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This is a list of GIS data sources (including some geoportals) that provide information sets that can be used in geographic information systems (GIS) and spatial databases for purposes of geospatial analysis and cartographic mapping. This list categorizes the sources of interest.
As the GIS industry grew to incorporate more casual users, the inherent complexity of the coverage data structure became a concern. When Esri released ArcView GIS 2.0 in 1992, it introduced the new shapefile format for vector data. This was a much simpler data model, eliminating features such as topology, but was still a georelational design.
Geographic information system (GIS) is a commonly used tool for environmental management, modelling and planning. As simply defined by Michael Goodchild, GIS is as "a computer system for handling geographic information in a digital form". [68] In recent years it has played an integral role in participatory, collaborative and open data philosophies.
Time-stamped features, in which the dataset includes features valid at a variety of times, with each feature stamped by the time during which it was valid (i.e., by "start date" and "end date" columns in the attribute table.). Some GIS software, such as ArcGIS Pro, natively supports this model, with functionality including animation.
Location information (known by the many names mentioned here) is stored in a geographic information system (GIS). There are also many different types of geodata, including vector files, raster files, geographic databases, web files, and multi-temporal data.
Two strategies have been used to integrate the geometry and attributes into a single vector file format structure: [13] A georelational format stores them as two separate files, with the geometry and attributes of each object being linked by file ordering or a primary key. This was most common from the 1970s through the early 1990s, because GIS ...
Attributes, characteristics of a feature other than location, often expressed as text or numbers; for example, the population of a city. [19] In geography, the levels of measurement developed by Stanley Smith Stevens (and further extended by others) is a common system for understanding and using attribute data.
Simple Features (officially Simple Feature Access) is a set of standards that specify a common storage and access model of geographic features made of mostly two-dimensional geometries (point, line, polygon, multi-point, multi-line, etc.) used by geographic databases and geographic information systems.