Tom's Blog

Monday, July 16, 2012

Drought history of our area

We are now "officially" in a serious drought and who knows how long it will last. I find it useful to look at an overview of the drought history of our area, since it helps to put this current situation in perspective.

There are a number of different ways of expressing drought, and one index used by climatologists and agriculturalists is the Palmer Drought Severity Index. The Wisconsin Climatology Office has a nice graph that gives Palmer data from 1895 until today, and this graph is interesting to look at.

The period that we have been restoring Pleasant Valley Conservancy (1995 to the present) has been primarily a "wet" period. Only 2003 and 2005 have been on the negative side, and these have been not very severe. The major periods of the most serious drought were the early 1930s (the "dust bowl" period) and 1955-1967. There was a sharp peak in  1976-1977 and a less serious one in the late 1980s (the famous Yellowstone fires were in 1988).

Is the current drought a brief "blip" or does it represent the first stage in a new major drought period? We'll have to wait and see.

Obviously, those years when we were planting new prairies and savannas (1998-2005) were very favorable (that is, wet) years. Fortunately, most of our planted prairies and savannas are now well established and will hopefully be able to struggle through the current drought. Only the East Basin, planted in 2009,  is at a critical stage (its third growing season) and is hence potentially at risk.We were obviously just lucky that we did our major restoration work during a wet period.

Those thinking of planting new prairies now might want to think about the Palmer Drought Index data.


Post a Comment

Subscribe to Post Comments [Atom]

<< Home