1. Deforestation: An Exponential Problem By Carla McAuliffe

2. Investigation Question(s) How quickly or slowly are forested regions being cleared in the Amazon basin? At what rate is deforestation occurring over time?

3. Activity Description S tudents will download a set of four images, showing deforestation of an area of Brazil. The images were taken across a twenty-six year period. Students will use ImageJ to stack, animate, and explore the set of images. They will quantify the deforestation by measuring cleared areas in pixels via thresholding. Then they will export the area measurements as a text file, add a column for the year of each image, and produce a line graph in Excel.

4. Data & Analysis Tools ImageJ and Excel http://svs.gsfc.nasa.gov/vis/a0000 00/a002100/a002116/index.html Landsat images of a section of Rondonia, Brazil for the years 1975, 1986, 1992, and 2001. Images come from Scientific Visualization Studio.

5. Curricular Support While studying changes in ecosystems over time: –Students will gain awareness of the impacts that humans can have on the environment. –Students will recognize that some environmental problems occur at exponential rates.