Location: National Soil Erosion ResearchTitle: A simple technique for obtaining future climate data inputs for natural resource models Author
|Trotochaud, Joseph - Purdue University|
|Engel, Bernard - Purdue University|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/24/2015
Publication Date: 6/27/2016
Citation: Trotochaud, J., Flanagan, D.C., Engel, B.A. 2016. A simple technique for obtaining future climate data inputs for natural resource models. Applied Engineering in Agriculture. 32(3):371-381.
Interpretive Summary: Changes in climate, such as increases in air temperatures, rainfall depths, and storm intensities, are occurring due to global warming resulting from increased greenhouse gases in the atmosphere. These changes can have serious implications for natural resources, in particular soil and water. Runoff from farm fields and associated soil erosion and pollutant losses may increase or decrease in the future, depending upon how local climates will be altered. Land management, cropping practices, and soil conservation tools may not be as effective in the future under warmer and wetter climate. In order to assess the impacts of these possible climate changes on runoff, soil erosion, and pollutant losses, we developed an easy-to-use tool to obtain future climate predictions for a location of interest, and format this information into climate input files to two widely-used natural resource models, the Water Erosion Prediction Project (WEPP) model, and the Soil and Water Assessment Tool (SWAT). This paper shows how the tool works, and the results of some example applications of it in northeastern Indiana with WEPP and SWAT. We found that projected changes in future climate can have a big effect on soil loss, but also conservation practices can still be very effective at controlling this. We also found that combinations of practices worked better than nutrient management only in reducing phosphorus losses from a watershed. This tool impacts scientists, university faculty and students, conservation agency personnel, extension agents, and others involved in assessment of land management practices on soil erosion and pollutant losses, as affected by projected climate changes. The availability of this tool will make climate change assessments with WEPP and SWAT much easier, producing more information more rapidly, and better recommendations for land management practices.
Technical Abstract: Those conducting impact studies using natural resource models need to be able to quickly and easily obtain downscaled future climate data from multiple models, scenarios, and timescales for multiple locations. This paper describes a method of quickly obtaining future climate data over a wide range of scenarios, models, and timescales from the Intergovernmental Panel on Climate Change AR4 and AR5 model families using the MarkSim DSSAT Weather Generator and a Microsoft Excel VBA Macro, the final result being a properly formatted .par file which can be used by CLIGEN (CLImate GENerator) within the Water Erosion Prediction Project (WEPP) model. By using software which already exists on most computers and not requiring climatological or modeling knowledge to operate, the method herein for creating WEPP climate input files is much faster and simpler than commonly used statistical methods currently described in the literature. Ultimately, the method was modified to create continuous daily data for use with the Soil and Water Assessment Tool (SWAT) as well. The final product is an automated spreadsheet with a simple user interface which imports, analyzes, and generates climate input files for the WEPP and SWAT models. This paper describes the methods, development, and testing of the tool for use with CLIGEN and WEPP model simulations.