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I am using an intersect/dissolve feature workaround in ArcGIS Desktop 10.5.

I have a layer of districts of a city and another layer of parks in the whole city /layer of noise amount around big streets. I want to compute the coverage of that two features in comparison to the whole district area.

For doing so, I first intersect my layer of parks/noise-layers with the districts layer to get the parks/... in that certain district. After that, I dissolve the outcome for the districts to only have the districts as my main features, as these are the main interest.

My problem arises, when there are no parks or noise layers in a certain district because then the intersect logically cannot intersect anything, so no feature for a certain district is created. When I later want to show the quantities of the coverage to compare the values I have, that certain districts shows up as empty field.

For the comparison I join the dissolved parks/noise-layer on the first district layer over the single districts. As described above, the intersect and with that also the dissolved parks/noise-layer, has for certain districts no data. So in the end these data show up in the districts layer as null values, because they don't exist.

I do not have any idea how to preserve a certain district even if he has no parks/noise-layers inside. I should have value zero but I cant find any option for keeping this, and because that's the scope of the intersect function I would not make sense.

My Main Focus is every single district and if it in the end does not show up I lose information.

Are there other functions that match my need?

Or did I forget something in my workaround?

image for clarification the image shows the districts where no noise-layer is intersecting with the district layer so in the end it does not have any data to be shown attribute-table of joined table at the endthe table shows the joined district layer with the coverage layer from the noise-layer

  • Welcome to GIS SE. Your question is very detailed by my brain finds it difficult to process. Could you post a screenshot to make your point clear ? For what I understand, you could intersect the district and the noise polygon layer. Then you could just do a spatial join to get the district_intersect_noise layer info into the park layer. But i may not have understood well what your problem is... – gisnside Dec 3 '17 at 21:01
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    It seems that Intersect is the wrong overlay function for your use case. Instead you want Union. I'm used to using databases, so I wouldn't ever Dissolve without a pressing need for the geometry, not when I have GROUP BY (or SummaryStatistics) available for calculation. – Vince Dec 4 '17 at 1:09
  • Transfer results of first and second interest to district table and replace null by 0. – FelixIP Dec 4 '17 at 3:16
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    Agree with Vince that you need to use union instead of intersect. This should solve your problem. – jbalk Dec 4 '17 at 6:28
  • Union just throws more or less everything together and in the end i cant dissolve that into the single districts because the noise-layer is the same layer as the district layer. So i cant calculate the area of that noise layer. FelixIPs suggestion is also what i thought, but somehow when i start an edit session it doesnt let me change any value of that table. Maybe because it is a joined table (districts joined with noise layer via district name)? The noise layer has for some districts no geometries so in the end when i join with the districts layer they appear as NULL... – xibalba Dec 4 '17 at 11:38

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