Decision Models

Adaptation to climate variability or change requires decisions made in the face of uncertainty, and decision models can help resource managers explore options, risks, and trade-offs. Our approach to this challenge is to simulate the decision process so that managers can test the implications of multiple factors and decisions, and thus get a feel for how sensitive their choices are to uncertain conditions. We are developing a set of decision analysis models aimed at understanding, and simulating, the decision process for response to climate variation among resource managers like farmers, ranchers, conservationists and others. Decision analysis can:

  • Help analysts and decision-makers recognize the structure, trade-offs, and likely outcomes of a range of choices made under uncertainty;
  • Provide tools for testing how sensitive decisions are to climate variation, to improved information, or to down-side risks;
  • Suggest optimum, robust, or least-regret decisions.

This decision analysis page provides models under development that you can either download and try out yourself, or run on the web (different models have different user interface options).

Contacts: Bill Travis, Mary Huisenga

Farm Adaptation Model

Accessing the FarmAdap model:
You can run a simple version of the Farm model on Analytica’s “Cloud Player” by clicking here.

You can also download the model here and change inputs and run it (even without access to the full software), by downloading the free Analytica Player. (PC download only).

The “FarmAdapt” Model simulates costs, production, and net income for a 2,000 acre dryland wheat farm on the U.S. Great Plains, with the goal of modeling the impacts of climate variation, especially extreme events and rapid climate change, and the timing of farmer adaptation. Climate change is input via off-sets to the mean of the yield distribution from which the farm draws each year in a 30 year simulation. The model is calibrated on actual yield data for central North Dakota wheat production, plus a set of scenarios of gradual or rapid change as well as extreme events. Yield data could be input from, for example, a historical time series of a particular farm, county or climate division, or simulated future yields simulated by a combination of climate scenario and crop yield modeling.

We have loaded the cost, yield, and price data, and if you simply run the model (by clicking either of the “Calc” buttons) you will get results for all the scenarios and be able to scroll through “slices” to see all the output:

Once you have down-loaded the free Analytica player and downloaded the model from this site, you can simply run it and explore the many results, or you can change some of the parameters and then run it.

spreadsheet modelWe have given the farmer the choice of switching methods from continuous cropping (common in the region) to an alternate fallow system (common further west in drier areas, and generally producing a slightly higher yield) if the continuous cropping yields decline too much. You can set the income threshold for this switch in the user interface. We start at $-50,000 for reasons described in the accompanying white paper. Results then give you the future incomes for the non-adaptive (stays with continuous cropping) and the adaptive (switches) farmer. You can view the details of the model by clicking on the “Model” node in the center.
An Excel spreadsheet version of the FarmAdap(.xlsx) model can also be downloaded here.

This spreadsheet model was developed with the @Risk from Palisades Software where you can download a trial version of the @Risk add-in for Excel. You can also see the basics of the model, and results from its last run, in the Excel spreadsheet without the @Risk add-in. This version of FarmAdap is not a dynamic simulation as with the Analytica version described above, but it has useful, transparent features such as a running Net Present Value calculator.

For more information, contact Bill Travis or Mary Huisenga, Dept. of Geography, University of Colorado at Boulder