Overlay
A core spatial analysis operation in which two or more map layers are superimposed to identify relationships, intersections, or combined attributes between features. Overlay analysis is fundamental for tasks such as suitability modelling and impact assessment.
What is Overlay?
When two or more layers of geographic data are layered to merge their information, this is referred to as an overlay in GIS. Overlay facilitates the identification of connections, patterns, and intersections between various spatial features by superimposing these layers on top of one another.
Depending on how the input layers are joined or trimmed, there are several kinds of overlay operations, including intersect, union, difference, and clip, each with a distinct function. In order to combine information about soil types, vegetation, water bodies, and infrastructure and make well-informed decisions based on a variety of factors, overlay is frequently used in tasks like resource management, environmental impact assessment, and land use planning.
Related Keywords
Combining two or more map layers to find connections, patterns, and trends is known as GIS overlay analysis. Land use, soil type, vegetation, and infrastructure are examples of datasets that can be stacked to show how several aspects interact in a particular location. In order to facilitate data-driven decision-making, this approach is frequently utilized in resource allocation, environmental management, and urban planning.
A GIS technique called "spatial overlay" combines two or more map layers to examine the connections between various geographic characteristics. By stacking datasets, such as population with flood zones or land use with soil type, it facilitates improved spatial analysis and decision-making by identifying patterns, correlations, and interactions.
In order to examine links and trends, map overlay techniques in GIS entail piling several geographical datasets—such as population, soil type, elevation, and land use—on top of one another. This approach is a potent tool for spatial decision-making in resource distribution, environmental management, and urban planning since it assists in locating regions of overlap, conflict, or appropriateness.
In GIS, raster overlay combines cell-based layers to extract new spatial information, whereas vector overlay combines point, line, or polygon layers to evaluate feature interactions.