Issue using Union tool to join to polygon layers

Discussion created by tucker.494 on Oct 29, 2013
Latest reply on Oct 29, 2013 by timw1984dev
Hi There,

I have a clipped polygon layer of National Land Cover Dataset (NLCD) 2006 and a National Wetlands Inventory (NWI) dataset layer for Ohio.  I need to overlay the two polygon layers together and have tried using Union under the Geoprocessing tab.  I did this several times.  Each time, in the resulting attribute table, the fields that should have information regarding the NLCD input layer are populated with -1s and 0s.  I used the Intersect tool to see what the result would be.  This actually worked in combining the information from both input layers.  Why is this not working with Union?

I've also tried converting the layers to Rasters and using the Mosaic to New Raster tool.  This accomplished nothing.  I was told I could try replacing values using Raster Calculator but I don't know how to do this.