What does the "intersect" selection method do in GIS?

The "intersect" selection method in GIS identifies and selects features that share any portion of space with the source layer. This means that if a feature from another layer touches, overlaps, or crosses into the area defined by the source layer, it will be included in the selection. This method is commonly used to analyze relationships between different geographic features, allowing for complex spatial analyses that consider how various datasets interact with one another.

For example, if the source layer consists of a polygon representing a watershed, using the "intersect" method would select any polygons from other layers representing land use, protected areas, or other geographical features that are either inside, overlap, or simply touch the edges of the watershed polygon. This capability is critical in many applications, such as environmental impact assessments, land management, and urban planning, where understanding spatial relationships is key to effective decision-making.