Aerial photography of the coastline in the prototype counties is available dating back to the late 1930s. The photography is useful as a second measure of bluff line recession.

This task will consist of gathering historic photos of the shoreline in the five prototype counties, registering the photos to the digital orthophoto base maps, delineating a bluff line on each photo, and calculating the recession rate between each historic photograph.

Historic top of bluff was delineated for several historic periods in 2000. This work will be completed for all five prototype counties in 2001.

For each prototype county, historic photos will be used to develop independent recession rates. The recession rates will be used as an independent check on the recession rate data base and model predictions. Depending on the success of this task, it may be expanded to the remaining counties on Lake Michigan.

The figure below provides an example of historic photo analysis with 1978 (green) and 1999 (red)(very faint on image) top of bluff positions indicated.

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