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Webber, H., Gaiser, T., Oomen, R., Teixeira, E., Zhao, G., Wallach, D., et al. (2016). Uncertainty in future irrigation water demand and risk of crop failure for maize in Europe. Environ. Res. Lett., .
Abstract: While crop models are widely used to assess the change in crop productivity with climate change, their skill in assessing irrigation water demand or the risk of crop failure in large area impact assessments is relatively unknown. The objective of this study is to investigate which aspects of modeling crop water use (reference crop evapotranspiration (ET0), soil water extraction, soil evaporation, soil water balance and root growth) contributes most to the variability in estimates of maize crop water use and the risk of crop failure, and demonstrate the resulting uncertainty in a climate change impact study for Europe. The SIMPLACE crop modeling framework was used to couple the LINTUL5 crop model in factorial combinations of 2-3 different approaches for simulating the 5 aspects of crop water use, resulting in 51 modeling approaches. Using experiments in France and New Zeland, analysis of total sensitivity revealed that ET0 explained the most variability in both irrigated maize water use and rainfed grain yield levels, with soil evaporation also imporatant in the French experiment. In the European impact study, net irrigation requirement differed by 36% between the Penman and Hargreaves ET0 methods in the baseline period. Average EU grain yields were similar between models, but differences approached 1-2 tonnes in parts of France and Southern Europe. EU wide esimates of crop failure in the historical period ranged between 5.4 years for Priestley-Taylor to every 7.9 years for the Penman ET0 methods. While the uncertainty in absolute values between models was significant, estimates of relative changes were similar between models, confirming the utility of crop models in assessing climate change impacts. If ET0 estimates in crop models can be improved, through the use of appropriate methods, uncertainty in irrigation water demand as well as in yield estimates under drought can be reduced.
Keywords: crop model; impact assessment; crop water use; evapotranspiration; irrigation; drought; uncertainty
Area: CropM
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Frank, S., Witzke, P., Zimmermann, A., Havlik, P., & Ciaian, P. (2014). Climate Change Impacts on European Agriculture: A Multi Model Perspective.. |
Zimmermann, A., Witzke, H. - P., & Heckelei, T. (2013). Filling gaps: AgMIP scenario results from CAPRI (Vol. 2).
Abstract: Climate change impacts on food production, socioeconomic changes (population and income growth in large parts of the world) and biofuel policies affecting demand quantities have risen scientific, political and public interest in long-term forecasts on food security. Whereas first quantitative analyses from global economic models are starting to appear (e.g. (von Lampe et al., under review)), similar studies on smaller regional scales are not yet available. However, acknowledging that climate change affects crop yields differently across scales and regions (e.g. (Reidsma et al., 2007)) and considering the specific political setting given through the Common Agricultural Policy (CAP) in Europe, the MACSUR project focuses on the impact of climate change and socioeconomic changes on European agriculture and its contribution to global food security. We present a Europe-wide analysis of the effect of selected climate and socioeconomic scenarios on food security in terms of food prices using the Common Agricultural Policy Regionalised Impact modelling system (CAPRI). No Label
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Köchy, M., & Zimmermann, A. (2013). Workshop on Regional Pilot Studies, 5-7 June 2013, Braunschweig (Vol. 2).
Abstract: The workshop was called to define an overarching question to be answered by all Regional Pilot Studies and to select from the existing studies those that fit best to the aims of MACSUR. The question that evolved from the discussions is “What would be the different contributions of different European adaptation strategies to ensure global food security until 2050 at different scales (farm to EU) while keeping the GHG targets?” Workshop participants agreed to use the newest climate simulations related to Representative Concentration Pathways that were also used by the AgMIP and ISI-MIP projects. There was also agreement to use a subset of the AgMIP scenarios (S2-S6) for impact assessments, with AgMIP scenario S1 as the reference scenario, for details see Table 3 below. The selection of Regional Pilot Studies was discussed separately for European Grand Regions, but there was no concluding decision taken. The Project Steering Committee will finally decide on showcase studies at a meeting in the first week of July based on characterisations sent in by interested members. Questionnaires for characterising the Regional Pilot Studies will be sent by the Hub to the regional contact persons mentioned in Table 2 to fill in. The characterization list can be extended. The questionnaires should be filled in by the end of June. Stakeholder meetings are planned for October 2013 in each region where preliminary/sample outputs of the regional pilot studies should be presented. Results will be presented at the mid-term meeting in April 2014. The last year of MACSUR is then available to improve the studies.The geographic extent of the Regional Pilot Studies is approximately county level – representing the area of the studies they are based on. The Regional Pilot Studies will be linked within the grand regions (northern, central, southern Europe) by consistent regional and continental Representative Agricultural Pathways (RAP). These regional RAPs will feed into the RAP process underway at AgMIP. Through the common RAPs the Regional Pilot Studies will reflect the common challenges of the greater region and by having several Regional Pilot Studies the diversity of the environment, farming systems, and political systems is represented. The workshop was a first step into further planning and performing the Regional Pilot Studies that will fine-tune the results of the workshop. No Label
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Zimmermann, A. (2015). Crop yield trends and variability in the EU (Vol. 5).
Abstract: Agreeing that increased future global food demand will have to be met by production intensification rather than land use expansion (e.g. Hertel, 2011), scientists have moved to empirically analyse the causes for differences between potentially attainable yields and actually realized yields – the yield gap (e.g. van Ittersum et al., 2013, Neumann et al., 2010). In the long run, we aim at disentangling the effects of biophysical, economic and political impacts and farmers’ response to them on crop yields by analysing yield gaps at regional scale in the European Union. Apart from generally improving our understanding of yield gaps and their drivers in the EU, our analysis will contribute to the integration of economic and biophysical models at a later stage of our research. As a first step towards an advanced yield gap analysis, the current paper will give an overview of yield developments in the EU27. The overview will be based on regional yield trend and yield variability estimates derived from socioeconomic panel data from the Farm Accountancy Data Network (FADN). The analysis will continue and extend the work of Ewert et al. (2005) and Reidsma et al. (2009) in terms of drawing on single farm instead of country level/farm type data, including the new EU member states and most recent years (until 2011). The EU-wide analysis of yield trends and variability will serve as a basis for the later analysis of yield gaps. No Label
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