GEOG 3315 - Module 2

Geospatial Data Model

A formal means of representing spatially referenced information, simplifying physical entities and conceptualizing reality.

Object

The part of a geospatial data model that stores the geometry of the spatial phenomenon being modeled.

Attribute

Descriptive information related to the object part of a geospatial data model.

Discrete Spatial Phenomenon

Individually distinguishable entities with well-defined boundaries, such as streams or roads.

Continuous Spatial Phenomenon

Data that exists between observations and cannot be isolated as individual entities, such as temperature or elevation.

Vector Data Model

Defines discrete objects using points, lines, and polygons, each composed of coordinates and attributes.

Point

A single coordinate pair defining a location, considered to have no dimension in GIS.

Line

Defined by an ordered set of coordinates, with nodes where lines begin or end and vertices where lines change direction.

Polygon

Formed by connected lines where the start and end points have the same coordinate, creating an interior region.

Raster Data Model

Represents continuous objects using a regular set of cells or pixels in a grid pattern, each cell containing a single value.

Raster Resolution

The cell size of each cell in a raster, indicating how much area on the ground each cell covers.

Triangulated Irregular Network (TIN)

A network of triangles connected to create a 3-D surface, preserving input measurement points and accommodating different sampling densities.

Attributes (in GIS)

Non-spatial characteristics that describe spatial entities, typically arranged in tables with rows representing entities and columns representing attributes.

Coordinate System

Sets of geographic grids that provide a structured way of communicating geographic location using x,y coordinates.

Metadata

Information that describes a dataset, including its content, author, creation date, and intended use, helping to assess the quality and appropriateness of the data.

Domains

Constraints on valid values for a particular field in a dataset, helping to prevent errors during data entry.

Subtypes

Subsets of features sharing the same attributes, used to categorize features within a dataset.

Topology

The spatial relationships between features, ensuring connectedness, adjacency, and proximity are maintained in GIS data.

Archiving

Recording and accessing changes to data over time, allowing for temporal analysis of how features and attributes have changed.

ArcGIS Online

A platform for creating, storing, and sharing GIS data and content, providing access to a library of authoritative data.

Geocoding

The process of converting addresses into geographic coordinates, allowing for spatial analysis and mapping.

Feature Dataset

A collection of related feature classes that share the same coordinate system, used to organize and manage GIS data.