GEOG 3315 - Module 6

Geospatial Data Analysis

The application of operations to manipulate or calculate coordinates and/or related attribute data to solve spatial problems.

Spatial Selection

A geospatial analysis technique that identifies features based on spatial relationships such as adjacency, intersect, containment, and distance.

Adjacency

Identifies features that share a boundary segment with the input feature.

Intersect

Identifies features that touch or overlap the input feature.

Containment

Identifies features that are completely within or completely contain the input feature.

Distance

Identifies features that are within a set distance of an input feature.

Buffer

A region that is less than or equal to a specified distance from one or more input features, used to identify areas or objects inside or outside the threshold distance.

Dissolve Operation

Combines similar features within a data layer based on a shared attribute, merging them into a single feature.

Overlay Operations

Involves combining spatial and attribute data from two or more spatial data layers, stacking the data to find overlapping areas.

Clip Operation

An overlay operation that defines the area for which features will be output based on a clipping polygon, similar to using a cookie-cutter on dough.

Intersection Operation

Combines data from two or more input layers, but only for regions where all input layers contain data.

Union Operation

An overlay operation that includes all data from all input layers, combining all attributes and geometry without discarding any geographic data.

Vector Overlay

Combining point, line, or polygon geometry and their associated attributes, creating new geometry and a new output geospatial data set.

Sliver Polygons

Small, typically insignificant polygons created when input features have slightly different geometry, often due to different scales or data sources.

Re-project

The process of converting data sets to the same coordinate system to ensure accuracy in overlay operations.