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Author Kuhnert, M.; Yeluripati, J.; Smith, P.; Hoffmann, H.; van Oijen, M.; Constantin, J.; Coucheney, E.; Dechow, R.; Eckersten, H.; Gaiser, T.; Grosz, B.; Haas, E.; Kersebaum, K.-C.; Kiese, R.; Klatt, S.; Lewan, E.; Nendel, C.; Raynal, H.; Sosa, C.; Specka, X.; Teixeira, E.; Wang, E.; Weihermüller, L.; Zhao, G.; Zhao, Z.; Ogle, S.; Ewert, F.
Title Impact analysis of climate data aggregation at different spatial scales on simulated net primary productivity for croplands Type Journal Article
Year 2016 Publication European Journal of Agronomy Abbreviated Journal European Journal of Agronomy
Volume 88 Issue Pages 41-52
Keywords Net primary production; NPP; Scaling; Extreme events; Crop modelling; Climate Data; aggregation
Abstract For spatial crop and agro-systems modelling, there is often a discrepancy between the scale of measured driving data and the target resolution. Spatial data aggregation is often necessary, which can introduce additional uncertainty into the simulation results. Previous studies have shown that climate data aggregation has little effect on simulation of phenological stages, but effects on net primary production (NPP) might still be expected through changing the length of the growing season and the period of grain filling. This study investigates the impact of spatial climate data aggregation on NPP simulation results, applying eleven different models for the same study region (∼34,000 km2), situated in Western Germany. To isolate effects of climate, soil data and management were assumed to be constant over the entire study area and over the entire study period of 29 years. Two crops, winter wheat and silage maize, were tested as monocultures. Compared to the impact of climate data aggregation on yield, the effect on NPP is in a similar range, but is slightly lower, with only small impacts on averages over the entire simulation period and study region. Maximum differences between the five scales in the range of 1–100 km grid cells show changes of 0.4–7.8% and 0.0–4.8% for wheat and maize, respectively, whereas the simulated potential NPP averages of the models show a wide range (1.9–4.2 g C m−2 d−1 and 2.7–6.1 g C m−2 d−1for wheat and maize, respectively). The impact of the spatial aggregation was also tested for shorter time periods, to see if impacts over shorter periods attenuate over longer periods. The results show larger impacts for single years (up to 9.4% for wheat and up to 13.6% for maize). An analysis of extreme weather conditions shows an aggregation effect in vulnerability up to 12.8% and 15.5% between the different resolutions for wheat and maize, respectively. Simulations of NPP averages over larger areas (e.g. regional scale) and longer time periods (several years) are relatively insensitive to climate data.
Address 2016-09-13
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Newsletter July Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition (up)
ISSN 1161-0301 ISBN Medium Article
Area Expedition Conference
Notes CropM, ft_macsur Approved no
Call Number MA @ admin @ Serial 4775
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Author Mansouri, M.; Dumont, B.; Destain, M.-F.
Title Predicting Grain Protein Content of Winter Wheat Type Conference Article
Year 2014 Publication Abbreviated Journal
Volume Issue Pages
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Area Expedition Conference 22nd European Symposium on Artificial Networks, Computational Intelligence and Machine Learning. Bruges, Belgium, 2014-04-23 to 2014-04-25
Notes Approved no
Call Number MA @ admin @ Serial 2631
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Author Wallach, D.; Nissanka, S.P.; Karunaratne, A.S.; Weerakoon, W.M.W.; Thorburn, P.J.; Boote, K.J.; Jones, J.W.
Title Accounting for both parameter and model structure uncertainty in crop model predictions of phenology: A case study on rice Type Journal Article
Year 2016 Publication European Journal of Agronomy Abbreviated Journal European Journal of Agronomy
Volume Issue Pages
Keywords Uncertainty; Phenology; Parameter uncertainty; Multi-model ensemble; Generalized least squares; Rice; Crop model; APSIM; DSSAT
Abstract We consider predictions of the impact of climate warming on rice development times in Sri Lanka. The major emphasis is on the uncertainty of the predictions, and in particular on the estimation of mean squared error of prediction. Three contributions to mean squared error are considered. The first is parameter uncertainty that results from model calibration. To take proper account of the complex data structure, generalized least squares is used to estimate the parameters and the variance-covariance matrix of the parameter estimators. The second contribution is model structure uncertainty, which we estimate using two different models. An ANOVA analysis is used to separate the contributions of parameter and model uncertainty to mean squared error. The third contribution is model error, which is estimated using hindcasts. Mean squared error of prediction of time from emergence to maturity, for baseline +2 °C, is estimated as 108 days2, with model error contributing 86 days2, followed by model structure uncertainty which contributes 15 days2 and parameter uncertainty which contributes 7 days2. We also show how prediction uncertainty is reduced if prediction concerns development time averaged over years, or the difference in development time between baseline and warmer temperatures.
Address 2016-09-13
Corporate Author Thesis
Publisher Place of Publication Editor
Language Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition (up)
ISSN 1161-0301 ISBN Medium Article
Area CropM Expedition Conference
Notes CropM; wos; ftnotmacsur; wsnotyet; Approved no
Call Number MA @ admin @ Serial 4777
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Author Mansouri, M.; Dumont, B.; Destain, M.-F.
Title Bayesian methods for predicting and modelling winter wheat biomass Type Conference Article
Year 2014 Publication Abbreviated Journal
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Area Expedition Conference MACSUR CropM International Symposium and Workshop: Modelling climate change impacts on crop production for food security, Oslo, Norway, 2014-02-10 to 2014-02-12
Notes Approved no
Call Number MA @ admin @ Serial 2629
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Author Mansouri, M.; Dumont, B.; Destain, M.-F.
Title Bayesian methods for predicting LAI and soil moisture Type Conference Article
Year 2012 Publication Abbreviated Journal
Volume Issue Pages
Keywords CropM
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Area Expedition Conference 11th International Conference on Precision Agriculture. Indianapolis (USA), 2012-07-15 to 2012-07-18
Notes Approved no
Call Number MA @ admin @ Serial 2627
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