Descriptive Data
Tabular data describing the geographic characteristics of map features. Can include numbers, text, images, and CAD drawings about features. ARC/INFO stores descriptive data in feature attribute tables and in related tables.
Descriptive data stored in rows and columns in a database that can be linked to spatial data.
Tax Lot ...
Geographic Database Efficently stored and organized spatial data and possibly related descriptive data.
photomap (photographic map) Map made by adding marginal information, descriptive data, and a reference system to a photograph or assembly of photographs.
Most systems distinguish between the management of geometrical and descriptive data. For performance reasons, geographical data are mainly stored in proprietary databases.
Attribute (tabular data) is descriptive data that GIS links to map features.
Thus, content may manifest as descriptive data stored in Web-accessible databases, or as markup within documents (particularly, in Extensible HTML (XHTML) interspersed with XML, or, more often, purely in XML, ...
" GIS can storehouse tremendous volumes of descriptive data and overlay a myriad of maps for their coincidence. It has powerful tools for expressing the spatial interactions among mapped variables.
Variable length fields are used or highly variable data such as descriptive data. Database data is normally access either by sequential or random access methods. Sequential access is accomplished when data is arranged in contiguous, linear fashion.
A GIS is basically a descriptive database of the earth (or a specific part of the earth). GPS tells you that you are at point X,Y,Z while GIS tells you that X,Y,Z is an oak tree, or a spot in a stream with a pH level of 5.4. GPS tells us the "where".
Geographic database - "A collection of spatial data and related descriptive data organized for efficient storage and retrieval by many users" (GIS Development, n.d.).
Relational Join The process of connecting two tables of descriptive data by relating them by a key item, then merging the corresponding data. The common key item is not duplicated in this process.
The model has three main components: the semantic - the descriptive data of interest, the geometry - point, line, polygon, raster, etc. and the graphic representation - color, texture, etc.
 See also: Relation, Information, Object, Database, Area
|
