qdgc Mali

Domaine:

geospatial

Type de record:

dataset

Créateur:

Éditeur:

Hôte:

QDGC tables delivered in geopackage file
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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. Around the equator we have 360 longitudinal lines , and from the north to the south pole we have 180 latitudinal lines. Together this gives us 64800 segments or tiles covering earth.

Within each geopackage file you will find a number of tables with these names:

-tbl_qdgc_01
-tbl_qdgc_02
-tbl_qdgc_03
-tbl_qdgc_04
-tbl_qdgc_05
-etc

The attributes for each table are:

qdgc Unique Quarter Degree Grid Cell reference string
area_reference Country
level_qdgc QDGC level
cellsize degrees decimal degree for the longitudal and latitudal length of the cell
lon_center Longitude center of the cell
lat_center Latitudal center of the cell
area_km2 Calculated area for the cell
geom Geometry

Metadata
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Geodata GCS_WGS_1984
Datum: D_WGS_1984
Prime Meridian: 0

Areas are calculated with different versions of Albers Equal Area Conic using the PostGIS function st_area. For the African continent I have used Africa Albers Equal Area Conic which will look like this:
- st_area(st_transform(geom, 102022))/1000000)

Licensing
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Creative Commons Attribution 4.0 International

Conditions
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Delivered to the user as-is. No guarantees. If you find errors, please tell me and I will try to fix it.

Thankyou
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The work has over the years been supported and receicved advice and moral support from many organisations and stakeholders. Here are some of them:
- Tanzania Wildlife Research Institute
- Dept of Biology, NTNU, Norway
- Norwegian Environment Agency
- Eivin Røskaft, Steven Prager, Howard Frederick, Julian Blanc, Honori Maliti, Paul Ramsey

References
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* en.wikipedia.org
* mindland.com
* en.wikipedia.org
* safe.com

Ragnvald Larsen
Trondheim 20th of January, 2021

ragnvald@mindland.com
www.mindland.com