Changes between Version 1 and Version 2 of DevelopmentActivities/ORCHIDEE-hydraulicArch


Ignore:
Timestamp:
10/09/21 15:52:18 (4 months ago)
Author:
peylin
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • DevelopmentActivities/ORCHIDEE-hydraulicArch

    v1 v2  
    66 - Understand the differences between both models ; 
    77 - Prepare a strategy in order to implement only one “mixed” model in ORCHIDEE_trunk. 
    8 The meeting was organised around the presentation of the two models (see slides for more details) and the discussion on the advantages/drawbacks of each model. 
     8 
     9The meeting was organised around the presentation of the two models and the discussion on the advantages/drawbacks of each model: 
     10 - [attachment:Yitong_ORCHIDEE-CAN_7_Oct_2021.pdf Yitong presentation] 
     11 - [attachment:Julien_Présentation.pdf Julien presentation] 
     12 
    913Summary of the differences: 
    10 Model   YItong’s        Julien’s 
    11 Starting point  Emilie Joetzjer’s previous version of the hydraulic architecture in the module hydraulic_arch.f90. 
    12  
    13 This previous version was more a proof about the necessity of introducing and hydraulic architecture than a properly implemented model as ORCHIDEE would need.  New model based on ORCHIDEE_trunk version of May 2020. 
    14  
    15 The model does not rely on the previous work on the hydraulic architecture. It is composed by new subroutines introduced in hydrol module. 
    16 Overall scheme  Both scheme rely on the description of the water transport from soil/root interface towards leaves thanks to a resistance/capacitance scheme. 
    17 Root absorption Rely on a development by Emily which, in addition to a soil/root resistance based on soil conductivity and root biomass, adds a weighting of the absorption according to the amount of water present in each layer. The idea is to weight more by the amount of water than by the root biomass. Two ways to model root absorption: 
    18 -       Radial resolution of Richards’ equation around a fictive root which have the length of the total amount of roots in each layer; 
    19 -       Classic root absorption scheme relying on a dynamic resistance 
    20 Transport through canopy        Resistances : 
    21 Dynamic resistances linked to the water potential at each stage 
    22  
    23 Capacitances : 
    24 Fixed values.   Resistances : 
    25 Fixed values. 
    26  
    27 Capacitances : 
    28 Dynamic values linked to the water potential of each storage pool. 
    29 Stomatal conductance    Two decoupled stomatal conductances for assimilation and water control. Only the one that controls water is linked to leaf water potential      One stomatal conductance calculated thanks to the leaf water potential. The conductance controls assimilation and water supply. 
     14 - Starting point 
     15   - Yitong: Emilie Joetzjer’s previous version of the hydraulic architecture in the module hydraulic_arch.f90. This previous version was more a proof about the necessity of introducing and hydraulic architecture than a clean implemented model as ORCHIDEE would need.  
     16   - Julien: New model based on ORCHIDEE_trunk version of May 2020. New subroutines introduced in hydrol module. 
     17 - Overall scheme: Both scheme rely on the description of the water transport from soil/root interface towards leaves thanks to a resistance/capacitance scheme. 
     18 - Root absorption 
     19  - Yitong: Rely on a development by Emily which, in addition to a soil/root resistance based on soil conductivity and root biomass, adds a weighting of the absorption according to the amount of water present in each layer. The idea is to weight more by the amount of water than by the root biomass.      
     20  - Julien: Two ways to model root absorption: 
     21   - Radial resolution of Richards’ equation around a fictive root which have the length of the total amount of roots in each layer; 
     22   - Classic root absorption scheme relying on a dynamic resistance  
     23 - Transport through canopy      
     24  - Resistances : 
     25   - Yitong: Dynamic resistances linked to the water potential at each stage 
     26   - Julien: fixed resistances 
     27  - Capacitances : 
     28   - Yitong: fixed values 
     29   - Julien: Dynamic values linked to the water potential of each storage pool. 
     30 - Stomatal conductance T 
     31wo decoupled stomatal conductances for assimilation and water control. Only the one that controls water is linked to leaf water potential       One stomatal conductance calculated thanks to the leaf water potential. The conductance controls assimilation and water supply. 
    3032Resolution method       Global method: 
    3133The scheme calculates transpiration demand and supply. If the supply does not reach the demand, energy budget is recalculated (mleb has to iterate to converge towards the supply).