Activities areas in output rasters smaller in area than reported in html
I was doing some calculations for the RIOS outputs for several watersheds. In order to do so, I converted the total portfolio raster output to shapefile. When doing the conversion, I was very careful not to simplify the polygons, so the resulting shapefile would have the same areas as the original raster. After that, I calculated the areas for the various activties, and then summed them up per watershed, and I noticed that the resulting areas are smaller than those in the html report. I'm enclosing a screenshot featuring a comparison between my calculations and the html report for one watershed as an example, but this happened to all the watersheds I ran the model for.
Does anyone have had this problem before?
Thanks in advance