From OpenStreetMap Wiki
(Redirected from JA:Landcover)
Jump to navigation Jump to search


Help (89606) - The Noun Project.svg

Logo. 地物 : 土地表面
One example for 地物 : 土地表面


landcover は土地の表面の物理的な材質を記述するために使います。土地表面には grass(草), asphalt(アスファルト), trees(樹木), bare ground(土), water(水), などがあります。これは、landuse=farm, landuse=retail, landuse=quarry のような人による土地の利用を記述する土地利用と区別してください。

現在、 landcover のタグ付けはふつう他のタグに含まれています。例えば、公園は草でおおわれていると想定されます。しかし、場所によっては木や砂や他のものに覆われていることもあります。以下のキーは landcover 属性を暗黙に仮定したり定義したりします。

  • landuse=* - 土地利用の多くは、その表面が何で覆われているかを含意しますが (たとえば landuse=meadow)、そうでないものもあります (たとえば landuse=military)。それが曖昧なものもあります。たとえば landuse=greenfield, は何らかの植物に覆われているか更地であるかのどちらかであることを含意します。土地利用と同様のことが、amenity=*leisure=*tourism=* にもあります。
  • surface=* - 表面の材質をあらわします。土地表面と似た属性ですが、これは元々は経路ネットワークに含まれる線形の地物の表面について記述するために作られたタグであり、そういった目的に合った値をつけることが想定されています。また、これはより広い範囲を持った土地利用の表面のタイプを表すにも使われますが、主に副次的なタグとして使われます。
  • natural=* - このキーのタグの多くは、その表面が何で覆われているかを含意するような自然の地物をあらわします。しかし、一部のタグは natural=beachnatural=fell のように表面が何で覆われているかを明確に含意しないため、surface=* などのタグでより厳密な情報を持たせる必要があります。
  • landcover=* - このタグは、土地表面を直接表現するため、Proposed features/landcover で提案されました。

森林は土地表面をマッピングしにくいでしょう。 詳しくはJA:森林をお読み下さい。 There is not currently a good tag to describe a landcover of trees as opposed to a landuse of timber production for which landuse=forest is appropriate or natural=wood for primary unmanaged woodland. The tag landcover=trees has been proposed for this purpose. In addition, landuse and landcover are often confused. For example landuse=grass actually describes a landcover, not a use. This causes problems as one can not describe an area of railway land as being primarily covered with grass as the landuse tag is used for both purposes.



Purpose Category Comment
泥炭地(湿原) Natural natural=wetland and wetland=bog
Bare earth
草原 Natural Currently landcover is implied by the use of landuse=grass, leisure=park, surface=grass, landuse=meadow, natural=grassland, etc. It is typical that landuse=grass is misused and should be changed to landcover=grass (for example: patches of grass between tracks in railway corridor - area that should be tagged with landuse=railway).
砂利 Natural surface=gravel
Marsh Natural natural=wetland and wetland=marsh
マングローブ Natural natural=wetland and wetland=mangrove
Natural natural=mud
Reedbed Natural natural=wetland and wetland=reedbed
Saltmarsh Natural natural=wetland and wetland=saltmarsh
砂地 Natural natural=sand
やぶ Natural natural=scrub
Natural The natural=coastline tag is used to define the boundary between land and the sea (at the high water mark). The boundary between the land and the sea is rich in different landuses, see 'gravel', 'mangrove', 'saltmarsh', 'sand', 'swamp' and 'tidal flat'.
Swamp Natural natural=wetland and wetland=swamp
Tidal flat Natural natural=wetland and wetland=tidalflat
Trees Natural Currently the landuse=forest or natural=wood are used but neither of these work well for planted and managed trees in a park for example.
水辺 Natural waterway=riverbank,natural=water,man_made=reservoir. See also: 'sea'.


Systems of Landcover classification

The landcover classification systems mentioned in the following are all based on the notion that all land surface can be classified into a limited set of landcover classes, either a fixed a priori classification or a dynamic set of a certain number of classes. Since OpenStreetMap uses a globally uniform but open tagging system - see 何でも好きなタグを - neither of these can be directly translated into OSM tag combinations.

A priori and a posteriori systems

In an a priori classification system the classes are abstractions of the types actually occurring. The approach is based upon definition of classes before any data collection actually takes place. This means that all possible combinations of diagnostic criteria must be dealt with beforehand in the classification. The main advantage is that classes are standardized independent of the area and the means used. The disadvantage, however, is that this method is rigid, as some of the field samples may not be easily assignable to one of the pre-defined classes.

A posteriori classification differs fundamentally by its direct approach and its freedom from preconceived notions. The approach is based upon definition of classes after clustering similarity or dissimilarity of the field samples collected. The advantage of this type of classification is its flexibility and adaptability compared to the implicit rigidity of the a priori classification. The a posteriori approach implies a minimum of generalization. This type of classification better fits the collected field observations in a specific area. At the same time, however, because an a posteriori classification depends on the specific area described and is adapted to local conditions, it is unable to define standardized classes. Clustering of samples to define the classes can only be done after data collection, and the relevance of certain criteria in a certain area may be limited when used elsewhere or in ecologically quite different regions.

NLCD92 - National Land Cover Database

National Land Cover Database (NLCD) is a land cover classification scheme that has been applied consistently across all 50 United States and Puerto Rico. NLCD is based primarily on Landsat satellite data.

NLCD 92 Land Cover Class Definitions
Main class Sub-classes Picture
Water 11 Open Water
12 Perennial Ice/Snow
Lake Billy Chinook, Deschutes National Forest, Oregon (photo by Bob Nichol).jpg
Developed 21 Low Intensity Residential
22 High Intensity Residential
23 Commercial/Industrial/Transportation
Barren Land 31 Bare Rock/Sand/Clay
32 Quarries/Strip Mines/Gravel Pits
33 Transitional
Hörnlihütte weg.jpg
Forested Upland 41 Deciduous Forest
42 Evergreen Forest
43 Mixed Forest
Shrubland 51 Shrubland Starr 010831-0016 Morella faya.jpg
Non-Natural Woody 61 Orchards/Vineyards/Other Aerial View - Landschaft Markgräflerland1.jpg
Herbaceous Upland Natural/Semi-natural Vegetation 71 Grasslands/Herbaceous Konza1.jpg
Herbaceous Planted/Cultivated 81 Pasture/Hay
82 Row Crops
83 Small Grains
84 Fallow
85 Urban/Recreational grasses
040719 172 dorset marnhull2.jpg
Wetlands 91 Woody Wetlands
92 Emergent Herbaceous Wetlands
Cepkeliu marsh.jpg
See USGS landcover classes.

NLCD92 Colour Classification FINAL.jpg

LCCS - Land Cover Classification System

The Land Cover Classification System (LCCS) is the result of an initiative to take a first step towards an internationally agreed reference base for land cover. The objectives of the Africover Programme of the Environment and Natural Resources Service (SDRN), FAO, are to develop an approach for conceptualizing, defining and classifying land cover.

Definition: Land cover is the observed (bio)physical cover on the earth's surface.

One of the basic principles adopted in the new approach is that a given land cover class is defined by the combination of a set of independent diagnostic attributes, the so-called classifiers. There are 83 main classifiers (Type A), 13 Type B, 19 Type C, 3 Type D, 7 Type E, 10 Type F, 2 Type G (numbers are not approved).

The creation of the land cover class is given by the combination of a set of pre-defined pure land cover classifiers. This set of classifiers is different for each of the eight main land cover types. E.g. trees can have classifier A1 or A3; shrubs can have A2 or A4; B1 stands for large to medium sized fields or height 7-2m or Dunes.

The main criteria is the uppermost canopy layer. This means that the dominant layer goes from Tree canopy to Shrub to Herbaceous/Forbs/Graminoids.

The user can describe up to three layers of stratification (including the main layer) for Terrestrial Vegetation (A12) and up to two layers in Aquatic or Regularly Flooded Vegetation (A24). "Tree Savannah" is clearly defined by two main elements: a Herbaceous vegetation layer and a Sparse Trees layer. Thus, the Stratification of the two elements Herbaceous and Tree layer is crucial for the definition of this class. "Closed Forest" is clearly defined by the element of a Closed Trees layer. Limitations have been introduced for this class in the use of Stratification. All limitations in use of Stratification are built into the software application.

It is crucial where the classifier (e.g. trees) appears, in the main layer or second or third layer.

Examples for results of LCCS-Code in main type A12. Natural and Semi-Natural Vegetation:

  • A3.A10 - Closed forest
  • A3.A10.B2.C1.D1.E2 - Broadleaved dedicious forest
  • A3.A10.B2.C1.D1.E2.F2.F5.F7.G2 - Multi-layered broadleaved dedicious forest
  • this combinations have a completely different meaning in other main types
LCCS Landcover Classification
Main types Classifier Classifier Classifier Picture Some possible results after classification
A11. Cultivated and Managed Terrestrial Areas A1. Trees A7. Broadleaved Leaf Phenology Lemon Orchard in the Galilee by David Shankbone.jpg Tree Crops
Shrub Crops
Herbaceous Crops
Graminoid Crops
Non-Graminoid Crops
Managed Lands
A8. Needleleaved Leaf Phenology
A2. Shrubs A7. Broadleaved Leaf Phenology Aerial View - Landschaft Markgräflerland1.jpg
A8. Needleleaved Leaf Phenology
A3. Herbaceous A4. Graminoids Okolí Huklivého 001.jpg
A5. Non Graminoids 040719 172 dorset marnhull2.jpg
A6. Urban vegetated areas A11. Parks
A12. Parklands
A13. Lawns Traffic Island, Coulby Newham - geograph.org.uk - 91699.jpg
A12. Natural and Semi-Natural Vegetation A1. Woody A3. Trees Cover
Leaf type
Leaf Phenology
WaldAlfeld.jpg Forest
Sparse Vegetation
A4. Shrubs Cover
Leaf type
Leaf Phenology
Starr 010831-0016 Morella faya.jpg
A2. Herbaceous A5. Forbs Lüneburger Heide 109.jpg
A6. Gramminoid Konza1.jpg
A7. Lichens/Mosses A8. Lichens
A9. Mosses
A23. Cultivated aquatic or regulary flooded areas A1. Graminoids Aquatic Or Regularly Flooded Graminoid Crops
Aquatic Or Regularly Flooded Non-Graminoid Crops
A2. Non graminoids Dili Reisfelder.jpg
A3. Woody
A24. Natural and Semi-Natural Aquatic or Regularly Flooded Vegetation A1. Woody A3. Trees Wetland-marshall-county-indiana.jpg Forest
Closed Shrubs
Open Shrubs
Sparse Vegetation
A4. Shrubs
A2. Herbaceous A5. Forbs
A6. Gramminoid Tourbière 03 - Parc de Frontenac - Juillet 2008.jpg
A7. Lichens/Mosses A10. Lichens
A11. Mosses
B15. Artificial Surfaces and Associated Areas: A1. Built-up A3. Linear A7. Roads 20190825 Autostrada A4 w Krakowie 0957 5675 DxO.jpg Built-Up Areas
Non Built-Up Areas
A10. Railroads Passenger-rail.JPG
A11. Pipelines OilPipeAlaska.JPG
A4. Non Linear A12. Industrial Areas Kraftwerk Moorburg (Hamburg-Moorburg).1.phb.ajb.jpg
A11. Urban Areas New-York-Jan2005.jpg
A2. Non built-up A5. Waste dump deposits South East New Territories Landfill 2.jpg
A6. Extraction sites Arandis Mine quer.jpg
B16. Bare Areas A1. Consolidated A3. Bare Rock a/o Coarse Fragments A7. Bare Rock Hörnlihütte weg.jpg Consolidated Areas
Unconsolidated Areas
A8. Gravel Scree.jpg
A4. Hardpans A9 Ironpan
A10 Petrocalcic
A11 Petrogypsic
Pamukkale 2006.jpg
A2. Unconsolidated A5. Bare Soil Not stony Duerre.jpg
A12. Stony
A13. Very stony La hamada noire du Tademayt 1890.jpg
A6. Loose and shifting sand Not stony Libya 4608 Idehan Ubari Dunes Luca Galuzzi 2007.jpg
A12. Stony
A13. Very stony 260 Boa Vista.jpg
B27. Artificial Waterbodies, Snow and Ice: A1. Artificial Waterbodies A4. Flowing MurtfaltalrDanubeChannel.JPG Artificial Waterbodies
Artificial Snow
Artificial Ice
A5. Standing Lakevyrnwysummer.jpg
A2. Artificial Snow
A3. Artificial Ice
B28. Natural Waterbodies, Snow and Ice: A1. Natural Waterbodies A4. Flowing Wilke.Aussicht.01.jpg Natural Waterbodies
Natural Snow
Natural Ice
A5. Standing Mount Pinatubo 20081229 01.jpg
A2. Natural Snow Cotopaxi volcano 2008-06-27T1322.jpg
A3. Natural Ice Grosser Aletschgletscher 3178.JPG
See Land Cover Classification System (LCCS).