User:RicoZ/What is needed

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General concepts

  • probability/density maps (with gradients if possible)
  • overlapping areas with clearly defined semantics
  • minimizing multipolygon mess

Geology

Level model (overlapping areas mentioned above) allowing modeling of

Vegetation

Level model (overlapping areas mentioned above) allowing modeling of

Water and landcover

Level model (overlapping areas mentioned above) allowing modeling of

  • deepwater/shoal/tidal - mapping of reefs, rocks,ridges surfaces

Landforms and landscape features

Most landforms and landscape features are currently covered by natural=*, some under geological=* or elsewhere and mixed together with geological and vegetation features.

See also

  • FGDC

Concept

Any place can have multiple properties in parallel determined by geology, vegetation, ground surface appearance and appearance from above.

To handle problems frequently created by imports, low quality satellite imagery, and automated image tracing those can be assigned special namespaces.

Landcover

Define landcover:above, landcover:ground and vegetation/geology/ground levels as more specific "overrides" for landcover/natural/landuse. Those are areas, and the different "levels" may have distinct boundaries.

  • landcover:above=* - visible landscape appearance as seen from above on high quality satellite/aerial pictures, where most objects like larger trees and small highways would be visible
  • landcover:ground=* - visible ground appearance as seen by a standing person

Old natural landcover and landuse tags

Some natural=* combinations like natural=ridge will be unaffected.

Other natural=* combinations that can be better described with landcover:* will be obsoleted, typically those describing vegetation or rock types. The new tags are more specific easier to combine with other features and it is expected that data consumers will prefer them over the old combinations when both are available.

landuse=* may coexist in many ways with the new landcover tags. For example an area landuse=quarry may include/overlap several areas like landcover:ground=vegetation, landcover:ground=bare_rock or shingles, perhaps some water areas.

Some landuse=* combinations used essentially as synonym for landcover will be obsoleted where the new tags are more specific.

Lowres imagery and landcover

Areas mapped with lowres imagery typically tend to become large polygons of low accuracy marked with attributes like source=landsat or similar. This creates significant headaches later when highres imagery or ground surveys becomes available - mappers typically can not fix the complete area mapped by the old polyogons because they know only part of it and/or the old polygon covers a too large area to fix in one go. Currently mappers could split the old polygons to exclude the reworked area and map it anew or try to correct the old poylgons piece by piece - and at some point remove the source=landsat. Both approaches are tedious and many mappers hate to touch such polygons.

It is proposed that such areas be in future mapped with landcover:lowres=*. Once high res imagery or ground survey information becomes available for parts of the area those parts can be mapped using landcover:above=* and landcover:ground=*, the old landcover:lowres=* polygons will be left untouched as long as they are not completely obsoleted by more precise mapping. Data consumers can select the most precise and fitting data source for their purposes.

Imports and landcover

Imports of landcover data and data generated by picture tracing methods have their specific problems. Mappers may want to change or correct the imported landcover data either because it became outdated, was inaccurate, contained errors - or because other changes in the mapped area require the change. However, this causes significant problems if new more precise/more actual import data becomes available. Changing only the parts that have never been manually touched is technically very difficult and will typically miss many improvements of the newly available dataset.

Sometimes the official data imports may conflict with ground truth but nevertheless may be relevant for special data layers.


landcover:import:*=*

Values

Values can be "vegetation", "ground","bare_rock","shingles","water" etc. It can be multivalued with percentages.

Landcover:* values are complemented by the definition vegetation, vegetation levels, geology and man made structures/landuse.

In principle, the more specific tag/value combinations override the general tags. However, the mapper and data consumer/renderer viewpoints ought to be considered separately:

The mapper

The mapper, an individual with particular and frequently imperfect knowledge will ideally specify those tag/values combinations for areas that he knows well and feels confident. Consider a mushroom searcher; he is little concerned what his area looks viewed from outer space or from bellow the earth but wants to map "the damned thorny bushes area" and will have interest it the topmost soil horizon. A pilot flying over the area will mostly map landcover:satellite=* and keep an eye on even grassy areas suitable for emergency landings. A birdwatcher may complement the information by providing description of the vegetation:shrub=* and/or vegetation:canopy=* levels. A geologist in the same are will try to map geology:bedrock=* and geology:sediment=*

The data consumer

The data consumer/renderer will pick whatever it can and wants to use. Large scale maps will use landcover:satellite to render larger areas in light or dark green, grey, brown or yellow. Hiking maps will give a higher priority to rendering of landcover:ground + vegetation:shrub.

Transport or administration overview maps instead may give a higher priority to landuse and various man made tags.

Vegetation and levels

  • vegetation=* - dominant visible vegetation pattern visible from above roughly similar to natural/landuse vegetation related values. Can be multivalued and values can have percentages such as "forest:50;scrub:30;grass:10"
  • vegetation:canopy=* - canopy level level

Values

Values can be from most general to most specialized:

  • yes
  • forest, scrub, grass and other values common for natural/landuse vegetation related flags
  • multivalued, separated by ";", with percentages such as "forest:50;scrub:30;grass:10"

More specialized values such as particular plant species should go into vegetation levels.

Levels

Values could be layman terms like broadleaf/coniferous/mixed, some values of trees=* or values such as used in taxon=*, genus=* or species=*. Can be multivalued with percentages such as oak:35,birch:10

Aquatic vegetation

Wetland vegetation


  • Reefs etc ???? Not really vegetation but perhaps might be covered in as similar manner

Indoor and man made terraces vegetation

Use prefix indoor, eg vegetation:indoor:wetland:canopy=*, together with appropriate tags from Simple Indoor Tagging and/or Simple 3D buildings.

Ground and geology

landcover:ground defines if anything of this is surface visible