Events / Media

Data Assimilation Seminar Series

Prof. Masayuki Yokozawa (Oct. 31, 2014, 15:30-)

Affiliation Shizuoka University
Title Evaluating the productivities of major crops at the global scale using process-based crop model
Abstract We are developing a process-based crop model (PRYSBI-2: Process-Based Regional-Scale Yield Simulator with Bayesian Inference), which simulates the year-to-year variation of productivity to environmental change at the global scale, based on the knowledge on physiological and ecological traits of major annual crops (maize, soybean, rice and wheat). The model describes the main processes such as phenology, photosynthesis, respiration and grain-filling, responding to the physical environment and management including solar radiation, temperature, precipitation, humidity, atmospheric CO2 concentration, irrigation, fertilization and so on. We also developed a spatially explicit global dataset of historical yields for maize, soybean, rice and wheat to explore the historical changes in mean, year-to-year variation and annual rate of change in yields for the period 1982--2006. We combined country yield statistics, satellite-derived net primary production and the datasets related to the crop calendar and harvested area in 2000 at a grid size of 1.125 degree. With the dataset we conducted data assimilation to fitting PRYSBI-2 to historical changes in yields. The feature of this model is that the estimated yields are comparable to real yields. In the seminar, let me firstly present the model structure, dataset and calibration methods, then discuss the future collaborations.
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