Which method is used to combine multiple datasets in GIS analysis?

The overlay method is fundamental in geographic information systems (GIS) for combining multiple datasets. This technique allows users to superimpose layers of information to analyze the spatial relationships and interactions between different data sets. For example, overlay can be used to analyze land use in conjunction with environmental data, enabling the identification of areas vulnerable to flooding or pollution.

Overlay works by aligning datasets that share a common geographic space and allows for the creation of new data based on the combined attributes of the overlapped layers. Through this method, GIS professionals can derive more complex insights, such as finding out which land parcels are at risk by overlaying flood risk maps with the land ownership maps.

In contrast, aggregation involves summarizing data points into a single entity, classification refers to categorizing data into groups based on attributes, and segmentation pertains to dividing a dataset into meaningful parts. Although these methods are useful for various GIS tasks, they do not inherently combine datasets in the way that overlay does.