Tom's Blog

Saturday, January 22, 2011

Early air photos now available; useful for planning restorations

For years I have been using the early air photos taken by the Soil Conservation Service for planning restoration work at Pleasant Valley Conservancy. The first air photos for Dane County were taken in 1937, and show the property as it was at a time when farmers were still using annual fire. This air photo, and its interpretation, are shown on the PVC web site at the following link.

When I was starting out, these photos could only be acquired at considerable expense from the U.S. National Archives, although Robinson Map Library in Science Hall had a complete set for Dane County. Now, miracle of the Internet age, all these early air photos for the whole state of Wisconsin have been scanned by UW Digital Collections and are available for viewing and download through the State Cartographer's Office. Here is the link.

When you open this web site, you get a map of the whole state, and can move to and zoom in on any location. The base map here is a recent air photo, so you can see your land as it is today. You can key in the location you are interested in, or pan and zoom to it. Once you get there, you will see a series of dots, each with its code for the 1937 photo. Select the one you want and a preview screen appears on the left. You then have the option of downloading that photo at one of three resolutions: 150, 300, or 600 dpi. I would recommend using the low-resolution version first to be sure you have the correct image, and then download the 600 dpi version, even though it is a large file and downloading takes some time.

Just for fun, I downloaded the 300 dpi version for the area that includes the Schurch-Thomson site of the Prairie Enthusiasts. I then opened it in Photoshop and cropped to the area of interest, and then reduced the resolution so that it could be downloaded fast for this blog. Even with this low resolution, you can get some useful information. For instance, the site was mostly treeless, although there are areas around the barn (and the old house that has now been demolished) that have trees. This version is shown below.

I strongly recommend that anyone who is doing (or planning) a restoration download the relevant air photos for their property.

Why? See my earlier post on legacy effects!


Blogger Good Oak said...

This is great news as it will save me a lot of trips to the map library! Any news if later photo series will also become available online?

January 22, 2011 at 10:25 AM  

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