QDGC - Quarter Degree Grid Cells (or QDS - Quarter degree Squares) are a way of dividing the longitude latitude degree square cells into smaller squares, forming in effect a system of geocodes. QDGC represents a way of making (almost) equal area squares covering a specific area to represent specific qualities of the area covered. The squares themselves are based on the degree squares covering earth. Providing prepared files for this purpose makes it possible to use the standard with a proper reference. The concept is important for biodiversity information management processes - often more generally refered to as spatial data infrastructures (SDI).

• Upload and convert a .dbf-file
• Download and run lonlat2qdgc.exe to convert a .dbf-file

• Web Mapping Biodiversity
• Updating QDGC
• QDGC level 1 files
• QDGC level 2 files
• QDGC basics(power point presentations etc...)

Upload and convert

By: ragnvald  on: Sun 13 of Dec., 2009 14:00 UTC  (1094 Reads)

We are now testing out an upload and convert service on this website. This means that one of our pages will let you upload a .dbf-file with LON/LAT columns and then download a file with a QDGC string. We have dealt with some initial problems, and the service now seems to be up and running, although we might still have the odd error. In case the service, crashes there is a restart every hour.

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Updated lonlat2qdgc tool

By: ragnvald  on: Tue 01 of Dec., 2009 16:19 UTC  (448 Reads)

The lonlat2qdgc tool has been updated. The tool creates a qdgc reference string based on positional data. An incompatibility in one of the libraries led to problems for some users. The new version is available for download on this website.

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Article in African Journal of Ecology

By: ragnvald  on: Sat 21 of Mar., 2009 21:54 UTC  (880 Reads)

An article on Quarter Degree Grid Cells has been published in the African Journal of Ecology. DOI: 10.1111/j.1365-2028.2008.00997.x

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Paper in progress - current article overview

By: System Administrator  on: Thu 17 of Apr., 2008 19:50 UTC  (987 Reads)

A key paper on the extension of QDGC is under preparation and will probably be presented a bit later this year. The paper will focus on describing historical use of QDGC as presented by the Avian Demography Unit at the University of Cape Town, South Africa. Furthermore the paper will describe an extension of the QDGC which is suitable for global use. In the meantime I would encourage reading up on articles using the original QDGC. This article represents a short list.

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National level QDGC files for Africa

By: ragnvald  on: Tue 30 of Oct., 2007 22:46 UTC  (2860 Reads)

This is an announcement of the availability of Quarter Degree Grid Cells (QDGC) on a national level for African countries.

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