Im doing a project where I'm creating a map that shows how land use changed from 1990-2000 for the city of Minneapolis. I have three files, one of the cities boundaries, one with the land use of the 2000's and the other has the land use of 1987, 1990, 1997, and 2000. I merged and intersected the land use .shp with the city land cover .shp. However I'm having trouble showing how land use changed. I'm having difficulty because the land use history .shps have over 80,000 files. Because of the large number of files its not easy for the naked eye to see the polygons. Any ideas on how I can make the changes more easily perceivable.

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    Can you clarify: Do you really have 80,000 files open at once? You initially say that you have two land use files (plus city boundaries) and then end by saying that the SHPs have 80,000 files. Do you really mean files or records? Use the dit button to alter your question. Mar 4 '16 at 17:29
  • I meant that one of my files (land use for 1990's) had over 80,000 files within it. Thanks! Mar 5 '16 at 21:01
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    I think you mean one of you files has 80,000 features or records. Mar 5 '16 at 22:22

A few ideas, though it would help if you included a screenshot.

  • don't show polygon boundaries
  • convert to raster (would be faster, have no boundaries, and possibly easier to show diffs)
  • use a series of maps focused on different parts of the city
  • merge classes into super categories (e.g. just residential, commercial, industrial, rural, natural)
  • simplify your feature geometries
  • develop a binary classification (e.g. changed or not changed; rural or urban; developed or undeveloped) and only show that
  • pick one class and make several "small multiple" maps showing changes to just that class (Google Tufte)
  • If this has been helpful then you should accept the answer by clicking on the tick button. This indicates that you've had a satisfactory answer and helps other people use the site. Mar 5 '16 at 22:25

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