- OpenStreetMap -

State of the land-use mapping in Belgium

26.10.2017 - FOSS4G.be - Bxl

Julien Minet

Champs-Libres.coop

This presentation and scripts are available on github.com/nobohan/OSMLanduseAnalyzer.

Why?

Objectives

1. Quantitative assessment of land-use/land-cover mapping in OSM in Belgium
2. Discuss some cases/issues
GOAL: Some Belgian conventions on land-use mapping with OSM in Belgium

Quantitative assessment of land-use/land-cover mapping

[Quantitative assessment of land-use/land-cover mapping]

Methodology

OSM data was download from geofabrik on the 10/10/2017.

[Quantitative assessment of land-use/land-cover mapping]

Methodology

Selection of tags (key=value) for "land-use"

Tag list inspired by the "land-use" preset of OSM-Bright


waterway=riverbank;
landuse=basin,reservoir,park,forest,residential,retail,commercial,industrial,railway,cemetery,grass,farmyard,farm,farmland,wood,meadow,village_green,recreation_ground,allotments,quarry,orchard,vineyard,greenhouse_horticulture;
leisure=park,garden,playground,golf_course,sports_centre,pitch,stadium,common,nature_reserve;
natural=wood,land,scrub,wetland,water,heath,grassland;
highway=pedestrian,footway;
amenity=university,school,college,library,fuel,parking,cinema,theatre,place_of_worship,hospital;
place=island;
aeroway=aerodrome,helipad,apron

[Quantitative assessment of land-use/land-cover mapping]

Results

Global share of "land-use" tags in Belgium

Note that many "land-use" polygons superimpose to each other.

[Quantitative assessment of land-use/land-cover mapping]

Results

Share of agricultural "land-use" tags in Belgium

[Quantitative assessment of land-use/land-cover mapping]

Results

Part of forested "land-use" that is defined by leaf_type|leaf_cycle in Belgium

The deprecated `wood=*` tags are not considered here.

[Quantitative assessment of land-use/land-cover mapping]

Results

Total coverage of "land-use" tags by provinces in Belgium

OSM land-use mapping issues

[OSM land-use mapping issues]

Should we merge land-use nodes to other (linear) features?

See this discussion https://help.openstreetmap.org/questions/17501/when-mapping-polygons-surrounded-by-streets-should-they-share-nodes-or-be-traced-separately on the OSM forum

PROS	CONS
This allow more features to be mapped in the future (hedges, ditches, ...) Geographic features are digitalized with keeping their real ground footprint	The "OSM land-use" database is not continuous

PROS

CONS

This allow more features to be mapped in the future (hedges, ditches, ...)

Geographic features are digitalized with keeping their real ground footprint

The "OSM land-use" database is not continuous

[OSM land-use mapping issues]

Should we superimpose "land-use" features?

See this discussion on the OSM forum?

https://help.openstreetmap.org/questions/17874/overlapping-land-use-cf-residential-and-forest

Why not? (it depends)

[OSM land-use mapping issues]

`natural=wood` vs 'landuse=forest' for mapping forests in Belgium

See this discussion on the OSM forum?

`landuse=forest`

[OSM land-use mapping issues]

`landuse=farmland` vs 'landuse=meadow' for mapping meadows in Belgium

Arable land: landuse=farmland + crop=*

Grazed meadows: landuse=meadow + meadow=agricultural + animal=yes

Hay meadows: landuse=meadow + meadow=agricultural + crop=grass

[OSM land-use mapping issues]

Better describe leaf_type | leaf_cycle in forests?

[OSM land-use mapping issues]

Confusion between land-use & land-cover in OSM

e.g., landuse=grass

landcover=* tags are not rendered

natural=* tags are often pure land-use (and not natural features, at least in Belgium).

Perspectives: OSM land-use/land-cover database

Collaboration between crowdsourced geodata collection and professional land-use mapping project/agencies would be welcome.
At the long term, frequently updated information could be used for historical reconstruction of land-use --> In the future, would it be possible to use OSM to study land-use/land-cover changes?
Use OSM as an auxilliary data for updating land-use/land-cover maps. See the research project Landsense.eu
In 20 years, OSM as an historic db for land-use/land-cover changes

References

Some scientific articles on the issue:

Assessment of land-use classification and accuracy in OSM in Vienna, Austria : Arsanjani et al., Toward mapping land-use patterns from volunteered geographic information, International Journal of Geographical Information Science, 2013 [link]
Comparison of OSM against Corine Land Cover in Portugal : Estima & Painho, Exploratory analysis of OpenStreetMap for land use classification, 2013 [link]
Accuracy of natural features in OSM (several countries): Winstanley, A study of data representation of natural features in OpenStreetMap, Proceedings of GIScience, 2010 [link]
Production of a land-cover map from OSM and automatic gap-filling with remote sensing data: Schultz et al., Open land cover from OpenStreetMap and remote sensing, International Journal of Applied Earth Observation and Geoinformation, 2017. [link]