MODELING RELATIONSHIPS BETWEEN SOIL AND CLIMATE PARAMETERS USING THE BASIC GAPS PROGRAM

Recognizing relationships between soil and climate parameters is initially difficult because the data are seemingly disparate and difficult to graph. Basic GAPS v.5 is a Microsoft Excel program designed by Cornell University and NASA as “a tool for investigating the dynamic and complex systems of the global environment” (Cornell and NASA). The data sets come from the GLOBE Program, which was created in an effort to raise awareness of various types of climate, soil, and phenology data throughout the world. Basic GAPS is a way to enter data into tables, run models, and graph results. These graphs can be examined with the intent of finding patterns and making predictions. Data sets were obtained from various regions throughout the United States, and include variables such as precipitation, evaporation, transpiration, evapotranspiration, soil moisture, phenology, drainage, and runoff. A lab was designed to use the Basic GAPS program to illustrate these relationships in an introductory Physical Climatology course at Western Kentucky University.

The lab included data sets from Alabama and New Hampshire, chosen because of differences in soil textures. Data was directly imported into the modeling program, and examined using a variety of embedded graphs. The lab was developed and tested on twelve undergraduates and one graduate student at Western. A short presentation was given regarding Basic GAPS, then the students completed the lab exercises and turned them in, along with a questionnaire concerning the lab itself.

The students worked with seven graphs that included the variables mentioned above and answered three to four questions concerning the graphs. Students performed well, except in instances when they did not follow directions, or the data was not unambiguous. The consensus was that the program was easier to work with as the lab progressed. Suggestions included spelling out acronyms on the input pages, including a graph with incoming solar radiation information, and a “how-to” text box with information that would be useful to the student when working with the program.

The power point presentation, the data sets, Basic GAPS, and the Lab Exercises will be modified for use at the high school level. It will be useful to have more complete data sets to work with to get a broader sense of varying climates and soils.