Calculating field while dissolving in ArcMap

Question

I have two polygon Layers, A and B correspondingly. The polygons of B are lying on top of layer A and also overlapping the polygons of A (I made an example of the attribute table for better understandings).

I want to keep track of how much percentage of polygon A has "value_1" in different categories in it ("value_1" is originally from polygon B).

Example. Let's say my attribute table looks like this:

A_ID  B_ID  area_a  area_b  %area  value_1 
1      1     100     30       30     2        
1      2     100     45       45     5
1      3     100     25       25     16

2      4     50      10       20     12
2      5     50      30       60     5
2      6     50      10       20     5

The Output should look like this:

ID_A  area_a  value_1 <10  value_1 <20
1       100     75%            25%
2       50      80%            20%  

I guess I have to dissolve "A_ID" but I don't know how to calculate the field 'value1_ < 10' and 'value1_ < 20' while dissolving. Any suggestions?

Answer 1

Offhand, I think the best bet would be to classify your data before doing the dissolve.

As an example, creating a new field called "Classified", then select all values that meet your requirement. IE: Select where "Value1 < 10" and then create a value in the "Classified" field as "1" and select by attributes again where "Value_1" is greater than 10...and calculate the value in the "Classified" field as 10.

Run a Dissolve on the features, using the "ID" and "Classified" as the Dissolve fields, and then select to "SUM" in the stat. Use the "area_b" as the field for the sum.

This will replicate the table in the example you provided.