Land Use layer by combining, removing attributes and assigning new attributes

Question

I'm working in ModelBuilder and I have limited (let's face it, no) Python knowledge, so I'd like to stay here if possible!

I have numerous shapefiles that I want to combine into a single land use layer, but I want the shapefiles to be classified into one of three categories. I'm not interested in keeping the original attributes; I just want the areas which can be combined and don't have to be separate.

My original files look like this:

• A.shp - 90 rows, 10 fields
• B.shp - 2500 rows, 15 fields
• C.shp - 150 rows, 10 fields
• D.shp - 500 rows, 3 fields
• E.shp - 750 rows, 3 fields
• F.shp - 150 rows, 15 fields
• G.shp - 200 rows, 15 fields

and I want the final output to look like:

• FINAL.shp - 3 rows (land use type A, B and C), 1 field (land use type)

The land use type is not specified anywhere in the original tables; I would have to specify this somewhere in the model.

If I were doing this manually in ArcMap, I would do something like:

1. Go through the shapefiles one by one, merging the rows.
2. Open the attribute tables one by one and delete the columns.
3. Create a blank shapefile and copy the land use A areas then merge them, then do the same for B and C.

Is there an easier way?

Answer 1

If I understand correctly, each of the input shapefiles consists of only one land use type. If that's the case, here's what I would suggest:

1. Use the Merge tool three times to merge all of the A, B and C input shapefiles into three new shapefiles, each containing all polygons of a single land use type.
2. On each of the merged shapefiles, run the Dissolve tool with nothing specified as the "dissolve field". This will eliminate all of the original attributes from the output.
3. For each of the dissolved shapefiles, use the Add Field tool to add a "land use type" field. Make sure the field type (and length, if applicable) are the same for each. Use the Calculate Field tool to set the values for this field in each of the three shapefiles.
4. Use the Merge tool once more, this time merging the three dissolved shapefiles with land use type fields into your final output shapefile.