User:Rudolf/draft landcover

Proposal

landcover=* is the observed (bio)physical cover on the earth's surface.

It describes what you can actually see in bird's eye view or in aerial photography, independently if it is biological or geological. This can be the tallest plants (e.g. trees) or the naked surface (e.g. bare rock).

landcover=* is dedicated to describe the whole earth's surface with only one key. It is not dedicated to detailed mapping in urban environments, although you can do it.

All areas in the landcover features of natural=* will be transfered to landcover=*. Alternatively this tags can be tagged double, with a lot of redundand data.

The tags landuse=grass, landuse=forest and landuse=railway will be transfered to landcover=*.

The main concept relates to the NLCD92 - National Land Cover Database (table). Some values relates to the LCCS - Land Cover Classification System (table).

Rationale

• Landcover is what you can actually see in bird's eye view or in aerial photography. It is what faces the sky: Tallest plants (not one by one), barren soil, barren mountain rocks etc. Landcover can only be tagged on areas, not on ways or nodes. It incorporates the whole earth's surface, without oceans.

• Surface is the upper layer of the planet if vegetation etc. is hypothetically stripped off. This may be a natural surface such as rock, sand, soil, water or a man made surface such as asphalt, concrete, paving stones, or pebble stones. Surface is mostly tagged on mad-made barrent things such as the active parts of roads, plazas, sports pitches etc., but may also be tagged where the surface beneath a landcover is unusual, such as trees growing on sand. Surface can be tagged on areas but would mostly be used on ways and points that already carry a primary tag which makes it relevant. For instance a way tag as a highway will often have a surface to indicate if and how it is paved.

• Landuse is the how an area is used, which may or may not related to its landcover and/or surface. Land use tags should be used where the use is known and not implied by some other tag. Common uses in topography maps are residential area, cemetery, cropland, meadow, orchard and vineyard.

The current situation

Today OSM lacks a consistent tagging scheme for the earth's surface.

Landcover information is already provided, mainly by natural=* and landuse=* and surface=*.

natural=* is a mishmash of landcover features (e.g. wood) and landscape features (e.g. single tree, tree_row). This is disturbing to a simple and consistent tagging of the earth's surface.

natural=* contains some overlapping features such as natural=sand/natural=beach or natural=bedrock/natural=bare_rock/natural=rock or natural=grassland/natural=fell.

There are ambiguous tags, e.g. natural=fell describes a form of vegetation and also mountain peaks, natural=rock describes areas of rocks and is used on 140.000 nodes.

There are undocumented tags, e.g. natural=mud.

There are similar-sounding tags, e.g. natural=bedrock, natural=bare_rock, natural=rock, natural=stone.

There are many features in water=* that don't belong to natural=*, eg. reflecting_pool, reservoir, canal, lock, moat, wastewater. We have water=reservoir and landuse=reservoir.

There is a problematical determination between natural=wood and landuse=forest.

There is no tag for areas of perennial ice/snow on mountain tops or in the polar area.

There is no tag for all areas including infrastructure features.

The current tagging makes it impossible to tag some features. For example, a military area which is covered with woodland can't be tagged both with landuse=military and landuse=forest.

How to map

All landcover features are areas and can either be created as a closed way or as multipolygon.

Gaps between neighbouring areas are to be avoided.

There are 8 main values with 8 sub-keys. There are in total 36 subcategories.

Landcovers, incorporating the whole earth's surface

Tag	Description	Subtags	Description	Picture	Deprecate
landcover=water	Area of open water or permanent ice/snow cover.	water=lake	Area of water surrounded by land.		natural=water natural=glacier
		water=river	Area of a wide river.
		water=reservoir	Artificial lake, used to store water.
		water=canal	Area of a man-made channel for water.
		water=ice	Area characterized by year-long surface cover of ice and/or snow. Glaciers, mountain tops, polar ice.
		water=*	others
landcover=wetland	Area where the soil is periodically saturated with or covered with water.	wetland=swamp	Swamps are wooded wetlands that are often flooded for a portion of the year. Swamp vegetation is dominated by trees and tall shrubs.		natural=wetland
		wetland=marsh	Marshes are wetlands that are periodically or permanently flooded with water. Marsh vegetation typically consists of non-woody plants such as cattails, rushes, reeds, grasses and sedges
		wetland=bog	Bogs are peat-filled depressions that receive their water and nutrients from rainfall. Peat consists of partially decomposed plants. They are frequently covered in shrubs rooted in the sphagnum moss and peat.
		wetland=fen	Fens are located in areas where groundwater discharges to the surface. Typical fen vegetation includes sedges and mosses, along with some grasses, reeds, low shrubs.
		wetland=*	others
landcover=grassland	Area dominated by upland grasses.	grassland=natural	Natural/semi-natural grassland.		landuse=grass natural=grassland natural=fell natural=tundra
		grassland=savanna	Natural grassland with sparsed trees or scrubs.
		grassland=tundra	Alpine tundra: habitat above the treeline, characterised by open, low growing vegetation.
		grassland=urban	Urban/recreational grassland.
		grassland=meadow	Area of grassland, used for hay or pasture. landuse=meadow
landcover=plantation	Land used for growing crops or fruits.	plantation=cropland	Land used for growing crops. landuse=farmland. See crop=*.
		plantation=orchard	Plantation of fruit trees or shrubs. landuse=orchard
		plantation=vineyard	Plantation of grape-bearing vines. landuse=vineyard
		plantation=aquatic	Cultivated aquatic or regularly flooded areas.
landcover=woodland	Area characterized by tree cover.	leaf_type=broadleaved	Broadleaved vegetation.		landuse=forest natural=wood wood=*
		leaf_type=needleleaved	Needle-leaved vegetation.
		leaf_type=mixed	Broadleaved and needle-leaved vegetation.
			managed=yes Woodland is managed/maintained.
			leaf_cycle=evergreen/deciduous/mixed Leaf phenology.
			cover=closed/open/sparse Proportion of a particular area covered by plants.
landcover=shrubland	Area characterized by woody vegetation with aerial stems, generally less than 6 meters tall, without interlocking.	shrubland=scrub	Uncultivated land covered with bushes or stunted trees.		natural=scrub natural=heath natural=tundra
		shrubland=heath	Vegetation dominated by dwarf shrubs of the heather family.
		shrubland=tundra	Arctic tundra: treeless habitat, characterised by open, low growing vegetation.
landcover=bareland	Bare(barren) land, with little or no "green" vegetation.	bareland=sand	Area covered with sand.		natural=sand natural=beach natural=mud natural=bare_rock natural=bedrock natural=rock natural=scree
		bareland=bare_soil	Area covered with earthen material.
		bareland=hardpan	Hardpans are surfaces that have been indurated due to chemical or physical processes. Also dry lake, salt pan.
		bareland=gravel	Area covered with loose rock fragments. Scree, gravel beach.
		bareland=stones	Area covered with stones. Stone desert.
		bareland=bare_rock	Area covered with bare_rock.
landcover=artificial	Artificial surfaces and associated areas.	artificial=road	Area covered by wide roads.		landuse=railway
		artificial=railroad	Area covered by wide railways.
		artificial=pipeline	Area used for communication lines/pipelines.
		artificial=urban	Urban area. landuse=residential
		artificial=industrial	Industrial area. landuse=industrial
		artificial=extraction	Extraction sites. landuse=quarry
The values are somehow sorted by height of the vegetation zone. Many values relate to the NLCD 92 Land Cover Class Definitions. Some values relate to the Land Cover Classification System (LCCS).