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I am working on a dataset where I combined geographical information of cities in Europe and changes of landcover in these regions. I am working with the CORINE Dataset and I would like to know about the variation of changes in the whole area in different time periods. In the CORINE dataset you can find a lot of different changes (e.g. dense urban fabric -> parc areas (112-212) etc.). I'd like to combine all changes which are similar (see example above) in the observed area.

I managed to do a dissove where the output was only one field in the attribute table for one change (e.g 112-212) and I thought that's it. After some troubles I controlled the results and saw that the information about the size of the area is not the size of all combined areas what makes it unusable for me.

Some pictures might explain more than my words:

2 Datasets: Changes

Cities

I merged the two datasets to reduce information and to have the changes just at the area where the cities are and then used Dissolve to field "CHANGE" (worked) but I also need the cumulated information about all the areas where that change happened (area h and the number of areas which are now packed into one line in the attribute table (did not work)).

Dissolve

Do you have any solution for my problem?

  • It's not quite clear what the problem is for me.. cumulated information = sum statistics? – DirkB. Aug 21 '17 at 20:02
  • So, before dissolving you maybe run sum(expression, group_by, filter) in field calculator. then add that result to every change field, so after dissolving you should still have one field with that sum from cumulated changes – DirkB. Aug 21 '17 at 20:25

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