What does the symbol ∪ indicate in geographic data?

The symbol ∪ in geographic data signifies "union," which is a key operation in geographic information systems (GIS) and set theory. The union operation combines two or more geographic datasets, creating a new dataset that encompasses all the features from the input datasets.

For instance, if two different layers represent different land use types, performing a union on these datasets would create a comprehensive layer that includes all areas represented in both original datasets. This operation is particularly useful for identifying overlaps in datasets, creating new geographical features, and how different spatial features can coexist.

Understanding this concept is critical in GIS analysis, as it allows professionals to merge data effectively for various applications, such as urban planning, resource management, and environmental assessments.