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Roads dataset from South Australian Government Data Directory. Shapefile (GIS) dataset of every sealed and unsealed road in the state, and has been recently created and updated (2013). Data includes road names, route numbers, and class (Highway, Arterial, etc.). The license is CC-BY-3.0-AU, so it can be used to create maps.
U.S. Gazetteer, TIGER/Line shapefiles, census data. National Historical Geographic Information System: NHGIS provides free of charge, aggregate census data and GIS-compatible boundary files for the United States between 1790 and 2012. Atlas of Historical County Boundaries Project (AHCBP)
In spatial analysis, four major problems interfere with an accurate estimation of the statistical parameter: the boundary problem, scale problem, pattern problem (or spatial autocorrelation), and modifiable areal unit problem. [1] The boundary problem occurs because of the loss of neighbours in analyses that depend on the values of the neighbours.
The shapefile format is a geospatial vector data format for geographic information system (GIS) software.It is developed and regulated by Esri as a mostly open specification for data interoperability among Esri and other GIS software products. [1]
[12]: 218 A topology rulebase is a list of desired topology rules used to enforce spatial integrity in spaghetti data, such as "county polygons must not overlap" and "state polygons must share boundaries with county polygons." [13] Vector datasets usually represent discrete geographical features, such as buildings, trees, and counties.
A software capable to read coordinate reference systems in WKT 2 format can also read many (but not all) equivalent systems in WKT 1 format. [9] Some caveats exist, notably the removal of the TOWGS84 element [10] which is replaced by the BOUNDCRS element.
The ARC/INFO Coverage data structure (1981), a topological data model based on POLYVRT. Topology was a very early concern for GIS. The earliest vector systems, such as the Canadian Geographic Information System, did not manage topological relationships, and problems such as sliver polygons proliferated, especially in operations such as vector overlay. [9]
Five million place names, political boundaries, latitude/longitude lines, and other data can be displayed. WorldWind.NET provided the ability to browse maps and geospatial data on the internet using the OGC's WMS servers (version 1.4 also uses WFS for downloading place names), import ESRI shapefiles and kml/kmz files. This is an example of how ...