calibration and evaluation of orchidee and...
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Calibration and Evaluation of ORCHIDEE and WOFOST models on rainfed and irrigated wheat experimental fields
C. Ottlé1, F. Maignan1, S. Dantec-Nédélec1, A. de Wit2, G. Boulet3, S. Er-Rakki4, L. Jarlan3, S. Khabba4, Z. Lili-Chabaane5, M. Zribi3
(1) Laboratoire des Sciences du Climat et de l’Environnement, Gif-sur-Yvette, France (2) Alterra, Wageningen, Nederland (3) CESBIO, Toulouse, France
(4) UCAM, Marrakech, Maroc (5) INAT, Tunis, Tunisie Contact: [email protected]
WOFOST and ORCHIDEE models
Results on Agdal, Marroco
Results on Ben Salem, Tunisia
Context / Objectives
Contribution of remote sensing
The land surface model ORCHIDEE, part of the IPSL climate model and the WOFOST crop model developed at ALTERRA, were used to simulate water, carbon and energy surface fluxes as well as crop yield, on two instrumented fields covered by wheat: a rainfed crop in BenSalem, Tunisia and an irrigated crop in Agdal, Marocco. The performances and model errors of both models have been analyzed against observations.
Energy budget
1 2
3
4
WOFOST Crop Model
Study sites / Simulations experiments
ORCHIDEE
Terrestrial Biosphere
(ORCHIDEE)
Atmosphere Prescribed or Modeled (LMDZ GCM)
temperature, winds precipitation, pressure radiation, humidity CO2 concentration
sensible and latent heat fluxes, albedo CO2 flux, roughness surface temperature
Vegetation and Soil Carbon Cycle
(STOMATE)
Dt = 1 day
Energy and Water Balances, options Photosynthesis,
Routing
(SECHIBA)
Dt = 30/15 min
Vegetation distribution
Prescribed or Modeled (LPJ DGVM)
Dt = 1 year
vegetation types NPP, biomass litterfall...
LAI, albedo roughness
GPP, soil profiles of temperature and water
IPSL-CM
Coupled
Model
Krinner et al., 2005
Main features of WOFOST and ORCHIDEE models
• Vegetation defined as Plant Functional Types
13 PFT
A mosaic of vegetation in each grid cell
- One Energy budget for the whole grid box
- Fully implicit coupling with the Atmospheric
LMDz model
- Coupled with snow & soil energy budget
• A “big leaf approach”
- Solve the Heat Diffusion Equation ; 7 layers ;
up to 5.5m
- Fully coupled with the calculation of surface
temperature
- “New” 11-layers soil hydrology scheme
• Soil energy and hydrology
- Farquhar & Ball and Berry model
- Budburst based on GDD, soil water...
- Senescence: Based on Leaf age, Temp...
- Carbon allocation (CENTURY model)
• Photosynthesis / Phenology
The simulation
• runs from sowing to maturity in daily time steps
• is based on response of crop to weather (all Prod levels)
• and also to soil moisture conditions (Wat-lim Prod)
Crop Growth is the result from physiological processes
• biomass accumulation
• phenology (crop development stages)
• Crop water supply and water use
Growth: Phenological development crop life cycle: sowing- flowering
maturity – Ageing Tsum driven
Accumulation of biomass in plant organs Light interception
Photosynthesis Respiration
Assimilate partitioning to plant organs
Leaf area dynamics Decay, death of plant organs
Soil Water balance Crop water supply and use
Exchange with atmosphere Rainfall, Transpiration,
Evaporation
Soil water movements Soil water in root zone
Percolation, deep drainage Capillary rise phreatic water,
runoff
Chantier Site Culture Irrigation Période Remarques
Tensift R3 Blé dur Gravitaire 2002-2003 3 parcelles
Merguellil Ben Salem Blé Pluvial 2011-2012
LAI and Yield
Water balance
Financial support: ANR-AMETHYST
- Wheat fields in Merguellil (pluvial) and in
Tensift (irrigated)
-Models forced with local meteorology +
irrigation
-Model standard parameters used ( WOFOST
parameters resulting from previous EU-AGRI
project)
LAI and Yield
Quite good agreement between Orchidee and WOFOST for LAI and biomass
simulations, significant interannual variations of yield potential.
Soil moisture seems to be underestimated with ORCHIDEE, min and max values of soil water content need adjustement to better fit the data
Conclusions: Preliminary simulations of WOFOST and ORCHIDEE models have been performed on wheat fields (pluvial and irrigated ). Results show good agreement with the observations. Calibration of biomass require further calibration. Then, the models will be able to perform simulations under future climate scenarios to assess future evolution of surface fluxes and water requirements.
Minimal and maximal values of modeled soil water content need adjustement to better fit the data, but time variations are well represented.
LAI observed in 2012, correctly simulated by both ORCHIDEE and WOFOST Interannual variability simulated, validation needed
Total Above Ground Biomass require calibration against observations
Energy budget
Water balance