The impacts of data constraints on the predictive performance of a
general process-based crop model (PeakN-crop v1.0)
Silvia Caldararu1,a, Drew W. Purves1, and Matthew J. Smith11Microsoft Research, Cambridge, UK aNow at Max Planck Institute for Biogeochemistry, Jena, Germany
Received: 17 Sep 2016 – Accepted for review: 13 Oct 2016 – Discussion started: 18 Oct 2016
Abstract. Improving international food security under a changing climate and increasing human population will be greatly aided by improving our ability to modify, understand and predict crop growth. What we predominantly have at our disposal are either process based models of crop physiology or statistical analyses of yield datasets, both of which suffer from various sources of error. In the current paper we present a generic process based crop model which we parametrise using a Bayesian model ﬁtting algorithm to three different sources of data – space based vegetation indices, eddy covariance productivity measurements and regional crop yields. We show that the model parametrised without data, based on prior knowledge of the parameters can largely capture the observed behaviour but the data constrained model greatly improves both the model ﬁt and reduces prediction uncertainty. We investigate the extent to which each dataset contributes to the model performance and show that while all data improves on the prior model ﬁt, the satellite based data and crop yield estimates are particularly important for reducing model error and uncertainty. Despite these improvements, we conclude that there are still signiﬁcant knowledge10 gaps, in terms of available data for model parametrisation, but our study can help indicate the necessary data collection steps for improvement in our predictions of crop yields and crop responses to environmental changes.
Caldararu, S., Purves, D. W., and Smith, M. J.: The impacts of data constraints on the predictive performance of a
general process-based crop model (PeakN-crop v1.0), Geosci. Model Dev. Discuss., doi:10.5194/gmd-2016-243, in review, 2016.