User:Innesw/draft landcover

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This proposal page is still an incomplete draft. Please don't edit it or add comments yet.

Proposal

Background

This is a revision of Rudolph's landcover proposal.

In theory both landcover=* and landuse=* should be able to cover 100% of the earth's surface. Landcover describes what is actually on the earth's surface, while landuse describes a human-ascribed use to an area. Values for either may imply values for the other, but the implications are not invariable and can be changed.

Notes on changes to the table of landcover values from Rudolph's proposal are on the discussion page.

Transition

General

The current natural=* is "Used to describe a selection of Geological and Landcover features." Natural should be used for natural features in the landscape, and not for landcovers. All areas tagged with natural=* should be transfered to landcover=* with an appropriate landcover sub-type. Natural features that are points or un-closed ways should remain as-is.

The use of the term forest for any mapping purpose is problematic. In medieval english it meant 'royal hunting-reserve' (eg: the New Forest in the UK), and implied nothing about tree cover. The fact the land was more-or-less natural but managed for a purpose transferred to the meaning of 'managed treeland', and from there to include the planted, single-species treescapes of today. It is apparent that this is the presumed meaning of the term in Europe and the UK. However it has also come to mean 'natural tree-dominated landscape', for example in phrases like 'the Amazon forest'. In Australia, if you talked about going 'into the forest', the common implication would be of a more-or-less natural treescape, not of a managed, possibly planted one. Further, for vegetation scientists (in Australia at least) forest implies tree cover where the canopy is 'closed' (the branches of adjacent trees usually overlap), and woodland where it is 'open'.


Deprecated tags

Deprecated tags
Deprecated tag Replacement tag Comment
nature=bay landcover=bay

Draft Landcover Page

The following is intended as the contents of the proposed key:landcover page. At present columns for pictures and renderings are not included in the table of values.

Notes on changes to the table of values from Rudolph's proposal are on the discussion page.


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 of whether it is biological or geological. This can be the tallest plants (e.g. trees) or the naked surface (e.g. bare rock).

landcover=* is intended to describe the whole earth's surface with one key. It is not intended for detailed mapping in urban environments, although it is possible.

How to Map

All landcover features are areas, created as a closed way or as a multipolygon.

As landcover=* should (in theory) be able to cover 100% of the earth's surface, gaps between neighbouring areas should be avoided.

There are 9 general landcover values, which can be used if no more detailed information is available.

General Landcover values
Description
landcover=water Area of unvegetated open water or permanent ice/snow cover.
landcover=wetland Area where the soil is periodically saturated with or covered with water.
landcover=bryophytes Area of mosses, liverworts, lichens, algae. See wikipedia:Tundra#Antarctic, but will apply elsewhere (eg: some bogs and alpine areas).
landcover=grassland Area dominated by grasses.
landcover=shrubland Area characterized by woody vegetation with aerial stems, generally less than 6 meters tall.
landcover=woodland Area characterised by tree cover.
landcover=planted Land planted with crops, shrubs or trees, usually broad-scale or in rows.
landcover=bareland Bare (barren) land, with little or no vegetation.
landcover=artificial Artificial surfaces and associated areas.

There are specific landcover values which allow for more detailed description, where it is known.

Specific Landcover values
Description
Water-dominated landcovers
landcover=ocean Open saltwater.
landcover=bay A large body of water partially enclosed by land with a mouth to the ocean.
landcover=lake An area of water surrounded by land.
landcover=river Area of a wide river.
landcover=reservoir Artificial lake, used to store water.
landcover=canal Area of a man-made channel for water.
landcover=ice Area characterized by year-long surface cover of ice and/or snow. Glaciers, mountain tops, polar ice.
Wetland landcovers, without vegetation
landcover=tidalflat A tidally inundated area of bare mud, sand or similar sediments.
landcover=sandy_beach A tidally inundated area of sand.
landcover=gravel_beach A tidally inundated area of pebbles or stones.
Wetland landcovers, with vegetation
landcover=swamp Wooded wetlands that are often flooded for a portion of the year. Swamp vegetation is dominated by trees and tall shrubs.
landcover=marsh 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.
landcover=mangrove Coastal wetlands characterized by salt-tolerant trees, shrubs, and other plants growing in brackish to saline tidal waters. Mangrove is a sub-type of landcover=swamp
landcover=saltmarsh Coastal marshes, exposed to tidal inundation with sea water, therefore characterised by herbaceous plants with special adaptations to saline environments. Saltmarsh is a sub-type of landcover=marsh.
landcover=water_weed Area of water where the surface is covered by floating vegetation, sometimes to a density that it prevents navigation. A common example is water covered in water hyacinth.
landcover=mire Wetlands where the 'soil' is largely decomposed/decomposing plant material, mostly from mosses, and the other vegetation cover is low - usually grasses and or low shrubs. The distintion between 'bog' and 'fen' (the two recognised types of mire) is largely one of water chemistry and the source of the water, so requires specific knowledge not generally available from overhead imagery.
landcover=bog Mires where the chemistry is acidic and the water derived from rainwater alone.
landcover=fen Mires where the chemistry is (usually) alkaline and water derived from surface flows and rainfall.
landcover=reedbed An inundated area dominated by certain tall non-woody plants (reeds, bulrushes etc).
Low-vegetation-dominated landcovers
landcover=grass Areas dominated by grasses, without shrubs or trees.
landcover=meadow Area of mixed meadow-flowers and grasses.
landcover=tundra Area of sedges, grasses and/or dwarf shrubs, beyond or above the treeline.
landcover=savanna Grassland with sparse trees or shrubs.
landcover=urban_grass Urban/recreational grassland, usually mown periodically.
landcover=lawn Frequently mown, usually single-species grass, eg: formal gardens, some sports pitches.
landcover=turf Highly manicured, usually low-cut, single-species grass, eg: golf and bowling greens.
High-vegetation-dominated landcovers
landcover=trees Area characterised by tree cover.
landcover=scrub Uncultivated vegetation dominated by bushes or stunted trees.
landcover=thicket Highly interlocked vegetation, probably impenetrable. Usually vines, canes and similar.
Artificially planted landcovers
landcover=cropland Land planted to annual crops. Usually cereals, but also eg: canola, peas.
landcover=plantation Intentionally planted trees or shrubs (ie:perennial plants), usually in regular rows.
landcover=orchard Plantation of trees or shrubs, from which the fruit is harvested.
landcover=vineyard Plantation of grape-bearing vines.
landcover=aquatic Cultivated aquatic or regularly flooded areas, eg: rice.
Bareland landcovers
landcover=sand Area covered with sand.
landcover=bare_soil Area covered with earthen material.
landcover=hardpan Surfaces that have been indurated due to chemical or physical processes.
landcover=dry_lake Bed of a lake that is usually dry mud.
landcover=salt Salt that is usually dry. Usually the bed of a dry lake, but can be in other locations.
landcover=mud Bare mud that is usually wet.
landcover=gravel Area covered with loose rock fragments. Scree.
landcover=stones Area covered with stones. Stone desert.
landcover=bare_rock Area covered with bare rock.
landcover=sub_surface Where the original land surface has been artificially removed to expose below-soil geology.
Artificial landcovers
landcover=built_up Any of, or a mixture of, residential, commercial and industrial buildings, and associated outdoor areas which are either urban_grass or artificial surfaces.
landcover=building Area covered by buildings.
landcover=waste Accumulated industrial, commercial, domestic or building waste.
landcover=mine_spoil Accumulated extracted geological material.
landcover=surface Use surface=* to specify the material.
landcover=road Area covered by wide roads. A special case of landcover=surface.
landcover=railroad Area covered by wide railways. A special case of landcover=surface.
landcover=pipeline Area used for communication lines/pipelines. A special case of landcover=surface.