User:D-ECHO/Canada Land Cover

The Government of Canada publishes a Landsat-based vector landcover product (Land Cover Canada/LCC2000-V) on their Open Government website. The following guide explains how to use this data to make custom scenery for FlightGear.

License Note

Note  Please note that the author of this guide is no law professional and thus the following is only a subjective interpretation of the information.

The website states that the data is available under the Open Government License - Canada, available here. This license, in my interpretation, allows to use the data for a scenery later released under the GPL v2+, as long as you Acknowledge the source of the Information by including any attribution statement specified by the Information Provider(s) and, where possible, provide a link to this licence.. Furthermore, it states that the statement Contains information licensed under the Open Government Licence – Canada. shall be used, when there is no specific attribution statement given.. Given that I couldn't find any specific attribution statement on the product's website, I use the following statement in the scenery's README.md files in order to comply with the license requirements:

Following sources have been used:
(...)
* Landcover Data from Canadian Land Cover, Circa 2000 (Vector) - GeoBase Series, 1996-2005
	available under: https://open.canada.ca/data/en/dataset/97126362-5a85-4fe0-9dc2-915464cfdbb7 
	released under the Open Government License - Canada (https://open.canada.ca/en/open-government-licence-canada)
		Contains information licensed under the Open Government Licence – Canada.

Obtaining

In order to download the data for the area of your interest, you need to find the index for said tile. The best way for this, in my experience, is to use the Index of available files available as a .kmz file to use in Google Earth. There you can see the index to download from [3] as well as get the direct download link by clicking on the tile you want. The data comes in .zip files that need to be extracted before further use.

Processing

Splitting the shapefile

Before being able to run ogr-decode on the data, the one big shapefile that comes as the download needs to be split into the different features (Town, Heath, Farmland etc.). The catalog gives a good overview of the features along with their codes. The following, used as a linux shell script, will automatically create the required folders and split the main shapefile.

Note  This script still has potential for improvement, the catalog can help in identifying features and trying to find the best FlightGear equivalent.

mkdir lcc_water lcc_barrencover lcc_glacier lcc_rock lcc_developed lcc_heath lcc_scrub lcc_wetland lcc_herb lcc_grassland lcc_mixedcrop lcc_drycrop lcc_pasture lcc_deciduousforest lcc_evergreenforest lcc_mixedforest
for i in *.shp; do
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '20'" lcc_water/lcc_water_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '30'" lcc_barrencover/lcc_barrencover_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '31'" lcc_glacier/lcc_glacier_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '32'" lcc_rock/lcc_rock_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '33'" lcc_barrencover/lcc_exposed_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '34'" lcc_developed/lcc_developed_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '35' OR COVTYPE = '36' OR COVTYPE = '37'" lcc_barrencover/lcc_sparseveg_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '40'" lcc_heath/lcc_bryoids_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE BETWEEN '50' AND '53'" lcc_scrub/lcc_scrub_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE BETWEEN '80' AND '82'" lcc_wetland/wetland_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '83' OR COVTYPE BETWEEN '100' AND '104'" lcc_herb/lcc_herb_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '110'" lcc_grassland/lcc_grassland_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '120'" lcc_mixedcrop/lcc_mixedcrop_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '121'" lcc_drycrop/lcc_drycrop_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '122'" lcc_pasture/lcc_pasture_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE = '200' OR COVTYPE BETWEEN '220' AND '223'" lcc_deciduousforest/lcc_deciduousforest_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE BETWEEN '210' AND '213'"  lcc_evergreenforest/lcc_evergreenforest_$i.shp $i
	ogr2ogr -f "ESRI Shapefile"  -where "COVTYPE BETWEEN '230' AND '233'"  lcc_mixedforest/lcc_mixedforest_$i.shp $i
done

Note  This script assumes that there are only Canada Land Cover type .shp files in the folder it is executed in.

Decoding the shapefiles

Assuming you have used the above script, the following processes the split shapefiles using ogr-decode:

ogr-decode --all-threads --max-segment 500 --area-type Town work/Town lcc_developed             
ogr-decode --all-threads --max-segment 500 --area-type Pasture work/Pasture lcc_pasture
ogr-decode --all-threads --max-segment 500 --area-type MixedCrop work/MixedCrop lcc_mixedcrop
ogr-decode --all-threads --max-segment 500 --area-type MixedCrop work/MixedCrop lcc_drycrop
ogr-decode --all-threads --max-segment 500 --area-type DeciduousForest work/DeciduousForest lcc_deciduousforest
ogr-decode --all-threads --max-segment 500 --area-type EvergreenForest work/EvergreenForest lcc_evergreenforest
ogr-decode --all-threads --max-segment 500 --area-type MixedForest work/MixedForest lcc_mixedforest
ogr-decode --all-threads --max-segment 500 --area-type Grassland work/Grassland lcc_grassland
ogr-decode --all-threads --max-segment 500 --area-type Heath work/Heath lcc_heath
ogr-decode --all-threads --max-segment 500 --area-type Scrub work/Scrub lcc_scrub
ogr-decode --all-threads --max-segment 500 --area-type Rock work/Rock lcc_rock
ogr-decode --all-threads --max-segment 500 --area-type BarrenCover work/BarrenCover lcc_barrencover
ogr-decode --all-threads --max-segment 500 --area-type Glacier work/Glacier lcc_glacier
ogr-decode --all-threads --max-segment 500 --area-type Marsh work/Marsh lcc_wetland
ogr-decode --all-threads --max-segment 500 --area-type Lake work/Lake lcc_water
ogr-decode --all-threads --max-segment 500 --area-type HerbTundra work/HerbTundra lcc_herb

Afterwards you can run tg-construct as normal.

Suggested additional data

Given the high accuracy of OSM Coastline data as well as the lack of linear features in Canada Land Cover data, the following features should be additionally used from OpenStreetMap:

• Default ( OSM Landmass, either from OSM Data Land Polygons or extracted from your area's openstreetmap file with the tag natural=coastline/place=island/place=islet )
• Roads
• Rivers/Streams

Additionally, as Land Cover Canada is very unspecific about developed areas (there is only 33 Exposed Land and 34 Developed), you might want to use OSM data for

• Residential Areas
• Commercial Areas
• Industrial Areas
• Transportation Areas (railway, ports)
• Mines
• Landfills

depending on the quality of OSM coverage in your region of interest

LCC to FlightGear mapping

This table shows which area codes and descriptions are mapped to which material names in FlightGear. It is basically a condensed version of the information in the above scripts as well as the code descriptions from the catalog PDF file. Bold Material names are used by the scripts above.

Code	Description	FlightGear Material
0 / 10 / 11 / 12	Unusable (Feature Catalog describes it as Unclassified, Cloud or Shadow)	none (could be used as Default in case OSM Coastline isn't used)
20	Water	InlandWater / Lake
30	Barren	BarrenCover
31	Snow and Ice	Glacier
32	Rock and Rubble	Rock
33	Exposed Land	BarrenCover
34	Developed	Town
35 - 37	Sparse Vegetation	BarrenCover
40	Bryoids	Heath
50 - 53	Shrubland	Scrub
80 - 82	Wetland	Marsh
83, 100 - 104	Herbs	HerbTundra
110	Grassland	Grassland
120	Cropland	MixedCrop
121	Annual Cropland	DryCrop
122	Pastures	Pasture
200	Forest	DeciduousForest
210 - 213	Coniferous Forest	EvergreenForest
220 - 223	Deciduous Forest	DeciduousForest
230 - 233	Mixed Forest	MixedForest