I want to know how many "tall" trees (greater than 30 m) fell down between 2005 and 2015. I have LIDAR imagery from 2005 and 2015 from an area where many tall trees are known to have fallen due to ice storms.
I created 2 tree height rasters, one for 2005 and one for 2015, by subtracting the ground height from the canopy height (I originally had 4 rasters). What I want to know is the total number of pixels that declined by at least 20 m in the period 2005-2015.
I've tried a variety of approaches with this and haven't quite figured it out. Does anyone have any good hints for me?
(using ArcGIS 10.2.1)