Intersect

In GIS, an Intersect is an analytical operation that can be used to select any part of a feature that intersects with one or more other features. The areas of the map where all the input features intersect will create a feature as the intersect output.

The Intersect is a spatial relationship operation in which a query method is used. This query method selects features based on spatial relationships to other features. Features for selection can come from the same or different layers. Besides Intersect, other operations that use query to define spatial relationships are Containment and Proximity.

Usage Tips

Input features must be simple features that can include any combination of point, line, and polygon features. The inputs cannot be complex features like annotation features, dimension features, or network features.

If the features used have different geometry types, such as a point/line or line/polygon relationship, then the output feature will be the same as the input with the dimension geometry. For example the output of a point/line intersect operation will come out as a point shape file

Examples

Examples include selecting land parcels that intersect a proposed road or finding urban areas that intersect an active fault line. The Intersect operation can be very useful with Geocoding. Also another example of the intersect tool would be if the composite of several distribution areas of wildlife species was needed to determine a buffer zone for a proposed highway. The intersect tool could produce an output polygon with all the common areas of the species distribution polygons, subsequently excluding all areas of the distribution polygons that do not share common areas with other polygons

When two polygons are intersected, a third polygon is produced that only covers the area where the two original polygons overlap.

External links

• Intersect (Analysis). ArcGIS 9.2 Desktop Help. Retrieved 4 October 2011.