶

The following computations are performed

heat_unit_factor()
harvest_index()
Yield.biomass()

Parameters:: epoch (datetime.date) – current evaluation epoch

water_stress_influence()¶

MQ - Hyper-Parameter

\(c_{\textrm{Y-ws},0}\ [\ ]\) - [R2] (equ. 62, table 2)

Returns:: crop specific water stress influence factor on yield
Return type:: numpy.ndarray

wstrs()¶

RQ - 'water_stress' from model with id 'crop.stress'

\(c_{\textrm{W-str},k}\ [\ ]\)

Returns:: water stress indicator
Return type:: Requirement