I have 10 years of each year precipitation in shapefiles and would like to combine them into one to show years in ArcMap layer.

Do I need to use the append or union ?

closed as unclear what you're asking by whyzar, Dan C, BERA, Hornbydd, nmtoken May 2 '18 at 18:27

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I think this question is most easily answered by taking your shapefiles and doing two tests:

  • Append them together and examine the result
  • Union them together and examine the result

If either or both tests cause an error or do not meet your requirements then, after reviewing their documentation, you will be in a position to ask a more focussed question.

If one does almost, but not quite, what you what you want, then that too will place you in a better position to ask a more focussed question to try and uncover a more suitable solution to meet your requirements.

I would expect precipitation data to most likely be points which would seem to rule Union out as an option.

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