This document summarizes a study examining historical land cover classification at Cedarburg Bog in Wisconsin. The study aims to classify land cover in 1941 and 2000 from aerial photographs in order to identify changes over time in response to climate, land use, and human activities. The methods involve georeferencing and digitizing the 1941 aerial photos, classifying land cover into categories like forest, agriculture, water, and wetland, and comparing the results to published land cover maps from 1992 and 2001 to analyze major areas of land use change surrounding the bog over the past 60 years.

1. Historical classification of land cover at the Cedarburg Bog Jason Schroeder CES major – UWM 1 credit BIO SCI 699 with Dr. Erica Young

7. Georeferencing 1941 – raw unreferenced photo 2000 – georeferenced photo

10. 1941 Raw Image No spatial information 1941 GEOTIFF Coordinates imbedded

12. Detail of Mosaic process: merging overlapping images Overlap from two photos

13. Software generates a “cutline” Looks for pixels from each image that are similar to create seamless merge

14. Seamless merge – finished mosaic

15. Final mosaic – 15 photos merged together

17. ‘ Supervised’ classification Blue: water Green: forest Tan: agriculture By comparing this classification to the next slide, it is apparent that water is overrepresented - dark forest pixels are mistaken for water pixels.

20. Animated GIF from 1941 - 2000

21. 1941

22. 2000 Areas of major change: