Polygon overlay


Polygon overlay is a process in Geographic Information Systems (GIS) where two or more spatial datasets are combined to create a new layer that contains the overlapping areas. This is achieved by comparing the boundaries of each polygon in the datasets and creating a new shapefile or layer that only includes the portions of the polygons that overlap.

Polygon overlay is a common operation in GIS used to analyze and display the relationships between different geographic features. This technique is used to combine two or more datasets and create a new layer that shows the overlapping areas. The resulting layer can be used to study patterns, trends, and relationships between different features.


  • Environmental studies: Overlaying maps of vegetation, soil types, and topography can help identify areas of high ecological significance, such as wetlands or wildlife habitats.
  • Land use planning: Overlaying maps of land ownership, zoning, and transportation networks can help identify areas suitable for development or protected areas.
  • Disaster response: Overlaying maps of natural hazards, such as floods or wildfires, with maps of population density and infrastructure can help emergency responders plan evacuation routes and allocate resources.
  • Marketing and sales: Overlaying demographic data, such as income levels and education, with maps of retail locations can help businesses identify areas with high potential for sales.
  • Crime analysis: Overlaying maps of crime incidents with maps of demographic data can help identify patterns and hotspots of criminal activity.