FACCE MACSUR Reports (Modelling European Agriculture with Climate Change for Food Security)
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Integrated assessment of policy and climate change impacts: A case study on protein crop production in Austria
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A prototype stochastic dynamic equilibrium model of the global food system
No full textThe risks of food consumption are primarily linked to those of food production due to stochastic weather. Other sources of risk are associated with break-down of food trade or transport for weather or political reasons. Hopefully, future cures against increased risk due to climate change may be found with new agricultural technologies, systems of storage from favorable to unfavorable periods, more flexible trade-arrangements between favorable and unfavorable places. However, in the short run one has to rely on the available technology, storage facilities and trade agreements. With a realistic model of the stochastic global food system, it should be possible to measure risks of certain extreme unfavorable events.A realistic case will have countries with different climate in different growing seasons. Markets will be open for trade at a number of points per year, in which decisions of production, storage, trade and consumption can be coordinated as a static equilibrium. Determinants of this equilibrium are the weather up to this date reflected in the state of crops, the available harvested stocks and the decision-maker's preferences. With a global stochastic process of weather, a stochastic sequence of equilibria follows
Fuzzy-logic based multi-site crop model evaluation
Get PDFThe most common way to evaluate simulation models is to quantify the agreement between observations and simulations via statistical metrics such as the root mean squared error and the linear regression coefficient of determination. It is agreed that the aggregation of metrics of different nature intro integrated indicators offers a valuable way to assess models. Expanded notions of model evaluation that have recently emerged, based on the trade-off between properties of the model and agreement between predictions and actual data under contrasting conditions, integrate sensitivity analysis measures and information criteria for model selection, as well as concepts of model robustness, and point to expert judgments to explore the importance of different metrics. As a FACCE MACSUR CropM-LiveM action, a composite indicator (MQIm: Model Quality Indicator for multi-site assessment) was elaborated, by a group of specialists, on metrics commonly used to evaluate crop models (with extension to grassland models) while also integrating aspects of model complexity and stability of performances. The indicator, based on fuzzy bounds applied to a set of weighed metrics, was first revised by a broader group of modellers and then assessed via questionnaire survey of scientists and end-users. We document a crop model evaluation in Europe and assess to what extent the MQIm reflects the main components of model quality and supports inferences about model performances
Observed and simulated growth, development and yield of field-grown tomato in the Elbe lowland, the Czech Republic
No full textThis study deals with observed and simulated growth, development and yield of the fresh-market Thomas F1 tomato bush cultivar (Solanum lycopersicum L.) grown under open field conditions at farm scale in the Elbe lowland. The CROPGRO-Tomato model used in this study is part of the DSSAT V4.5 software. The model has been calibrated with growth analyses data from field experiments, agronomic evidence (GC UPRAVY software) and the most currently available data from the literature sources of cardinal temperatures for tomato phenology, fruit growth and photosynthesis (Tb - base temperature; Topt1 - the lowest temperature at which maximum rate is attained; Topt2 - the upper temperature at which maximum rate is sustained; Tmax - maximum temperature). The sampling plants were collected a once 14 days for analysis of basic physiological parameters: LAI (Leaf area index), LAR (Leaf Area Ratio), C (Crop Growth Rate), RGRw (Relative Growth Rate) and NAR (Net Assimilation Rate). Phenology observation was done weakly. Meteorological, soil and agro-technical parameters across the fields were monitored. The treatments were well-irrigated and well-fertilised, and therefore, no water or N stress was present.Parameters affecting leaf growth, dry biomass productions, and dry biomass of leaves, stem and generative organs from planting to harvest were calibrated against the observed data. Phenological development and growth processes such as leaf expansion and fruit growth depend on cardinal temperatures. Leaf area expansion depends on the new leaf mas produced and specific leaf area, which is influenced by light, temperature, root N uptake, and plant water status. Starting date for the simulation corresponds with transplanting date of the crop in the field, which was set at day 141. The simulation period ended at day 273, a reasonable estimate for the date when plants are stopped in practice. Initial input dry biomass at Mochov farm (Suchdol) was set to 2.25 (2.88), 1.71 (2.5) and 0.01 (0.78) grams for leaves, stem and generative organs, respectively
Quantified Evidence of Error Propagation
No full textError propagation within models is an issue that requires a structured approach involving the testing of individual equations and evaluation of the consequences of error creation from imperfect equation and model structure on estimates of interest made by a model. This report briefly covers some of the key issues in error propagation and sets out several concepts, across a range of complexity, that may be used to organise an investigation into error propagation
Methods for risk analysis and spatial upscaling of process-based models: Experiences from projects Carbo-Extreme and GREENHOUSE
No full textIn the recently finished EU-funded project Carbo-Extreme, we developed a simple probabilistic method for quantifying vulnerabilities and risks to ecosystems (http://iopscience.iop.org/1748-9326/8/1/015032). The method defines risk as expected loss due to environmental hazards, and shows how such risk can be calculated as the product of ecosystem vulnerability and hazard probability. The method was used with six different vegetation models to estimate current and future drought risks for crops, grasslands and forests across Europe (http://www.biogeosciences.net/11/6357/2014/bg-11-6357-2014.html).In the still ongoing UK-funded project GREENHOUSE, the focus is on spatial upscaling of local measurements and model predictions of greenhouse gas emissions to wider regions. As part of this work, we are comparing different model upscaling methods – ranging from naive input aggregation to geostatistics – and quantify the uncertainties associated with the upscaling. This work builds on an earlier inventory of model upscaling methods that was produced in a collaboration of CEH-Edinburgh and the University of Bonn (https://www.stat.aau.at/Tagungen/statgis/2009/StatGIS2009_Van%20Oijen_1.pdf). Here we show a comparison of the methods using model predictions for the border region of England and Scotland
Modelling regional agricultural land use and climate change adaptation strategies in 4 case study regions Northern Germany
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Analysis of climate change adaptation with bio-economic farm models: lessons from MACSUR regional pilot studies
Get PDFIntegrated land use models (ILM) featuring agronomic and economic drivers of land use are frequently applied to serve the high information demand of stakeholders. This presentation results from collaboration among bio-economic farm modelers across the MACSUR regional pilot studies (www.macsur.eu) and shall compare and finally reveal good practice examples on the representation of climate change adaptation in bio-economic farm models. First results show a considerable diversity of approaches employed in the MACSUR regional pilot studies. All are programming models that optimize more or less elaborated forms of utility. All consider or plan to consider crop yield impacts from bio-physical crop models based on daily-resolution climate data. While some models include pest and diseases or livestock impacts, none take climate change impacts on market prices or interactions among farms into account so far. Clearly, adaptation options determine the solution space and are mainly expert-based in the regional case studies. Overall, the models are normative and analyze economically rational and optimal land use and management at the farm level, capable of showing the likely direction of differences in future management as a response to exogenous parameter changes (prices, yields, disease pressure, changed policy conditions, etc.). Such detailed models and their results may be applied in stakeholder interaction. Integrating the different direct and indirect effects of climate change, including the policy dimension, is the main contribution of farm level modelling of agricultural systems in the domain of climate change adaptation research