Proposal:Landcover
| Landcover key | |
|---|---|
| Proposal status: | Proposed (under way) |
| Proposed by: | dieterdreist |
| Tagging: | landcover=* |
| Applies to: | |
| Definition: | Key landcover to enhance description possibilities for areas |
| Statistics: | |
| Draft started: | 2010-11-16 |
| RFC start: | 2010-11-16 |
Summary
- Wikipedia : Land cover is the physical material at the surface of the earth. .... Land cover is distinct from land use, despite the two terms often being used interchangeably. Land use is a description of how people utilize the land and of socio-economic activity.
- NOAA : Land cover indicates the physical land type such as forest or open water whereas land use documents how people are using the land.
- Michigan State University :
- Land use is commonly defined as a series of operations on land, carried out by humans, with the intention to obtain products and/or benefits through using land resources.
- Land cover is commonly defined as the vegetation (natural or planted) or man-made constructions (buildings, etc.) which occur on the earth surface. Water, ice, bare rock, sand and similar surfaces also count as land cover.
This proposal was created in 2010 to introduce the key landcover=* to be used for describing the physical cover of an area (grass, trees, water, etc) as distinct from landuse=* which is used to describe the human use of the area and also distinct from geographical features as described with natural=* (Note that since 2010 some values have been introduced into the natural key which do not fit into the definition of geographical feature, e.g. "natural=mud"). These concepts are orthogonal, for example both, a sports pitch and a car park, can be covered with grass or asphalt; equally one can have a landcover of grass within a park, a garden, a road verge, an aerodrome or a meadow for grazing cows, which are all different landuses.
This distinction reflects the two traditional branches of geography : Physical geography and Human geography. Clearer tagging of the form proposed will facilitate more rigorous scientific uses of OSM in the fields of biology, geography and geology. It will enable scientists to contribute their data to OSM, as well as the use of OSM as a scientific tool.
The current situation
Landuse information is already provided, mainly by landuse=*, but landuses are also covered by amenity=* (car parks, schools, universities, hospitals etc) and by leisure=* (park, recreation ground etc).
Landcover information is partly available in OSM, but is spread across many keys - such as landuse, natural and surface. Some values of landuse are actually landcover, for example landuse=grass. Since 2010, the landcover key has gained some followers, and while there is no principal app (editing or rendering) supporting the tag, there is some usage. A missing clear distinction between landuse and landcover leads to different interpretations of some landuse tags (e.g. landuse=forest) where some users tend towards a use-related interpretation while others use the tag mainly related to physical appearance.
The current tagging makes it difficult to tag some features. For example, a military area which is covered with grass can't be tagged both with landuse=military and with landuse=grass (e.g. the tag leisure=park is definitely wrong). Meanwhile, the official definitions for the tags landuse=forest and natural=wood have been "downgraded" to mean nothing different from "there are some trees here".
This proposal aims to provide a consistent structure to resolve some of the semantic inconsistencies in the tagging scheme and to ensure that it is always possible to provide both: a landuse and a landcover for every location.
As of January 2016, landcover=* had 17,912 uses according to taginfo. In September 2018 this had increased to 67,000. In March 2019 usage was 170,000 objects, of which 96,000 objects were found to be from an organized mapping effort in Paraguay[1] (resulting in 74,000 non-related objects).
The proposal
The existing landuse=* tag would be retained for human uses of land, including: Economic activities, transportation, construction, tourism, history and culture, industry. Most of the landuse=* definitions currently in use are indeed already a part of this domain, but some tags will need to be transitioned to reflect the more systematic tagging scheme. A 'landuse=highway' should be added to cover land forming part of a road (including carriageway, footways and verges). The 'landuse=grass' tag could be deprecated with landcover=grass taking its place.
Natural key
The natural key could also be reviewed. Most of the values there actually describe geographic features, as distinct from landcover or landuse. but there is also some exceptions that might be better suited in landcover, for example natural=sand and natural=mud.
Landcover tags and related tags
The landcover key with the following values:
| tag | definition | taginfo counts |
|---|---|---|
| landcover=greenery | for any area covered with greenery, regardless of it being on a roundabout, along a street or in a park/garden, etc. | |
| landcover=trees | for any area covered with trees, regardless of it being natural or not, in a forest or in a park/garden, etc. | |
| landcover=grass | for any grass covered area | |
| landcover=flowers | for any flowers covered area | |
| for any water covered area, use natural=water | ||
| landcover=sand | for any sand covered area | |
| landcover=bare_rock | uncovered, bare rock, at most sparsely vegetated | bedrock ; bare_rock |
| landcover=gravel | gravel pebblestone scree | |
| landcover=loam | mixture of sand, silt and clay (deprecates natural=mud), without or with sparse vegetation | |
| landcover=compacted_hardcore | a surface of hardcore material which has either been compacted on purpose or through use | |
| landcover=ice | for areas covered the whole year with ice (see also natural=glacier for ice masses that move on their own) |
While duplicate tagging isn't a problem as such, the following tags will often not imply more meaning than the landcover tag:
- natural=mud (e.g. landcover=ground, bare_ground)
- natural=sand (same meaning as landcover=sand)
- landuse=grass (while originally defined for grass areas part of a highway, it is now often used as a generic grass area: landcover=grass)
- surface=* Surface is mainly used for line features, e.g. to assist with routing.
The following tags are extremely established and very unlikely to change:
Applies to
Areas, can and should be combined with geographical features (natural) and landuse.
Rendering
It is up to the renderers what they display, at which zoomlevel, and if they focus on landuse=*, landcover=*, or both or something else.
Comments
Please use the discussion page.
Also see some comments here:
- RFC: new key Landcover - RFC on tagging mailing list
- Landcover proposal update 2014