Simulation of evapotranspiration and carbon dioxide flux in the wheat-maize rotation croplands of the North China Plain using the Simple Biosphere Model

• Published in: Hydrological processes 2011-09, Vol.25 (20), p.3107-3120
• Main Authors: Lei, Huimin, Yang, Dawen, Shen, Yanjun, Liu, Yu, Zhang, Yucui
• Format: Article
• Language: English
• Subjects: Carbon dioxide; China; Computer simulation; eddy covariance technique; Evapotranspiration; Flux; Fluxes; Land; land surface model; latent heat flux; Mathematical models; net ecosystem exchange
• ISSN: 0885-6087; 1099-1085; 1099-1085
• DOI: 10.1002/hyp.8026

The North China Plain, which is critical for food production in China, is encountering serious water shortage due to heavy agricultural water requirement. The accurate modelling of carbon dioxide flux and evapotranspiration (ET) in croplands is thus essential for yield prediction and water resources management. The land surface model is powerful in simulating energy and carbon dioxide fluxes between land and atmosphere. Some key processes in the Simple Biosphere Model (Version 2, SiB2) were parameterized based on the observations. The simulated fluxes were tested against the eddy covariance flux measurements over two typical winter wheat/maize double cropping fields. A simple diagnostic parameterisation of soil respiration, not included in SiB2, was added and calibrated using the observations to model the carbon budget. The Ball‐Berry stomatal conductance model was calibrated using observed leaf gas exchange rate, showing that the original SiB2 could significantly underpredict the ET in the wheat field. SiB2 significantly underpredicted soil resistance at the Weishan site, leading to overpredict the ET. Overall, there was a close agreement between the simulated and observed latent heat fluxes and net CO2 exchange using the re‐parameterized SiB2. These findings are important when the model is used for the regional simulation in the North China Plain. Copyright © 2011 John Wiley & Sons, Ltd.