Intersections - Biggest Overlap Methods - Query

benedictmueller — Thu, 28 Aug 2025 10:40:12 GMT

Hey there!

In ArcPy you have the option to choose 'biggest overlap' when performing a spatial join.

I was wondering if there is any possible way to perform the same operation with the arcgis api. You have different options to perform eg a query on a feature layer with geometry filters, same for sdf.spatial.join() method. But I can only find interesect, touches, within, etc. Is there a possible workaround to maybe interesect first and then compare the geometry to calculate the bigger overlap and then only join the features of the biggest overlap?

I havent figured it out yet and would appreciate any kind of help!

Thank you in advance.

Benni xo

Re: Intersections - Biggest Overlap Methods - Query

Clubdebambos — Sat, 06 Sep 2025 11:55:45 GMT

Hi @benedictmueller,

This should get you on your way. The result is a dictionary with the key as the target oid and the value as the source oid. Code is comment, hopefully easy to follow.

from arcgis.gis import GIS from arcgis.features import FeatureLayer from arcgis.geometry import Geometry ################################################################################ ## USER INPUTS ################################################################# ## the target polygon feature layer url ply_fl_1_url = "FEATURE_LAYER_URL" ## the source polygon feature layer ## this is the one that has multiple overlaps with the one above ply_fl_2_url = "FEATURE_LAYER_URL" ################################################################################ ## REQUIRED OBJECTS ############################################################ ## we will store the target and source object ids in here results_dict = {} ################################################################################ ## ACCESS ARCGIS ONLINE ######################################################## agol = GIS("home") ################################################################################ ## CREATE FEATURE LAYER OBJECTS ################################################ ## get the target polygon feature layer as a FeatureLayer object ply_fl_1 = FeatureLayer( url = ply_fl_1_url, gis = agol ) ## get the source polygon feature layer as a FeatureLayer object ply_fl_2 = FeatureLayer( url = ply_fl_2_url, gis = agol ) ################################################################################ ## GET OID FIELDS ############################################################## ## get the target polygon feature layer oid field ply_1_oid = ply_fl_1.properties.objectIdField ## get the source polygon feature layer oid field ply_2_oid = ply_fl_2.properties.objectIdField ################################################################################ ## CREATE FEATURE SET OBJECT ################################################### ## get the target polygon feature layer as a feature set ply_1_fset = ply_fl_1.query(out_fields=[ply_1_oid]).features ## get the source polygon feature layer oid field ply_2_fset = ply_fl_2.query(out_fields=[ply_2_oid]).features ################################################################################ ## GET THE ID WITH BIGGEST OVERLAPS ############################################ ## for each polygon in the target feature layer for ply_1_f in ply_1_fset: ## create a Geometry object ply_1_geom = Geometry(ply_1_f.geometry) ## set overlap area to zero and id to None max_overlap_area = 0 max_overlap_id = None ## for each polygon in the source feature layer for ply_2_f in ply_2_fset: ## create a Geometry object ply_2_geom = Geometry(ply_2_f.geometry) ## if the target geometry overlaps if ply_1_geom.overlaps(ply_2_geom): ## then get the area of intersection overlap_area = ply_1_geom.intersect(second_geometry = ply_2_geom, dimension = 4).area ## if the overlap area is greater than previous if overlap_area > max_overlap_area: ## set the overlap area as the max max_overlap_area = overlap_area ## set the source id as the id with biggest overlap max_overlap_id = ply_2_f.attributes[ply_2_oid] ## if a max_overlap_id was found if max_overlap_id: ## add to the results dictionary {target_id : source_id} results_dict[ply_1_f.attributes[ply_1_oid]] = max_overlap_id ################################################################################ ## PRINT RESULTS ############################################################### for key,value in results_dict.items(): print(f"Target ID: {key}", f"Source ID: {value}")

All the best,

Glen

Re: Intersections - Biggest Overlap Methods - Query

benedictmueller — Mon, 08 Sep 2025 07:27:10 GMT

Puhhh 🤠 Amazing!

Thank you so much. I'll try it out! I love that this community is thriving enough to get answers on those specific questions. 💙

topic Re: Intersections - Biggest Overlap Methods - Query in ArcGIS API for Python Questions

Intersections - Biggest Overlap Methods - Query

Re: Intersections - Biggest Overlap Methods - Query

Re: Intersections - Biggest Overlap Methods - Query