How to merge overlapped shapefiles without one layer's overlapping area?

Question

I created a forest type map from 50 scene satellite images as shapefile under the following conditions.

• Some shapefiles are overlapped, because scene overlaps each other.
• There is an order of shapefiles in the table of contents.
• Merged file has to be follow the order. It means below shape file is not necessary in the overlapping area.

It is possible merging files, if I clip one by one, even though it takes a time.

Please let me know, if someone knows a more efficient way to resolve this issue.

Answer 1

Union will give you a mess with the attributes buried deep in several instances of the field names and probably numerous sliver polygons that will take days to rectify.

As you have a definite order of precedence for your inputs Erase first to clear the way and then append. Use the top order to erase next order and so on until the bottom shape file then it is safe to append.

If you only have a few to do, or another one pops up later, consider the Update tool which is basically an erase and append cycle in one tool.

Answer 2

This is as complete a break down as one could want: https://blogs.esri.com/esri/supportcenter/2014/12/02/combining-spatial-data-in-arcmap/

Answer 3

If I understand well what you are asking, you could use "union" after merging all you shapefiles (with the merge shapefile as single input), then dissolve to get rid of unnecessary boundaries.

Answer 4

I would recommend union as well. Dissolve or trim could be used (dissolve after trim before) in order to get rid of excess polygon shape.