Has anyone attempted to estimate tree cover or general vegetative cover over impervious cover using the NLCD data sets? The provided layers (land classification, tree cover, impervious cover) could be combined to produce an estimate - and I currently have an algorithm that does this - but I'm wondering if anyone else has tried.
As an example of what I am talking about, one grid cell might be classified as medium density residential in the original data set (type = 23), with an impervious cover percentage of 70% and a percent tree cover of 40%. Obviously there is some overlap of canopy and impervious cover, since they sum to be greater than 100%. So, based on the fact this cell was classified as a medium density residential cell, we use a set of simple mathematical equations to estimate tree cover over impervious.
Link to NLCD data sets: http://www.mrlc.gov/nlcd2011.php