Spatial data and its types

By Omar Kawach

Spatial data

Spatial data have two main components that set them apart from regular data, making them suitable for mapping:

Spatial data can be categorized into two types: raster and vector.

Raster data are described as a grid of cells (rows and columns), similar to pixels in pictures.

Each cell contains a value representing a specific characteristic of a studied geography
Commonly used for continuous data, like land use, temperature or elevation (e.g., Digital Elevation Models or DEMs, which consist of elevation values)
Raster data are stored as a grid of cells, with each cell having a unique value based on its x, y, and z coordinates within the grid
Can be either continuous (progressive, varying data) or discrete (thematic or categorical)
Rectangular tessellated rasters are most commonly used due to their mathematical simplicity
Examples of raster data include satellite images or aerial photos
Most commonly seen in the GeoTIFF file format

Vector data are represented as points, lines, and polygons.

Commonly used for representing discrete or categorical data, such as political boundaries, roads, or land cover
Stored as sets of x, y coordinate pairs defining point locations, or as series of coordinates defining vertices of lines or polygons
Can be categorized into 0-dimensional, 1-dimensional, and 2-dimensional forms (geometric primitives). In the 0th dimension, coordinate points exist independently. In the 1st dimension, two points can form a line. In the 2nd dimension, three or more lines can be joined to create a polygon
Vector data allows for more efficient storage and manipulation
Can convert vectors to raster and vice versa using specialized software (e.g., ArcGIS Pro, and QGIS)
Common data formats include CSV, KML (Google), GeoJSON, and Shapefile (Esri)

Comparing real world data to types of spatial data

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0 of 3 correct

Which is preferred for representing continuous data such as elevation? (Hint: you want the data with the more detailed representation of terrain)