Calculating diversity on a raster via a moving window

Discussion created by tayler.hamilton on Mar 1, 2011
Latest reply on Jun 18, 2013 by SWalbridge-esristaff

I have a raster data file of 18 different land cover classifications. I would like to calculate the land cover diversity using the Simpson diversity index:

Diversity = 1 - ??? sqr(P_i)

Where, "P" is the proportion of each land cover type within the neighbourhood and "i" is the different types of land cover.

The land cover data is displayed as unique values.

I would like to use a moving window of a specific neighbourhood size to calculate the diversity index.

So far, I have used focal statistics to calculate the variety (which I understand can represent the different number of land cover types within the area, or richness).

I was wondering, how do I determine the proportion (evenness) of each different land cover type within the same neighbourhoods? I was hoping I could calculate this and then use both results (variety and evenness) in the raster calculator to output the diversity model.

If anyone knows what I am talking about and can point me in the right direction, it would be VERY much appreciated!!!

Thank you,