I am trying to get the area coverage of a layer in my map, and the two methods I've used to do so are producing different results.
I used dissolve to create one feature in the layer and get the SHAPE_Area off the attribute table, and then I unioned the layer and summed the areas from that result. The dissolve is giving me 654901660.917106 m^2, and the summed union is giving me 1316663489.162411 m^2. Everything is using the same projected coordinate system. Anybody know what is happening?? This is driving me crazy...
you might want to run the Multipart to singlepart tool as well and use the AddGeometryAttributes tool to confirm shape area values. Check the latter result against a polygon that had no overlaps or adjoining polygons to confirm the process
The multipart to singlepart tool didn't seem to help, but I was able to identify some overlap in the union, and feel more confident that the dissolve tool is giving the correct area now. Thank you!