Coupling land surface and crop growth models for predicting evapotranspiration and carbon exchange in wheat-maize rotation croplands

摘要

The North China Plain is one of the key crop-producing regions in China.However, water resources in the area are limited. Accurate modeling of waterconsumption and crop production in response to the changing environment isimportant. To describe the two-way interactions among climate, irrigation,and crop growth better, the modified crop phenology and physiology schemefrom the SiBcrop model was coupled with the second version of the SimpleBiosphere model (SiB2) to simulate crop phenology, crop production, andevapotranspiration of winter wheat and summer maize, which are two of themain crops in the region. In the coupled model, the leaf area index (LAI)produced by the crop phenology and physiology scheme was used in estimatingsub-hourly energy and carbon fluxes. Observations obtained from two typicaleddy covariance sites located in this region were used to validate themodel. The coupled model was able to accurately simulate carbon and energyfluxes, soil water content, biomass carbon, and crop yield, especially forlatent heat flux and carbon flux. The LAI was also well simulated by themodel. Therefore, the coupled model is capable of assessing the responses ofwater resources and crop production to the changes of future climate andirrigation schedules of this region.