Dear ArcGIS community,
I am trying to add attribute information of a soil type polygon layer to a biodiversity (output) polygon layer, where both polygon layers are different (and thus, there are different soil types in each biodiversity polygon). I only want to include the soil type that is most common in the biodiversity polygons (i.e. largest area) Thus, I thought, I would preform a Union, then calculate the area of each section and put this largest area and the soil type of this area in centroids. Then I wanted to perform a Spatial join of these centroids to the original biodiversity layer, but in a way that ONLY the soil types would be added if that soil type is most common based on the area I calculated before.
I have, however not found a way to do this (i.e. make the output soil type attribute dependent on if the corresponding area is larger than the other soil type areas within the biodiversity polygon).
What would be a way to approach this?
Thank you so much in advance, it really means a lot!
Could you add a field to both and calculate the areas on both then do your spatial join then do a selection area1 > area2 or area2 > area1
Sorry, I do not understand your answer entirely? Could you please clarify it a bit further?
Hi Jessie
I would convert my soil data to raster, and then use *Zonal statistics as
table tool* to and Majority statistics type to sect the most common soil
type in each polygon.
Regards
Mervyn
Thank you, I think this did the trick! I will check in the morning and mark the question as answered
Zonal statistics as table worked! Only, I get 18500 out of my 87.346 overlapping polygons? Is there a limit to the length of the Zonal Statistics as table tool, and can I work around this?
Hi Jessie
I have run this tool on a lot more polygons. I suspect something else my be
at play, as Dan suggests, perhaps overlapping polygons.
I gather you would have linked the zonal stats table back to your polygon
data. Select those with zero values and run zonal stats tool just on these
to see if perhaps now the balance of the units can be populated with soil
data.
Cheers
Mervyn
Curtis posted a couple of links here https://community.esri.com/message/519722#comment-519722
and the blog reference is here https://blogs.esri.com/esri/arcgis/2013/11/26/new-spatial-analyst-supplemental-tools-v1-3/
designed to handle overlaps
Thank you all so much for the help. I've tried the new zonal statistics as table 2 tool, and run a 'Find overlapping features' analysis which did not find any overlapping polygons.
Your earlier thread said you had overlapping zones. Is this not the case?
I hope you aren't confusing features in a featureclass to zones in a raster. You can have 1000 discrete polygons in a featureclass consisting of 10 classes... no overlaps... when converted to raster you will have 10 classes and all the apparent discrete zones have vanished since in a raster, it is the class that is important not their spatial position. Regiongroup is the tool to use when you convert vector polygons to raster to represent different spatial areas. Regiongroup assigns a unique value to each contiguous zone/area. It is equivalent to doing a multipart to singlepart operation in vector world.
So.. is there any overlap in the features that were converted to polygon?
You can alter the settings...within reason... that Arcmap uses for some options. You can access them from
Advanced ArcMap Settings utility—Help | ArcGIS for Desktop folder location if you have admin privileges on your machine.