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The shapefile format was introduced with ArcView GIS version 2 in the early 1990s. It is now possible to read and write geographical datasets using the shapefile format with a wide variety of software. The shapefile format stores the geometry as primitive geometric shapes like points, lines, and polygons.
Online collection of all digital USGS 1:24K scale topographic maps (as well as various other GIS data) covering the United States, available as a free download. NPScape United States Department of the Interior National Park Service NPScape is a landscape dynamics monitoring project that provides landscape-level data, tools, and evaluations for ...
QGIS is a geographic information system (GIS) software that is free and open-source. [2] QGIS supports Windows, macOS, and Linux. [3] It supports viewing, editing, printing, and analysis of geospatial data in a range of data formats. Its name comes from an abbreviation of its previous name, Quantum GIS.
Shapefiles : are a data exchange format created by ESRI and one of the most widely used GIS/geodata formats. One "shapefile" usually include four different files : .shp, .shx, .dbf, .prj. First three files must all be present in order to use the data. Each shapefile can hold only one geometry type.
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 ...
The origin of the geodatabase was in the mid-1990s during the emergence of the first spatial databases.One early approach to integrating relational databases and GIS was the use of server middleware, a third-party program that stores the spatial data in database tables in a custom format, and translates it dynamically into a logical model that can be understood by the client software.
GML defines features distinct from geometry objects. A feature is an application object that represents a physical entity, e.g. a building, a river, or a person. A feature may or may not have geometric aspects. A geometry object defines a location or region instead of a physical entity, and hence is different from a feature.
Geodesy Subcommittee of OGP (2012), EPSG Area Polygons, (International Association of) Oil and Gas Producers (OGP), archived from the original on 2013-05-31 (Download Shapefile 2012.11 [permanent dead link