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I have 2 maps with district borders of a region. Each district has its own unique ID number.

From one map to another some districts gave a small part of their territory to the neighboring districts and I want to make a map containing only these small areas that changed districts.

The borders of the 2 maps are badly designed and I can't overlay the maps and pick the areas where the borders change because in the end I would have many areas that come form the bad design and not only the ones that actually change district.

But I know exactly which district lost a part and which district received it, using their ID number.

i.e. An area moved from district with ID:1 to district with ID:2 but I know nothing else about this area.

Is there a way to make a map from these area using only their unique ID?

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I may be expanding too much on this, but I'm assuming that Area ID 1 and Area ID 2 are your two separate maps. If so, do the shapefiles have any other attributes? Specifically if you have an Object_ID field for your ID 2 shapefile, then you could try sorting this attribute and selecting the most recent Object_ID's from the list to see if they correspond to the areas lost by the other District.

Otherwise you may have to go back to the source document. The districts and boundaries that I deal with are all governmental and have to be filed somewhere. For my job, the pertinent documents get filed at the County Clerk's Office. You could pull the source documents for this flip-flop of the two districts to get surveyor's field notes or coordinate data or whatever additional documentation that you may need.

Eventually if you are to be working with this data in the future you may want to create a Creation Date attribute and Editor field in your shapefile and then assign your shapefile to autofill these attributes in ArcCatalog so that you can track changes.

  • Thanks for your answer, but the shapefiles only have the ID number of each district nothing else. Even if a source document exists (which I doubt) I don't have access to it. I'm going to check if a source document exists just to make sure but most likely I'll have to find another way to do it. – pef frank Feb 3 '16 at 8:17

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