topic Re: Calculate the area of intersection between two features in Geodatabase Questions

Calculate the area of intersection between two features

HaniDraidi — Fri, 12 Feb 2016 11:46:07 GMT

Is there a way to derive the area of intersection resulted by the intersection of two features after performing "SHAPE.StIntersects()"?

Re: Calculate the area of intersection between two features

WesMiller — Fri, 12 Feb 2016 13:23:32 GMT

If you perform an Intersect—Help | ArcGIS for Desktop on two polygon feature classes and store the results in a geodatabase the area will be calculated for you. However you can also use the Add Geometry Attributes—Help | ArcGIS for Desktop to calculate the areas or calculate geometry on a double field.

Re: Calculate the area of intersection between two features

NeilAyres — Fri, 12 Feb 2016 14:25:05 GMT

You don't say what sort of db you are using here. In sde the geometry function is ST_Intersect (I think).

This can return a query result, you would have to insert it into another feature, then calculate the area of that piece if geometry, as Wes says.

Otherwsie just use the Intersect tool, which creates that other feature as part of its output.

Re: Calculate the area of intersection between two features

VinceAngelo — Fri, 12 Feb 2016 15:27:44 GMT

MIcrosoft documentation or forums might be a better place to research the proper use of Microsoft SQL Server native functions. The basic process is the same as with the Esri-written ST_Intersects and ST_Area functions used in non-Microsoft databases, but the SQL-Server syntax has it's own quirks (including case sensitivity), so it's best to get your information from the capability provider.

- V

Re: Calculate the area of intersection between two features

JoshuaBixby — Sun, 12 Dec 2021 09:56:28 GMT

It appears you are using SQL Server native spatial types. That said, it is best to be explicit and not make people guess.

First, STIntersects isn't the method you need. It is a check of intersection and returns a SqlBoolean.

Below is an example using SQL Server native spatial types to retrieve the intersecting area of 2 polygons:

Declare @g1 geometry;
Declare @g2 geometry;

SET @g1 = 'POLYGON((0 0, 10 0, 10 10, 0 10, 0 0))'
SET @g2 = 'POLYGON((5 5, 15 5, 15 15, 5 15, 5 5))'

SELECT @g1.STIntersection(@g2).STArea()

Re: Calculate the area of intersection between two features

HaniDraidi — Fri, 12 Feb 2016 16:37:10 GMT

I am using Microsoft SQL Server

Re: Calculate the area of intersection between two features

HaniDraidi — Fri, 12 Feb 2016 16:46:20 GMT

Thats exactly what I'm looking for

Many thanks Joshua!